From its origin as a luxury habit for only the wealthy and the privileged, greenhouses are now used in a lot of important and eye-opening ways in helping man understand nature and make use of it naturally. It has found its way in commercial use by feeding world’s population since World War II. Personally, a greenhouse can benefit you in a lot of ways:
- access to fresh greens, vegetable, and fruits as well as fresh cut flowers all year round
- ability to grow thing you wouldn’t be able to in your regular environment or weather
- a warm place to go to during cold weathers
- will protect plants from harsh weather conditions, animals and insects increasing the plant production
- helps lower temperature and manage water loss in plants especially in hot, arid regions
- adds beauty and visual appeal to your landscape
So, you are considering a greenhouse. It’s a major investment that should be planned ahead of time. With a lot of considerations needed to be addressed, it’s hard to know where to start. But today, we will take things little by little by laying out the basic guidelines, breaking up the basic necessities and giving you pro tips that include budgeting, choosing an ideal location as well as weather considerations. Whether you are a beginner or a seasoned professional, you will surely get fresh ideas from this article on how to thing to consider when planning to build a greenhouse in your home garden.
The Perfect Location
There may be only one possible location to put a greenhouse in your garden. But if you do have the options, it’s well worth giving the possible best position you can. With careful site selection, you will optimize the productivity of your greenhouse structure which helps you offset the space it takes up in your garden, the time and effort spent in building one as well as your initial outlay.
You will need a location that has the most exposure to solar radiation.
Your plants need at least six hours exposure to sunlight for photosynthesis. The process is necessary for plants to grow healthy and bear fruits or flower. The best sitting direction largely depends on the season you want to grow plants.
East-West Facing Ridge. Lining up the ridge of the structure to run east to west maximize light interception especially during November to January. The direction will help crops heat up more quickly after cold nights.
South Facing Ridge. This sitting position is preferable only if you intend to grow your crops during summer. The direction will distribute will generate an equal amount of light to each side of the structure and helps reduce too much heat temperature.
Further Note: If possible, avoid the north side part of your home as the plants are limited by the amount of sunlight in this area unless you are willing to facilitate additional source of light and heat. Also, keep in mind that shadowy areas will limit the necessary amount of sunlight your greenhouse will receive. Shade lines differ between summer and winter. It is advised that a greenhouse should be at a distance equal to at least twice the height of any potential shade source.
Recent research also suggests that a site’s latitude should be a basis of your preferred orientation on your structure. For example, for southern latitudes where there is a warmer temperature, a north-south orientation is ideal to provide good light and best ventilation. Further, the strength and direction of the wind should also be considered. Outdoor gardening is quite challenging on windy areas. Opt for a spot where you will have a windproof such as trees but make sure it doesn’t cause too much shadowing
Make sure the site has an easy access to water, electricity and other needed utilities. You will want a location that is near to water access, heat and electricity for convenient gardening. The watering system is essential in gardening especially that a natural source of water such as rain or groundwater is restricted. In laying out one, it is best to study your land profile. Better yet, choose a spot where you can lay out your water irrigation successfully. This also works the same for the electricity needed in lawn mowers, hedge trimmers along with providing power with outdoor lights, pond pumps and greenhouse heaters. Care must be taken to avoid fire and electrocution.
A stable elevated ground is necessary to prevent unnecessary water accumulation. While watering is an essential for the growth of plants, they can also suffer or die from overwatering that mainly cause by rain flood or extra waters coming off the roof. It is best to build your structure to an elevated ground so runoff flows away from the greenhouse smoothly.
Further Note: It is technically possible to orient a greenhouse on a slope but avoid doing so. You will need a higher elevated ground but putting it in a base of a slope will frost pocket where coldness lingers, especially for winter farming.
Find a site where there is a decent soil to grow plants or the potential to become so. If you are not quite sure of the soil’s profile, you will need to hire an expert to analyze the nutrient, texture, and composition of your land’s soil. Poor soil can be improved by digging in organic matter. But unless you will be able to find an area that has excellent gardening soil and natural drainage, little preparation is required when it comes to cultivating it, reducing weed seed bank and adding organic matter.
Further Note: Try to avoid stony or rocky ground as it can be a hiccup in the construction process.
Lastly, a location’s capability of expansion is also nice. The need for expansion is always unpredictable. In the future, you may need a larger space for your growing crops or you may need an increase the number of your plants. It is always ideal to build a greenhouse in a large area to cater to the possibility of expansion.
The Allocation of Space
How much space are you going to need? As mentioned, your chosen location should provide you ample room for expansion for years to come. In addition, the allocated space should justify the borrowed space in your garden. In many instances, greenhouse owners either end up having that extra space they seldom need or wanting more of the square footage. In avoiding these common mistakes, it is necessary to evaluate the factors that commonly take up space in a greenhouse.
The Plants You Want to Fit In. Initially, a compact space is used for seed planting. As plants grow, you will need to triple the space. A 10’ x 10’ is usually the minimum size for potted plants. But less space is required for greenhouses with cabin fevers. In fact, even a 6’ x 6’ is already a treat. For bedding plant farming where gardeners grew plants on the floor, it is necessary to leave enough walking aisle to place 1-foot at least in front of the other. When production time arrives, you can have that working aisle by harvesting the plant first on center area.
