How to Repot Your Plants Step by Step

Container plants can get a much-needed boost if they are repotted. Most healthy container plants outgrow their pots. They can show many signs that they need rejuvenation, so pay attention to your plants and take action when you see them. Learn how to repot your plants step by step. 

When to Repot Your Plants?

Notice if your plants look like they’ve outgrown their container, their roots are growing out of the drainage holes or roots are pushing the plant up and out of the planter. Plant growth may also be slower than usual or the plant may become top heavy.

Check the soil, as well. If water is sitting on top of the soil and not being absorbed, if the plant dries out quickly or if the soil looks dry or is falling apart, these are signs that your container plant needs to be moved to a new home.

There is no exact timetable to follow on when to repot your plants. Typically, every 12 to 18 months is a good rule of thumb, though some plants are happy to be in the same container for years. The best time to repot plants is in the early spring, right before the growth season begins, but it can be done whenever you notice that it needs to be done.

When the time comes to repot your plants, follow these steps.

Select a Container

When moving a plant from a smaller to larger pot, choose a container that is only a couple of inches larger in diameter than the original. A small plant placed in a container that is too large could suffer in excess wet soil. Containers should have sufficient drainage and a tray underneath to catch excess runoff. Keep in mind that repotting doesn’t always mean moving a plant to a new container. A previously used pot should be thoroughly cleaned and rinsed so no lingering disease is transferred. Most importantly, repotting means fresh nutrients to give your plant a new start.

Water Thoroughly

Before you go through the repotting process, water your plant in the old container thoroughly. Plan to do this a day or two before you move the plant. If the soil is damp, it will hold together better and allow you to remove the plant with ease. Check the new potting soil, and if it feels dry, add some water to it too.

Remove the Plant

Turn the container sideways, hold the plant gently by the stems and pull it out. You may have to tap on the sides or the bottom of the pot or give the stems a gentle tug. A root-bound plant usually slides out in one piece. But if a lot of loose soil comes out with, that may be a sign it doesn’t need to be repotted. Take a look at the roots to be sure. They should be white or light in color. If they are dark in color or smell, that may indicate disease. To remove a stuck plant, run a knife around the edge or gently press the sides of the pot if it is a flexible plastic to encourage it to come out. 

Loosen or Cut Roots

Once the plant is removed from the container, loosen the roots and unbind or cut through tangled ones. This helps promote better nutrient absorption. Trim extra long roots, even removing part of the root ball if necessary. You may even make some vertical cuts in the root ball and cut through roots growing in a circular pattern to revive the plant when repotted. 

Prepare the New Container

Remove about a third of the old potting mix, then pour a layer of fresh, pre-moistened potting soil into the container. Place the plant on top, then fill in with potting mix until the plant can stand on its own. Don’t overdo the amount of soil or pack it in tightly. Allow the roots some space to breathe, and leave about an inch from the top of the planter unfilled. This will allow water to be absorbed, rather than running over the edge of the container.  

Water Your Repotted Plant

To complete the process, water your plant in its new container thoroughly and add plant food. It’s best not to stress the plant after moving it, so maintain the temperature, light and watering it gets. 

Looking for new containers for your repotting needs? Call our friendly representatives at 800-531-4769 for assistance or visit www.GothicArchGreenhouses.com to view our selection!

Most Efficient Ways to Water Plants in Your Greenhouse

Greenhouse Irrigation Most Efficient Ways to Water in GreenhouseMany different types of greenhouse irrigation can be used to properly water the plants in your greenhouse. This article will give you tips on how to efficiently water the plants in your greenhouse regardless of the irrigation method you use. 

Automated greenhouse irrigation systems can help uniformly water plants in a greenhouse, but these systems may not be practical for a hobby gardener or a small grower.  

There are several factors that determine when and how much you should water your plants. Consider these tips to ensure you are doing that most efficiently.