Aisles, Walkways and Working Space. It is a common practice to leave enough walking space to observe and harvest plants. Normally, 40 percent of the floor area is for aisles and walkways. With at least 18-inch work aisles between and one three to five-foot main aisle down the center, you will potentially increase growing space by at least 10 percent. This method also provides easy access for moving plants with cart.
Bonus Tip: One meter of space all around the structure is necessary not only for putting up easier access to the greenhouse but also useful in such cases where maintenance issues arise. For example, it will be easier to replace panes or covers or cleaning if you have allocated enough space for walking past. Leaving this space will also mean that fences and other structures are not close enough to block ventilation or cast unwanted shade. Leaving generous space on the front is also wise as the opening door is another way for ventilation and air circulation.
Benches, Racks, Hanging Baskets. These are all extras but also can make the most of the space. Benches are normally used to utilize space for the production area. It works well for crops such as ground cover. 60-90 percent of conventional, lengthwise benches typically contributes to the floor area. Configuration wise, movable trays are more efficient. Other choose to hang baskets to increase space utilization. Hanging basket conveyor are attached to the overhead trusses where plants are spaced eight-inch apart. For larger potted plants, an A-frame rack system can double your growing space. They can be built within 2’ x 4’ lumber and fence pipe or with heavy steel rods. However, if you just need something to put off your plants from the ground, shelves will do the pinch and are boxy to small spaces.
Irrigation and Drainage. These two factors can eat up space. Drip irrigation won’t be a problem for large and big greenhouses, but for a smaller setup, one may be able to efficiently use hand watering. Meanwhile, floor drainage should start with a six to eight-inch gravel or stone base under the floor.
The Kind of Plants You Want to Grow
If you are new to gardening, it’s best to have ideas on what plants that will grow best in your greenhouse. This will depend heavily on your setup as well as the capability of your greenhouse to control environmental factors. However, suitable plants for greenhouse gardening are available for every kind of greenhouse and climate. They are grouped into three categories; Vegetable and Crops, Fruits and Ornamentals.
Vegetables and Crops
For beginners, it’s wiser to start with easy vegetables so that within a year you can get a grip on the basics of growing one. As you a get hands on them you can continue with the complex crops. Here are some examples of easy-to-grow plants in your greenhouse.
Leafy Vegetables. Veggies that belongs to that of ‘salad family’ such as lettuce grows in the same manner, especially when considering the bedding plants.
Peppers. Nearly every variety of peppers can grow well in a greenhouse. They are best placed in a minimum of 15 inches apart and temperatures consistency of above 55 degrees Fahrenheit.
Tomatoes: With ample sunlight and a stable night temperature of at least 55 degrees Fahrenheit, tomatoes can grow exceptionally well in greenhouses.
Microgreens. Packed with nutritional punch, microgreens are ideal for family-oriented greenhouses. These are the tiny tender version of familiar vegetables. Growers like to diversify them by taking varieties such as brassicas, arugula or spicy-type-greens. They germinate them and let these tiny crops grow out for a week or two.
Herbs. Most of the seed-bearing plants are perhaps the easiest ones to grow. Germinating and raising them to require little attention. As long as you have a good control over the temperature of your greenhouse, you won’t encounter any problems growing them. Common popular herbs in greenhouses include basil, cilantro, tarragon, rosemary and thyme
Other Warm Season Vegetables. These summer crops require a high intensity of at least 60 degrees Fahrenheit during daytime and a minimum 55 degrees Fahrenheit at night. Several varieties of vegetable within this classification do well in a greenhouse. These include beans, cucumbers, eggplants, cantaloupe and summer squash.
Other Cold Season Vegetables. Winter vegetables are best to grow in greenhouses since they fail to pollinate in warm temperatures. These crops require a daytime temperature range of 50-70 degrees Fahrenheit and 45-55 degrees Fahrenheit at night. Beets, cabbage, cauliflower, broccoli, carrots, chard, turnips, peas, and radishes are among this cold season vegetables.
Fruits
Growing fruits demands a warm environment. Most fruit trees appreciate temperatures above 50 degrees Fahrenheit while above 60 Fahrenheit for tropical fruits. But even in unheated greenhouses, a range of fruits can all be raised in surprisingly undemanding ways.
Citrus Fruits. You can grow a variety of oranges, lemons, and tangerines in greenhouses. They have the ability to sustain even the coldest weather. They only need a temperature around 55 degrees Fahrenheit for them to germinate and survive winter.
Peaches and Nectarines. Newbies normally prefers peaches as they are nourishing and simple to handle. Together with nectarines, both can be grown in either unheated or cool greenhouse.
Grapes. Growing vines invariably call for high temperatures. With proper ventilation and heating, a greenhouse can be a perfect place to grow grapes. Some varieties of grapes can also thrive inside a cooler temperature, such are Black Hamburgh and Buckland Sweetwater.
Further Note: Grapevines require a lot of room. One vine is, in fact, plenty for a small greenhouse. One meter should be allocated between each vine. It is important to evaluate if growing one will be invasive to your garden space.
Ornamentals
Ornamentals are in demand and can be a good source of income. It beautifies a landscape and can also be a decorative addition to any home. Whatever your reason for growing one, you will surely find a range of ornamentals that do excellent in any kind of greenhouses.
Flower-Bearing Plants. One of the benefits of having a greenhouse is having the chance to produce blooming plants all year round. With the use of appropriate lightings and solar heating, you will be able to grow some of the most exciting and colorful flowers.
- Sun or Shade-Loving Annuals: These graceful ornamentals bear gorgeous pendulous flowers making them ideal for hanging baskets. The petal-filled blooms appear in a number of shades and some selections offer variegated foliage. Each season, gardeners come out with few or more varieties of shade flowers. Among the favorites are Alyssum, Begonia, Lady’s Eardrop, Impatiens, Hypoestes and Angel Wing Caladiums.
- Perennials: These stem flowers are your best sources of fresh cut flowers. Compared to annual plants, perennials can grow for two seasons and flourish exceptionally when grown in a greenhouse because of its ideal regulated temperatures. Normally the plants are grown in a greenhouse during winter and are brought outdoors to fill the garden in summer. The popular arrays that make a perennial garden are Anemone, Tulip Bulbs, Lilies, Asters, Chrysanthemums, Daisies, Gaillardias, Roses, and Hyacinth.
Shrubs and Climbers. Some of these varieties cannot be grown successfully in an open garden and need the protection of a greenhouse. True climbers take up little ground space and are excellent choices for smaller greenhouses while wall shrubs require more ground space. Popular plants are Clematis, Shrub Roses, Wisteria, and Honeysuckle.
Tropicals. Even tropical plants that require hotter temperature can have a place in a greenhouse. If you want to grow something more diverse, greenhouses can be an ideal setting for tropical plants like cacti, orchids, Venus flytraps and other carnivorous plants, providing that you pay close attention to the indoor conditions.
Types of Greenhouses
The type of greenhouse you need depends on where you live and what you want to grow. From functionality to aesthetics, greenhouses are now also being built-up according to design and style. Following are the inspiring greenhouses you may want to consider categorized based on environmental temperature needs, functionality, appearance, and construction.
According to Temperature
Cold Houses (Temperature: below freezing). The method is to start crops early in fall and extend the growing season in spring. It still provides protection for plants despite having no additional heat source.
Cool Houses (Temperature: 45-50F). The design is driven by creating a space that is able to capture as much light and heat from the sun as possible. The heat is redistributed during the night time so that plants that can’t adapt to extreme cold can still survive.
Warm Houses (Temperature: 55F). These greenhouses are particularly designed to operate during the coldest times of the year when sunlight is at a minimum. It provides protection for plants from adverse weather through a transparent roof enclosure normally built low to the ground. The primary function is to allow a broader range of plants to survive.
Hot Houses (Temperature: 60F). This type install supplemental heat. Hot houses are often used to grow tropical plants.
According to Design or Structure
Plethora of designs are available to choose from but the following are most common types use.
A-Frame. A vented roof and side walls are the design’s prominent feature. The key advantage is the minimization of materials that just enough to meet the requirements of the greenhouse productivity.
Gothic Arch. Beyond its state-of-the-art curved roof, a Gothic Arch is well known to resist extreme temperatures. It includes a semicircular frame of either galvanized pipe or conduit and is usually covered with plastic.
Conventional or Post and Rafter. The embedded post and rafters are among the strongest design to support the roof. It maximizes the space usage and provides efficient air circulation.
Freestanding. The growing need for a greenhouse that can be moved or removed gives rise to freestanding greenhouses. This type of greenhouse, as the name suggests, stands independently which lets you place or move them wherever you please. The materials could be a set of hoops that are covered with plastic or frame that runs on rails or skids that can be moved with a tractor or winches. This type is ideal for greenhouses only operates during on a specific season like summer or winter, a freestanding greenhouse is your best bet as it can be removed and put back again conveniently.
Materials and Construction
A greenhouse construction can involve glazing, framing, and laying out the basic foundation. The construction is something you want to last as long as possible to avoid costly repair works. Choosing the best quality materials to support your structure’s strong and sturdy construction is your next big step.
The Foundation
After spotting in that perfect location, the first material you’ll be working with will be the foundation. Choosing the suitable foundation is the tricky part in constructing a greenhouse because this component is critical to the stability of the structure and will be responsible in anchoring it in place. You have two options with the materials but the decision should be dependent on the size and location of your greenhouse as well as your budget.
Wood. Choosing wood as a foundation is one of the economical ways of building greenhouses. It is inexpensive a stable foundation. The simplest and most common type is made from pressure treated wood that is a great option for small greenhouses. Resistant woods such as cedar, redwood, and cypress are popular because they contain substances that inhibit decay. As for the styles, railroad ties and platform construction are common choices for good drainage.