Greenhouse Irrigation Tips

Tips on When to Water:

The color or the moisture level of the growing medium is a good indicator of when a plant needs water. As the surface color becomes lighter, it’s usually time to add water. Another test is to squeeze some of the growing medium in your hand, and if little to no moisture is present or if it falls apart, the plant should be watered. Use this as a general guide, as crop type, time of day, current season and weather also affect when water is needed.

Tips on How Much Water to Apply:

Growers can apply less water at more frequent intervals to avoid saturating the growing medium. The growing medium can also be purposefully saturated to retain more water. Either way, the growing medium will need sufficient time to dry. Shallow watering helps prevent root disease, particularly earlier in the plant’s life cycle. Too much water can result in root disease or slower growth rates. The challenge with each method is providing plants the same amount of water.

Tips on Watering by Season:

Day length, sun intensity and temperature determine how quickly growing medium dries out. During sunny spring days, plants may need more water because the medium will quickly dry. On cloudy and rainy days in the spring, plants may need less, especially closer to the evening. Plants that don’t have a chance to dry out can be susceptible to mildew and fungus. In winter, plants need even less water because the growing medium dries out slower. Plants watered earlier in the day will be able to dry before the sun sets.

For hobbyists and smaller growers, hand watering may be sufficient. It allows the gardener to evaluate the condition of their plants and take action if any signs of disease or pests are present. Irrigation systems help ensure that plants receive the amount of water they need when they need it. 

Gothic Arch Greenhouses has the irrigation systems you need! Call us at 800-531-4769 and let our knowledgeable experts help you select the one that’s right for your operation.

 

How to Protect Your Greenhouse Plants from Pests and Disease

How to Protect Plants from Pest and Disease Gothic Arch GreenhouseGreenhouse growers aim to create an ideal environment in which plants can thrive year round.

Along with managing temperature and humidity, keeping pests out and preventing the spread of disease are important.

The best way to protect greenhouse plants from pests and disease is by keeping it clean and consistent.

By not only controlling the greenhouse environment, but also what you introduce into it, you can set yourself up for a successful growing season.

Keep Greenhouse Environment Clean

Pests and disease can spread quickly in an untidy environment. As part of your regular maintenance routine, wash all surfaces, clean pots and disinfect tools. Remove dead leaves and other old plant matter to eliminate insect food sources. Get rid of all standing water. When working with plants, wash your hands before and after. Promote air circulation by giving each plant plenty of room to grow. Growers can empty their structure annually to clean all surfaces, check all doors and supplies for damages, and make repairs. 

Keep Greenhouse Environment Consistent

Keeping the environment consistent throughout the greenhouse helps eliminate the hot, humid conditions in which pests and disease thrive. Some experts suggest natural ventilation systems are an ideal way to create those uniform conditions. Not only does the fresh air help control temperature and humidity, but it also contributes to transpiration and cell wall strengthening, beneficial for creating healthy plants. Automated climate controls can also have the same effect by creating consistent temperature and humidity to prevent the spread of pests and disease.

Inspect Greenhouse Plants Regularly for Pests

As a gardener, one of your most important tools is observation. Make time to inspect your plants regularly to identify and address signs of pests or disease before they get out of hand. Check your plants–or at least a smaller group of them–every day. Take note of spotted leaves, insects, insect skins, groupings of dying plants or unusual growth. If you suspect any plants are infested or diseased, remove them from your greenhouse and dispose of them right away.

Isolate New Plants in Greenhouse

Pests can also enter the greenhouse when you introduce new plants to the environment. When bringing in new plants, keep them isolated in an aquarium with a tight-fitting lid for up to two weeks to ensure no signs of bugs or diseases are present. Once you are sure that no pests or disease are present, you can safely transplant your new plants into your greenhouse. 

Use Barriers and Traps in Greenhouse

Growers can use barriers, screens and traps to protect plants from the vast majority of pests. Insect screens over vents, windows and other openings are effective, but they limit the amount of sunlight that gets inside the greenhouse. Floating row covers and sticky traps are commonly used to provide protection. Sticky traps placed under benches, close to vents and near windows and doors will help you monitor pest activity.