Concrete. This type of foundation is highly recommended for colder climates as it helps eliminate the effects of the ground freeze of the structure. A concrete foundation provides a very stable and secure base that will certainly last you for a period of time requires little maintenance. That is if you set it up right. Building one requires more experience and knowledge in pouring, leveling and smoothing concrete. If you find this method more of a challenge, you can always hire trained laborers to do it for you.
Further note: In building a greenhouse foundation, it is necessary to level the ground after removing sods and weeds. It is also very important to evaluate your building codes before building a foundation. You may need a specific permit or there may be a zoning law that prohibits particular foundation. Alternatively, there may also be a rule that allows you to only you a certain type of foundation.
Framing
Next up, you’ll be taking a look at the materials that are going to be in the actual frame or ’skeleton’ of your greenhouse. Frameworks are necessary to support the construction of the structure. As to what kind of material to use can depend on your chosen covering or glazing. Heavier glazing requires aheavier frame. Here are some materials you may want to consider.
Wood. This is the most common sought material when it comes to insulation and ease of assembly. However, it is important to opt for redwood, cedar or treated woods as other types can result to wood warps when once damp or wet. Wood can also last you quite long in dry climates with proper upkeep.
Aluminum. This low maintenance material doesn’t rust and has tolerance to natural elements such as solar radiation and water. It might not be the strongest, but it provides a good rigid form for glass or polycarbonate coverings.
Galvanized Steel. Durable and inexpensive, galvanized steels require fewer frameworks because the material has strong solid components. However, there should be a proper maintenance as steels can wear and rust.
Polyvinyl Chloride (PVC) Plastic. The best benefit a PVC plastic can offer is limited heat loss that is ideal for greenhouses that operate during winter seasons. They are lightweight, portable and easy to assemble. With this kind of framing, you have to be cautious in choosing covering options. Due to its lightweight, it can only be able to support a lightweight covering.
Odds and Ends
The difference between an average greenhouse and a greenhouse that will last you a lifetime can be determined by the added materials that lend stability. Reinforcing odds and ends are just extras but will help your structure go that extra mile. Following are small additions you may want to consider giving your greenhouse that ultimate strength.
Trussing. Long rods reinforced at the tops insides of framing ribs makes frameworks sturdier. These rods run on each side of rib arches joining them together so the standing structure will less likely to fall over even with extreme wind and adverse weather.
Small Beams. These are added to the frame or foundation to lend similar stability. It can be of wood or metal.
Anchors. Cables that is either tied to weights or staked down straight to the ground are added to weigh down the entire structure. This is normally done after glazing the greenhouse. With the added construction, the greenhouse can withstand high winds and storms more.
End Walls. Additional end frames and doors secures a firm and built to last greenhouses.
Glazing or Covering
Layering the greenhouse cover is the final touch. As mentioned, choosing the type of materials for the panels should be based on the frame setup and vice versa. Additionally, choosing the glazing materials as well as how many layers needed also depend on the amount of insulation.
Glass. Beyond its aesthetic appeal, glass glazing offers great light transmission than any commonly used glazing. It’s a no-brainer that glass structures are fragile. Nonetheless, repair issues that mostly caused by projectiles like hailstones less likely happen.
Plastic. This glazing is lighter and flexible than glass. They are available in larger panes, reducing drafts and making construction easier. Fiberglass is one type of plastic glazing that has a gel coat for UV protection, retaining heat better than glass. Polycarbonate is also a corrugated plastic that is almost as transparent as glass but wears longer than fiberglass. The most inexpensive option is the Polyethylene film which is normally used by gardeners for seed starting.
Greenhouse Floors
Whether you are growing your plants directly on the soil, raised beds, or in a hydroponic system, a greenhouse flooring should not only be able to serve your plants. The floor has to ensure good drainage, insulate greenhouse from the cold seeping ground, and prevent weeds and pests from coming in.Since most of the floor will be used for planting area, the flooring option should be influenced by the chosen planting method.
Soil. Your greenhouse doesn’t need a finished floor surface if plants are to be grown directly on the soil. Varieties and compositions of soil beds are available and the mix you will use you will largely affect the growth of your plants and the success of your greenhouse in general.
Further Note: Old soil mix should never be reused especially that this method doesn’t require plants to be raised from the ground. Ground dwelling pests can easily break in and harm your plants. In such cases where there are dead plants, it should be removed immediately from the greenhouse.
Stone, Gravel, and Pavers. These floor types are ideal for potted plants. Most commercial and residential greenhouses have raised beds directly on the floor, also making stone, gravel and pavers ideal for the setup. It allows the plant root to grow deep into the soil below the grade. Beds with pavers, flagstone, and crushed gravel are also favored materials on walkways.
Concrete. When the method of planting calls for the hydroponic or aquaponic system, self-wicking beds or tables that require a leveled surface, concrete is always a good choice. Though leveled surface can also be done with gravels and stones, concrete has more advantages when it comes to convenience and maintenance. Carts can be moved around easily with the durable and even surface. Also, the concrete slab is a solid foundation that provides additional thermal mass which helps maintain the desired temperature for your greenhouse.
Water Quality and Irrigation
Approximately, one gallon of water mixed with nutrients is needed daily to supply each plant. It is important to determine and make an analysis of the water quality of the greenhouse irrigation as poor quality can be responsible for slow and unhealthy growth and in some cases gradual death of plants. The alkalinity, pH, and soluble salt content are the important factors in determining the suitability of water necessary for irrigating plants.
Further Note: Reconditioning reclaimed water and runoffs or recycled water before use for irrigation minimizes the risk of disease-causing organisms, soluble salts and presence of organic chemicals that may be harmful to plants. Adjustments are as follows:
- Water for irrigation should have a pH between 5.0 and 7.0. Water with pH below 7.0 is termed ‘Acidic’ and water with pH above 7.0 is termed ‘Basic’; pH 7.0 is ‘Neutral’.
- pH levels should be adjusted around 5.8 to 6.5 for vegetables and crops.
- If the source of water is basic more than seven parts per million, and add acids such as nitric, phosphoric and sulfuric.
- If the water is acidic, as in less than seven, and add a base.
Watering Methods
Greenhouse plants are irrigated by means of applying water to the medium surface. It can either be through drip tubes or tapes, by hand using a hose, overhead sprinklers, and booms. Other methods include applying water through the bottom of the container, sub-irrigation or by using a combination of delivery systems. Hand watering is fine but can really be a chore especially if you are working on a large scale and may not efficiently saturate the media to maintain the plant until next irrigation. Depending on the type and size of your greenhouse, a wide range of water systems can be used.
Sprinklers or Overhead Spray. Best for big greenhouses that tolerate wet foliage. This irrigation system is like saturation of a natural rainfall. Water is distributed through the pipe system and then sprayed into the air through sprinklers. The water coming out are small drops which fall to the ground. They raise the moisture level even in unplanted areas which set these unused sections ready for planting.
Misting and Spray System. Works well with bigger scales, use for propagating seeds. Misting works the same as sprinklers but sprays a finer amount of water into the soil. The soft water pressure is ideal for watering seedlings. It gradually hydrates and moistens seeds without disturbing them. They are often in automatic operation which makes the process of watering seem effortless.
Microdrop or Seep Hose System. Efficient water system scalable to any greenhouse size. Alternatively known as drip irrigation system, a microdrop allows water to drip slowly either on the soil surface or directly into the root zone of the plant. The water runs through a network of valves, pipes, tubing, and emitters that are mounted on the media surface or buried within it. The slow dripping nature of the system there is less water waste from the run off without letting the plants dry. Automatic features include releasing water at set intervals throughout the day.
Mat Irrigation. Ideal for smaller greenhouses and novice gardeners. One way to quickly and effortlessly water plants is by placing them on seed capillary mats or self-watering trays. It’s basically a tray with its own water supply often coming from the reservoir. By the time you need to water it, all you must do is top up the main water reservoir and the trays ooze water out in the capillary matting. Since water supply is drawn from the damp ground, it forces plants to grow deeper roots that can harvest more nutrients from the soil. This system is great for seedlings, freshly rooted cutting and other plants that need constant moisture. Topping up reservoirs is normally done once a week, making the method one of the lowest maintenance options which are recommended for amateur growers.
The rising demand for enhancement on water irrigation gives advent to a more innovative watering system which makes the growth of plants consistent and more uniform. Passionate growers are the first one to adopt the system. Their investment allows them to have more free time while machines take care of their plants.
Automated Irrigation System. Measures the moisture of the soil and automatically turns on or off the water system, ideal for large projects. This method is automated and trigger without you having to turn anything on or off. Depending on the set requirements, it works on a timer and provides your plants with the same amount of water. Automated irrigation is useful for big greenhouses where watering manually is time-consuming and inconvenient.
Solar Powered Irrigation System. The best solution to water management with less dependence to company utilities, perfect for small greenhouses. Equipped with solar cells, the eco-friendly irrigation system doesn’t require the use of electricity. It is often in the form of drip irrigation connected to a non-pressured water source that sucks through water at regular intervals throughout the day. This makes it completely self-sufficient and the future of gardening.
Watering Time for Greenhouse Plants
Since you are growing plants in an enclosed space where there is a more control on environmental factors, determining when is the right time to water should be based on the temperature of the greenhouse. For near freezing and mildly cold temperature, water early in the day so the water in the soil acts as a trap for heat and helps the area around your plants stay a bit warmer as night approaches. Meanwhile, in humid conditions, where there is a fast absorption of the moisture of the soil, you can water at least twice a day. Just refrain from watering at the end of the day because there’s a tendency that they don’t get dry before sundown. If the media is damp all night, plants can be more prone to fungal and bacterial diseases.
The temperature of the room largely influences the temperature of the water. Cold surroundings could largely result to cold water temperature, same with a warm or hot environment. And you don’t want to shock your plants with extreme cool or too hot water which could likely damage their tissues. Plants most likely appreciate a nice 90-95 degrees Fahrenheit. In this case, water systems with adjusted temperature range are beneficial. Other several criteria to consider before watering are the planting method, moisture level of the media, the dormancy or stage of the plant and of course the type of plant you are dealing with.