Tips for Using Pest Controls in Greenhouse

Choosing between chemical or organic methods of pest control is a personal choice. While some insects can be harmful to your plants, others are natural predators to those pests. Not all insects are bad! If using chemicals, start by using the least toxic methods of pest control first so there is less damage to those beneficial insects.

Pests and disease target stressed and damaged plants. The best defense against pests and disease is keeping your plants healthy. We can help! Call us at 800-531-4769 or visit www.GothicArchGreenhouses.com for the supplies you need to protect your plants today!

 

How to Design Greenhouses for Your Climate

How to Design Your Greenhouse for Your Climate Gothic Arch Greenhouse Greenhouse for Dry Climate Greenhouses forGreenhouse design is definitely not one-size-fits-all. Areas with low sunlight and heavy snowfall require different structures than a tropical climate marked by extreme heat and high humidity. We will help narrow down the best greenhouses for your climate. 

By understanding their local climate, gardeners and commercial growers of any size can make fundamental decisions about their greenhouse setup. Doing so will allow their plants to thrive and also extend their growing season.

Because a greenhouse provides protection from external elements, determining how the weather and climate in your area affects your plants is essential. Ultimately, the design of the structure is influenced by whether it is shielding them from wind, rain, heat, snow, etc.  

Whether you’re considering a new structure or want to optimize an existing one, these design suggestions—based on the four major climate types—will help you maximize production year after year. 

Greenhouses for Dry Tropical or Desert Climates

For climates marked by extremely high temperatures, low humidity and high winds, a minimalist structure works best. A simple shade structure using insect screen as sidewall protection is the most practical option to manage costs. A misting or fogging system can help increase humidity inside the greenhouse, while also helping to reduce temperatures well below the arid conditions outside. It can upgrade this economical design to include automated cooling systems for even more control over the greenhouse climate.

Greenhouses for Humid Subtropical Climates

Hot, muggy conditions day and night, coupled with heavy rains, require flexible greenhouse designs, as simple as a plastic roof with roll-up sides covered with insect mesh for protection against pests or a more substantial greenhouse that can withstand higher winds and scorching sunny days. Even larger greenhouses may feature open-roof construction to allow for natural ventilation. Heating systems and insulation aren’t much of a concern in this climate, but misting systems, circulation fans and movable screens can help manage temperature, air flow and light intensity.

Greenhouses for Temperate Climates

Temperate climates exhibit seasonal variations in temperature and moderate rainfall year round. An optimal greenhouse design features fully clad walls, roof and sides with large areas to encourage ventilation. A double layer of insulation can significantly reduce heating expenses. Commercial growers in these conditions may find it most efficient to manage heating, ventilation, irrigation and lighting with environmental controls.  These controls help easily maintain optimal greenhouse conditions despite the changing weather. 

Greenhouses for Cold Temperate Climates

In cold, snowy climates, greenhouses should be sturdy enough to handle heavy snow.  Polycarbonate walls and a steep roof pitch will help prevent snow from collecting on top of the greenhouse. Adding supplemental lighting and keeping vents closed will help keep the greenhouse warmer, particularly during colder months.

The experts at Gothic Arch Greenhouses will help you choose the right greenhouse for your climate.  Please call us at 1-800-531-4769 or visit www.GothicArchGreenhouses.com to view our selection of greenhouses.

What You Need to Know About Caring for Hydrangeas

Caring for Hydrangeas Gothic Arch Greenhouse Mobile ALHydrangeas are prized for their big, colorful blooms, and if cared for properly, they will thrive, and their natural beauty will be enhanced.Even if you don’t have much space, you can still enjoy these flowers. Hydrangeas are suited to be grown as shrubs, in containers and in gardens. Just make sure they get enough morning sun (afternoon sun is too hot) and shade (but not too much). Base the amount of sun they are exposed to be where your garden is located. For example, hydrangeas that are further north need more light than those in the south.

If you understand the unique needs of hydrangeas, you can help nurture beautiful, healthy flowers that come back year after year.  