Drainage Solutions
The accumulation of the depleted irrigation water, as well as rainwater from the outside, are the top concerns for greenhouse operators, especially for ornamental growers. Plants can suffer from a lack of oxygen caused by much-wet soil. Also, wet floors are prone to accidents. On the other hand, rainwater from the outside can flash flood waters inside the structure if drainage is not imposed properly. Designing a proper drainage system inside and outside the structure is a must to handle proper runoff of water sources.
Drainage Inside the Greenhouse
The foundation of the floor can play a vital role in handling water accumulation. Start with six to eight-inch gravel or stone base under the floor. This foundation can give you a collection area for over watering in such cases where there no is finished surface or concrete floors laid out. As for the method of drainage, there are two primary methods widely used.
Surface Drainage. The method is accomplished by shallow ditches or open drains that discharge larger and deeper water. The excess water is then facilitated through a created slope. A slope of eight-inch per linear foot is normally the standard.
Subsurface Drainage. The method calls for the removal of water from the root zone. This is done through deep open drains or buried pipe drains with openings so water can enter through the pipe and be discharged.
For your interiors, you can put a trench drain along the sidewalls or post lines. It may cost you more but makes the installation of the floor easier and floor drainage quicker. Incorporating soil mixes that have a good water holding capacity can also be a part of drainage solutions on your planting ground.
Peat Moss. This soft, spongy and fibrous composition is added to overworked soil that lacks structure to increase its water-holding capacity,
Perlite. What appears to be like tiny foam balls often seen in a potting medium is a component of perlite. The roundish white specks aerate the soil, boosting its water retaining properties and enhancing soil drainage.
Coarse Sand. This coarse graded material is used to make soil light and airy for the same purpose of enhancing soil drainage.
Drywell and chamber constructed in the ground facilitate water accumulation for small greenhouses. In larger structures, the drains are normally connected and lead to daylight. In some areas, greenhouse operators collect water either on a vinyl liner or sump installed below to prevent fertilizer and pesticides from getting into the water table. The water stays in the area until it dries.
Roof Drainage
Designing roof drainage becomes a factor that needs to be addressed especially on larger greenhouses where there is more accumulation of water. Greenhouse gutters, downspouts, and drain pipes can be installed to handle excess water on the roof. Downspouts direct the water to lateral pipes that are connected to a larger main. You must be cautious about the spacing as large gaps could result in water flowing over the gutter and into the greenhouse. The standard spacing should be about 50 feet apart along the gutter. For larger installations, it is recommended to install a catch basin at the end of each structure.
Drainage Area Outside the Structure
Another great drainage solution is to design a piping system that collects water and directs it to a pond or a drainage area. A detention pond can prevent water from rushing into the greenhouse in case of heavy rains. At the same time, it fends off flood from its neighboring garden. The large volume of water on the pond slowly releases over several days. In addition, it allows sedimentation, organic matter, and other pollutants to settle out before water is released.
Further Note: There are laws and regulations that govern the discharge of water into another person’s property. In some locations that are covered with inland wetland code, a permit is needed to discharge water into protected areas such as swamps, protected ponds, and marshes.
Environmental Control
Greenhouses can provide its operators the opportunity to have environmental control inside the room, no matter what the weather condition outside is. Having better control means you can host the widest range of plants and can support nearly any type of plants. Depending on your commitment and budget, there are lot of climate control methods as well complex systems fitted with heating, cooling and ventilation systems.
Heating the Greenhouse
Greenhouses shelter plants by trapping solar heat and circulating air to create that artificial environment that can sustain the life when the outdoor temperature is too cool. The method can come handy for 100 percent solar heated greenhouses. But in cold-climate operating greenhouses with little or no supplementary heat, operators come up with creative ways to increase energy efficiency besides orienting the greenhouse towards the sun.
Insulation. Greenhouses uses insulation methods often incorporated in glazing and floor levels as a way of increasing energy efficiency while heating cost. Double glazing, using layers of transparent plastics covers, thermal screens and base cladding the floor are among the popular options.
Cold Frame. Built low to the ground, the transparent roofed-enclosure protect plants from extreme cold emanating from the outside. The transparent top let sunlight in and prevents heat escape via convection.
Thermal Mass. In rooms where there is little exposure to sunlight, thermal mass storages are used to collect and store sun’s energy through water metal-drums. The metal transfers the sun’s heat into the water. The water then radiates the heat back throughout the greenhouse. Other thermal materials that can be used with the same method are plastic tubes and concretes.
Heating Systems. Heating using light fixtures such as radiant lamp suspended over plants is one way to give necessary warmth. Combined with soil heating cables under plants, they create a warm environment. A 220-volt circuit electric heater can also work as artificial heat. There are also solar heaters as well as heating fans designed specifically for greenhouses.
Cooling the Greenhouse
Cooling methods are normally used in humid places and height of the summer where the hot and steamy affair is too much for plants to handle. In addition, some plants require cooler atmosphere for them to grow and that’s when the cooling system come in. Each cooling method has its limits and tradeoffs that one should balance and weigh down.