General Care for Hydrangeas

Though hydrangeas may appear delicate, they don’t require a lot of specialized care. They need plenty of water, one inch per week during their growing season. Deeply watering the plants is recommended three times a week to help encourage root growth. Be sure not to get moisture on leaves or the blooms. Providing this much water will protect plants from wilting on hot days.

Adding mulch to the base of the plant will also help keep the soil cool and moist. Plus, as the mulch breaks down, it will provide nutrients and boost the soil texture, especially if it is organic mulch. Finding the right fertilizer for your hydrangea variety will also boost growth and promote the health of the plant.

Hydrangeas tend to be pretty resistant to pests, but inspect your plants often. Typically, the best defense against aphids and red spider mites (pests that can infect hydrangeas) is giving them the proper care.

Hydrangea Pruning

Pruning hydrangeas properly can result in a more plentiful plant. Routinely trimming back dead leaves, flowers and branches will allow enough room for new growth. If your hydrangeas have enough room to grow, your only concern is to prune to remove dead wood and spent flowers. If a whole branch is dead, be sure to cut it off at the base of the plant.

With regular dead-heading, hydrangea plants are encouraged to produce more and bigger blooms. But pruning is important too. There is a growth-inhibiting chemical released by terminal buds at the tips of stems, so without this maintenance, fewer flowers are produced.

Dead-heading will help your plants bloom into the fall. Avoid pruning past August. By then, any new growth may be cut short by an early fall freeze. Allow any early fall blooms to simply fade away on their own, or cut your blooms and enjoy them! Hydrangeas make beautiful arrangements in bunches on their own or with other plants and flowers.

Changing the Color of Hydrangeas

You can change the color of your hydrangea blooms, but don’t expect it to happen right away. The process can take weeks or months! It’s recommended to wait at least two years before trying to make any change, so the plant has enough time to recover from the shock of its initial planting.

Please note that not all varieties can change color. Soil acidity influences the color of the flower—acidic soils (less than 5.5 pH) produce blue flowers; soils with a pH above 5.5 produce pink flowers. Changing the color from blue to pink is easier than changing pink to blue. Also white hydrangeas are unaffected by the pH level of the soil.

If your goal is getting pink hydrangeas to turn blue, don’t get discouraged. It will happen! One recommendation is to cover the base in pine straw, which adds a natural acidity. Other options to lower the pH and increase acidity include adding coffee grounds, eggshells and other compostable items, such as citrus peels. The addition of sulfur or peat moss to the soil can also result in blue flowers, whereas ground limestone can bring forth pink blooms.

To accurately determine which direction to go in, conduct a soil pH test. As you change the soil, continue to test it. A pH level above 7.5 can cause damage to the plant. When fall gets closer, all hydrangeas start to fade, but don’t worry! The plant’s bright, colorful blooms will return in the spring.

Need hydrangea help? We offer containers, nutrients and supplements, benches, carts and more. Please let us know if we can support your gardening efforts! Call us at 800-531-4769 or visit www.GothicArchGreenhouses.com.

When to Upgrade Your Commercial Greenhouse

Commercial Greenhouse Upgrade When to Upgrade Gothic Arch Greenhouse Mobile ALMaintaining your commercial greenhouse can mean more than sealing doors, greasing hinges, and fixing tears or cracks in coverings. For commercial greenhouses, proper maintenance also means making necessary upgrades to keep your operation efficient and your workforce effective. Not only can this result in healthier plants, but also better profit margins.

Commercial greenhouse technology changes quickly. For that reason, consider that a greenhouse has about 10-15 years of useful life in it in terms of its systems, such as heating, cooling, etc. The structure itself may last a lot longer, but planning to upgrade the working parts of your greenhouse operation is necessary to stay competitive.

Planning ahead for greenhouse upgrades can help manage overall costs and keep your greenhouse running at maximum efficiency. Keeping a running inventory of your supplies and equipment will help streamline your upgrade process. 

Commercial Greenhouse Upgrades

Below, you will find several types of supplies and equipment that can be upgraded within your commercial greenhouse, often at a low cost. Upgrading your equipment now will save you money in the long run.

Benching

Benches are great for creating more growing space and keeping your greenhouse organized.  If you have stationary benches, making the switch to movable or rolling benches can help you increase your production area by up to 25 percent. Using benches as shelving for your plants allows you to group them in a way that makes them easier to find and sort. 

Glazing

Glazing, or greenhouse coverings, are becoming more effective at helping to maintain greenhouse temperatures. Manage heating costs by reviewing your glazing. It’s likely you regularly reglaze, but be especially mindful of acrylic and glass, which dulls easily. A greenhouse grade glaze that diffuses light, coupled with an infrared layer that adds energy efficiency is ideal.

Heating

High efficiency heaters help reduce how much energy your heating system uses. Growers can also use horizontal air flow fans to help move warm air throughout the greenhouse. There are many natural gas and propane options to choose from. Other natural fuel sources can be used to boost efficiency even more. 

Ventilation

Making the move to natural ventilation will have a significant impact on your energy costs as well. Roll-up side walls, large roof vents and open roof designs make this a widely available option. Switching to energy efficient fans is an easy way to save money. 

Controls

Controls allow you to manage the temperature and other environmental factors in your greenhouse. Some of the latest technology now combines heating and cooling in one device. By streamlining the monitoring, this helps the systems work more efficiently, that the environment maintains consistent temperatures. 

Irrigation

Upgrading your irrigation systems can be a great way to lower costs. Keeping your irrigation system on a timer so that it comes on at certain intervals helps manage water usage. There are also ebb and flood products available that help recycle water to use over and over again. 

Materials Handling

Automation is one of the newest greenhouse trends. Using automated systems can greatly cut down on your labor costs over time. Many automated options are available, including rotating basket systems, container filling, potting and labeling, etc. Also consider conveyors and carts to move plants, as they offer the most inexpensive option.

Have questions about a particular system or upgrade cost? We’re greenhouse experts! Call us at 1-800-531-4769 or visit www.GothicArchGreenhouses.com.

 

Which Hydroponic System Is Right for You?

Choosing a Hydroponics System Gothic Arch Greenhouses Hydroponic GardeningThere’s no denying that hydroponic gardening is growing—and will to continue to grow—in popularity because of its convenience, efficiency and eco-friendliness. But if you wanted to get in on this hot gardening trend, where do you begin?

Determining which hydroponic growing system you will use is one of the most important decisions you will make. How much you want to spend, what plants you want to grow and your level of gardening experience will guide your decision. 

Basic Wick Hydroponic System:

For beginners who want to get their feet wet with hydroponics, this simple, low-cost system is a great way to try. Ideal for small plants, such as herbs, the basic wick system assembles easily. A container holding your plants over a container holding water and nutrients  connects by a rope or “wick.” The fibers in the wick draw up nutrients from the water to the plants. Small plants like herbs benefit most from this system

Deep Water Culture Hydroponic System (DWC):

Another beginner friendly system in the deep water culture system. This system uses an air pump to distribute oxygen to the nutrient solution. Plants are held in place by styrofoam or plastic and suspended over the nutrient rich water. Ideal for lettuce and other types of greens, the deep water system is great for small spaces. Teachers often use this system to introduce their students to hydroponics in the classroom.

Drip Hydroponic System:

Very popular among commercial and home growers, the drip system is scalable, meaning it can accommodate larger plants that the basic wick and deep water culture systems can’t. Plants such as melons, zucchini, onions and cucumbers thrive in drip systems. A pump and timer recirculate the water and continuously supplies nutrients to the plants.  

Ebb and Flow Hydroponic System:

Ebb and flow hydroponic systems flood the plants with nutrient solution, then slowly drains back into a reservoir for reuse. Such a system is ideal for plants with low water exposure tolerance and need periods of dryness to help with root expansion. Strawberries, tomatoes, beans, spinach and carrots are among the plants that can thrive in this system. Growers can set up a simple or complex ebb and flow systems to meet their growing needs. 