Shading. Where there is an intense sunlight exposure, shading can keep plants from getting burned by reducing the amount of sunlight. Shade cloths are effective in lowering temperatures by up to 10 degrees. Roll-up screens, wood aluminum, vinyl plastic shading or paint-on materials can also be used to shade plants. The tradeoff that needed to be balanced is between lowering temperatures and losing some necessary solar radiation that is being blocked.
Fans and Vents. Excessive heat is sometimes trapped in the cosseted greenhouse. A good circulation of air can be done through ventilation and fanning. Roof and side vents can create a good through -flow of air while ceiling and exhaust fans create the necessary movement to cool down overheated plants. The only drawback with fans in dry and hot places is it can over dry foliage and planting media if overused.
Evaporative Cooling. As water evaporates, it increases the moisture level in the air. Evaporative cooling uses the natural relationship between humidity, water and air temperature for that cooling effect. The amount of cooling that can be achieved through this method is dependent on how much water can be evaporated, and relatively the humidity or the amount of water already in the air. This method gives rise to the development of evaporative coolers that automatically convert hot air into the cool breeze by using the process of evaporating water. Another system that is developed through this method is the fogging system which generates small droplets of water in the range of 10-20 microns, cooling and providing a reasonable relative humidity.
Water Damping. Wetting hard surfaces can effectively cool down hot humidity. A misting system can be used to deliver a fine spray of water in air space or in walkways. But while misting have its cooling benefit, you have to bear in mind that over wetting a canopy can lead to an increase plant diseases and fruit damage.
Further Note: You can easily feel if the indoor temperature of the greenhouse is hot or cold enough for plants to survive. However, in certain conditions, you cannot always rely on your gut feeling. Through thermometer and other climate-measuring tools, you can monitor an accurate heat or cold temperature of your greenhouse to ensure the optimal growing conditions for your plants.
Plant Pollination in the Greenhouse
Birds, bees, and butterflies are some of nature’s pollinators. The same barrier that protects plants from adverse growing conditions can also prevent the pollinators from doing their job. So how does pollination happen inside the enclosed structure? A little intervention can ensure that plants can be successfully pollinated even in protected greenhouses.
Manual Pollination. It may take a little of your time, but gently tapping flowers releases pollen. Disturbing flowers from male to female plants distribute pollen with each bloom.
Device Pollination. If you can’t fit manual pollination into your schedule, you can use battery-operated pollinating tools. It still needs you as an operator but these tools speed up the task.
Bee Pollination. Bees by nature, are perfect pollinators. Certain bumble bee pollinators can be raised for pollination purposes. You can purchase a box or hive of bees and place in your greenhouse, as long as you also provide the supplemental food source for these pollinators.
Further Note: In a high humid environment, use fans to dry plants before pollinating them. High humidity level can cause pollen to stick together in clumps making pollination efforts unsuccessful. Also, it is best to pollinate plants between 10 am – 3 pm.
Ensuring a Pest and Disease-Free Environment
Good plant health and environmental control is your first line of defense against pests and diseases that bother your greenhouse plants. But in some instances, aphids, whiteflies, and mites can be difficult to control because of their resistance to most pesticides. However, you can still prevent and eliminate pests from lingering throughout by taking the following preventive measures and actions.
- At the first sign of trouble, mechanical controls such as vacuuming, squashing and washing is necessary for biological control.
- It’s best to use soap or pepper sprays if pests continue to grow and multiply.
- Yellow sticky traps are also effective against whiteflies.
- Neem and horticultural oils manage early stages of growth of pests while pyrethroid can kill adult pests.
Meanwhile, fungal diseases are usually the greatest disease problems for greenhouse plants. The same humid temperature that favors many plants can promote these diseases, which is another reason to provide adequate ventilation system. The spacing between plants and monitoring and balancing humidity levels are ways to prevent fungal problems. In such cases where the disease already affected the plants, apply preventive sprays to minimize the affected area and isolate or quarantine the plant. If problems continue to occur, it’s best to dispose of the sick plants as fungi feed more on decomposing organisms.
Safety and Comfort
Safety is one of the major concern in the greenhouse especially when it comes to electricity. Electrical shock is more likely to happen in greenhouses especially with water splashing around wherever you find plants. Avoid wetting heaters and other electrical cables. A safety check should be carried out regularly plus special care should be taken when dealing with electricity to prevent any possible contact between water and electrical connections.
As for flammable materials and gas-powered equipment, placed them far away from the heater. It is a good idea to place smoke detectors and fire extinguisher in case fire breaks in. Proper safety is also paramount to regular working activities. Sometimes, work-related injuries can be up to your own diligence but it is also dependent on a proper maintenance. Necessary repair works, whether on equipment, interiors or materials should be fixed immediately to avoid accidents.
On the other hand, comfort is also necessary to fully carry out well-tended plants and other work necessary for a productive greenhouse. For example, an easier access to the greenhouse can make it better kept especially when maintenance issues arise. Comfort also comes into play if you mix gardening with leisure space. Some incorporate a mini “living space” where they can just sit and relax while observing their plants or reading their favorite books. But whatever you envision your greenhouse will be, both safety and comfort should be considered to carry out that commitment your greenhouse need.