Nutrient Film Technique Hydroponic System (NFT):

The NFT system is popular for the fast growth rate it helps plants achieve. Growers also enjoy being able to grow plants in smaller spaces with this system. Easy to maintain, an NFT system conserves both water and nutrients. It uses no growing medium—which can help save money. Plant roots receive higher levels of oxygen by being suspended in a tray with roots dangling in a nutrient solution. When given enough room and support, cucumbers, spinach, tomatoes, peppers and herbs can thrive! 

Aeroponic System:

Similar to the nutrient film technique, an aeroponic system uses no growing medium. Plants suspend from growing ports and receive a misting of nutrient rich solution as needed. Growers can administer nutrients either automatically or manually. Aeroponic systems can be very simple or elaborate to meet the grower’s needs.  Tomatoes, eggplant, melons, herbs, lettuces, squash and edible flowers flourish because of the higher oxygen levels. 

Still have questions on which direction to go with hydroponics? Call us at 800-531-4769 or visit www.GothicArchGreenhouses.com to get the answers you need to get growing!

potting greenhouse plants

Using Ground Cover to Protect your Plants

Ground cover and low tunnels help growers transition between seasons with ease. Gardeners can prepare for late cold snaps and early heat waves that would otherwise devastate their crops.

Fortunately, ground cover and low tunnels make it easier to manage these changes, as well as offer other benefits. Growers can extend their growing seasons for warm or cool season crops easily

Ground cover and low tunnels are available in multiple widths, lengths and thicknesses to suit a variety of needs. With properly secured edges and careful maintenance between seasons, many covers will last through two growing seasons.

Many growers live in climates that have at least one or to harsh weather months each year. Learn about the types of protection available for your crops and plants and protect your investments year round.

Ground Cover for Heat Retention

If you need more time for warm season crops, plastic, heavy weight row covers will help to trap heat and maintain ground moisture levels. By trapping heat and moisture in the soil, plant roots will grow more quickly. This type of cover is also great for reducing weed growth by blocking the sunlight on the surface of the soil. Rolls of plastic ground cover, plastic mulch and paper mulch are all types of heat retaining covers.

Ground Cover for Heat Protection

Crops like lettuces, broccoli and squash need long-term protection from harsh heat. Growers can use low tunnels to achieve this protection.  A low tunnel consists of a set of wire hoops that bend over the plants. Plastic sheeting is then placed over the hoops to filter out UV rays while still allowing proper air flow.  Low tunnels are available with solid sheeting, or with slitted sheeting for more ventilation.

Your low tunnel hoops can also be covered with protective shade cloth. This adds another layer of protection for your most tender plants. Shade cloth can block up to 80% of the sun’s harsh UV rays creating a much cooler growing area. This is particularly great for seedlings and young plants that require more soil moisture to thrive.

Whatever your reason for using ground cover, we can help! Contact us at 1-800-531-4769 or visit www.GothicArchGreenhouses.com so we can assist you with your order.

Grow Lights Greenhouse Gothic Arch

How Grow Lights Affect Greenhouse Plants

How Light Affects Plants Greenhouse Gothic ArchLight is essential for plants to survive, but the color of grow lights can have a significant impact on how they develop.

With the help of LED grow lights technology, multiple experiments are being conducted to determine how plants react to light when exposed to different colors of the spectrum in terms of height, weight, color, texture and more.

Additionally, shade cloths come in a variety of colors and have the same effect on plants. Colored films are being used on the growing areas of the International Space Station as well!

Below is the general performance of plants when exposed to a particular spectrum of colored grow lights:

Spectrums Available in Grow Lights

Ultraviolet

Prolonged exposure to UV light can be harmful to plants, just as it is to humans. A study confirmed that when UV light exposure is eliminated, plants experience enhanced growth.


Violet

Violet light exposure intensifies the color, aroma and taste of plants. It also improves the antioxidant functions of plants, which naturally helps prevent cell damage.

Blue:

The most influential of all hues, blue light has the most powerful effect on plants. It encourages plants to accept more energy, reduces their water loss, and increases their growth and maturity rates. At least a minimal intensity of blue light is needed indoors for normal plant growth. Plants grown under blue light are shorter and have darker, thicker, and greener leaves than those not exposed to blue light. These attributes may be desirable when growing ornamentals, for example.

Green

Not surprising, since most plants are green, this color has the least effect on a plant’s growth. Green light does, however, enhance the production of chlorophyll and gives plants a greener color. Yet, some research shows green light can have positive effects on growth and flowering. 

Green light plays an important role in gardening, particularly as it relates to people. Without the presence of green light, plants do not appear green to the naked eye. Green light reduces eye strain for employees and helps detect any problems or pest issues. The good news is that white LEDs combine green, red and blue light, which provide the benefits of all three colors.

Yellow

Because yellow isn’t far off from green in terms of wavelength, it also doesn’t have much effect on plants. It has no influence on photosynthesis and, as a result, reduces growth.

Red

By itself, red light can help plants yield more leaves than blue light alone. But together, the combination of red and blue significantly improves plant growth, making it an optimal choice for development.

Far Red

Like red light, far red light plays an important role in plant development. Specifically, far red light affects germination and flowering. Essentially, this light encourages flowering because plants require less time in darkness.

Questions about light in your greenhouse or other growing settings? Let us know! When you call Gothic Arch Greenhouses at 800-531-4769, you’ll always get a friendly representative ready to help you. You can also visit our website at www.GothicArchGreenhouses.com for more information.

Commercial Greenhouse Operations

How to Make Natural Ventilation Work in Your Greenhouse

Natural ventilation has become a preferred option for larger growers, in particular, as energy costs of fan cooling rise. This ventilation method works by supplying cooler air, such as through vents or an open-roof design, to allow the lighter, warmer air to be pushed out. All greenhouses built prior to the 1950s featured a system of louvres and vents to help allow excess heat to escape by pulling cooler air in.

More and more, new greenhouse construction is utilizing these same methods, but retrofitting an existing greenhouse is not significantly more than installing fans and shutters. In many cases, it can be about the same or even less.

Relying on natural ventilation alone will not work if the heat is too great. In that case, evaporative cooling systems are a simple and relatively inexpensive alternative.

Both, however, will require mechanical ventilation through the use of pads and fans, or a fogger system utilizing nozzles through the greenhouse. Mechanical systems can be used in smaller greenhouses, but the larger structures benefit from natural ventilation methods as much as possible.

Besides the energy efficiency and reduced costs it offers, natural ventilation allows for more even crop cooling. Crops are spread evenly throughout the greenhouse, and the grower can adjust the vent openings as needed. This will result in a more consistent crop, which in turn can improve sales and the bottom line.

Naturally cooling large gutter-roof greenhouses has traditionally been a challenge in Southern climates, specifically due to lack of sidewall space and relying on roof vents alone can result in uneven cooling.

Open-roof greenhouse designs eliminate this issue. To combat the heat on particularly hot, sunny days, a shade system can provide additional protection and keep temperatures lower. 

Natural Ventilation Considerations:

Size of Vents

The total combined area of roof and sidewall vents should be the same. They should also be at least 15 percent to 20 percent of the floor area. Gutter-connected designs will need larger roof vents or otherwise an open-roof cooling option.

Location of Vents

Sidewall vents are recommended to be located above bench height to allow outside and inside air to mix before it reaches plants. Again, for gutter-connected designs, roof vent location is more important.

Greenhouse Height

The trend toward taller greenhouses helps improve natural ventilation. This create the buoyancy effect, where lighter, hotter air rises, and also helps keep this air well above plant level.

Greenhouse Orientation

If possible, position your greenhouses where the summer wind follows along the sidewall. That helps use the natural flow of air. To make that more effective, ensure that trees, buildings and other greenhouses obstruct it as little as possible.

Have questions about your greenhouse’s ventilation system? We can help! Call us at 1-800-531-4769, and you’ll reach a friendly, knowledgeable representative every time.