Budget Plans
After studying the several considerations needed to take in planning a greenhouse, you are all set to budgeting. If money is not a problem, allocating budget won’t be too much of a task. In such cases where one is tight on budget, carefully allocating and dividing expenses among the materials, construction labor is a time well spent. But even though you all have that money to spare, it still wise to get some tips and money saving methods in constructing and maintaining your greenhouse. The trick is to allocate budget on the basic necessities first before going on that ‘extra stuff’. Your budget will determine what you can do and put in the greenhouse. The following are the factors that needed to be on your cost accounting list. In addition, we also laid out their respective approximate cost for you to have an idea and better budget allocation.
Greenhouse Size
The larger the greenhouse, the more material it needed. It is necessary to consider how large you want your greenhouse to be if you want to avoid costly expansions.
Basic Beginner (Cost: Approximately $240). Fairly inexpensive, a 6’x8’ hoop structure and greenhouse kits have everything you need to get started. Plumbing and electronics are not included in the estimation. This is an ideal setup for moderate climates.
Experienced Growers (Cost: $3,500-$7,000). A 12’x12’ greenhouse with the covering of normal glass with a vented roof is recommended for more dedicated growers. Many extra costs involved laying the foundation, running plumbing and electrical system.
Serious Growers (Cost: $12,000-$25,000). A 500 to 1000-square-foot is the size for an average greenhouse structure that usually has all of the amenities including automatic watering system, feeders, and grows light. Flooring is often of poured concrete with drainage system
Material Options
The materials that will go into your design will have the biggest impact on your budget. Quality materials are often costly that’s why people tend to shy away from it. It’s good to have a bargain but make sure you are not skimping on the quality needed for that sturdy greenhouse construction.
Covering Materials:
- Glass – about $2.50 sq.ft.
- Polyethylene – about $0.12 per square foot
- Fiberglass – about $72.00 per 6×8 panel
- Polycarbonate – about $55.00 per 8×4 sheet
Framing Materials:
- Wood, Cedar– about $1.00 per linear foot
- Steel -about $2.50 per linear foot
Excavation:
- Concrete – about $10.00 per square foot with texturing and drainage
- Pavers – about $8.00 to $11.00 per square foot on average
- Gravel – about $0.75 to $3.00 per square foot
Construction Labor Cost
Installing Lighting, Heating Ventilation and Air Conditioning (HVAC) won’t be a problem with smaller greenhouses with a simple setup. For bigger projects, it will be hard even for seasoned professional to work alone, not only with these installments but with handling other construction needs. For this reason, you will need to contact licensed contractors to request a bid or quote for the work. Hiring these contractors can make up half to more than your project’s total cost.
Operating Cost and Maintenance
The expenses don’t stop after the construction of the greenhouse. Operating costs involve the expenses to be paid in the plant production such seeds, substrate, pesticides and supplementary plant nutrients. Another primary cost is the utility bills such HVAC and irrigation system. Prior to investing in the construction, it is wise to examine electricity cost in your region. Evaluating the functioning expenses is necessary to determine if you can commit to the operation of a greenhouse.
Building and Zoning Permit
Some large greenhouse installations such as foundations, HVAC, irrigation, and drainage system may require installation permit and has to be done by licensed persons (as mentioned previously). In addition, ‘outbuilding’ or ‘farm building’ greenhouses may require building and zoning permit prior to the construction. It is recommended to consult your local code enforcement officer if the greenhouse you are planning to build fall under the classifications. The purpose of these permits is to evaluate if the greenhouse is a safe place for its owners and operators.
Zoning Permit. If your community is under a zoning code, the officials might require you to illustrate a greenhouse plan that shows the location of the greenhouse with relation to property boundaries and other neighboring structures. This could be the side, rear, or front lines and will be determined by your community’s rules and regulations. Regulations also include accessories and the size of the building under this permit.
Building Permit. In some cases, after the zoning requirements have been met, one may be required to get a building permit. This permit is typically issued by a county department office. The code addresses structural integrity and the physical appearance of your greenhouse.
Further Note: In some communities, a hoop house is not considered a permanent structure and might not require a permit. In others, the owner is required is to provide an engineer’s seal that certifies that the hoop house meets all the code standards. However, every community has its governing rules and regulations. In the end, it still wiser to check with your local codes. The last thing you need is to purchase or build a greenhouse that doesn’t meet the local codes because failure to comply so can result in costly fines or worse, demolition of your major investment.
Build Your Dream Greenhouse Now!
Today’s uncertain economy has many gardeners wondering when is the right time to build a greenhouse. If you consider the many factors mentioned, there is no time like the present. According to experts and analysts, the price of raw materials needed in the greenhouse construction is at their lowest points. If you wait few more years, it will only go up.
After deciding to build your greenhouse, made your finances in order, and followed the necessary considerations you have learned, plan some more. Do as much pre-planning as possible to avoid any roadblocks you may encounter. Once you have successfully executed your plans, you will see that it’s all worth the effort, money and time invested.
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