Shade Cloth for Greenhouses

There are many different strategies for controlling the climate inside of your greenhouse. Greenhouse shade cloth is one of the simplest and most cost-effective ways to do so. Shade cloth is used to protect plants from getting burned by intense sunlight and as a way to help keep a greenhouse cooler during the hot summer months.

Benefits of Shading Your Greenhouse

Conventional greenhouse wisdom shares that sun is good for plants, but too much sun can lead to sunburned or wilted plants. Some plants, such as orchids and young vegetable starts are more sensitive to direct sun, benefitting from the filtered light that shade cloth provides. If the greenhouse’s exterior glazing is fully transparent, direct sun may be too intense for these sensitive plants, leading to stress. Less stress means happier, healthier, and more productive plants.

Shade cloth produces a cooling effective that can increase productivity. Plants are more productive when they spend less time above 90℉ which is the temperature at which most plants go into a type of dormancy to protect themselves from excessive water loss by curling up their leaves and reducing photosynthesis. Temperatures over 90℉ can cause plants to lose their flowers, again slowing photosynthesis. Both are strategies that the plant uses to protect itself during times of heat stress. While this is useful for keeping the plant growing during times of stress, it lowers yield and can cause premature bolting in greens and herbs.

Using shade cloth will help to reduce both water and energy usage. With less evaporation of water, the ground stays cooler. With more moderate controlled temperatures in the greenhouse, less energy will be needed to cool the greenhouse, lowering gas or electric costs.

Ways to Attach Shade Cloth to Your Greenhouse

There are several ways to add shade to a greenhouse including shade cloth on the inside, shade cloth on the outside, shading paint on the glazing, roll-up shades, etc. We’ve found that shade cloth panels attached to the outside of the greenhouse are very effective. Shade cloth can be attached to the inside of the greenhouse but outside panels are better at keeping the heat out and are easier to install and remove.

Greenhouse Shade Cloth
Greenhouse with Shade Cloth

Sturdi-Built Greenhouse Shade Cloth

Sturdi-Built Greenhouse shade cloth attaches to the outside of the greenhouse. Different density cloths are available ranging from 47% to 80%, depending on your sunlight levels and greenhouse usage. Our shade cloth is custom cut for your greenhouse model and size, with grommet holes that snap onto provided exterior grade screws.

We use woven polyethylene fabric that is resistant to mildew, abrasion, and UV light. The cloth is also resistant to most acids, alkalis, and solvents. Grommets are installed on taped outside edges that provide a 3/8″ opening, that works well with our provided pan head screws. We customize the shade cloth for your greenhouse.

What Shade Cloth Density Should I Use for My Plants?

Shade cloth fabric density should be selected based on the climate, your plant’s needs, and your growing zone. Factor in your plant variety’s light and temperature needs when choosing your shade cloth density percentage for best results. The general rule is that vegetable gardens in northern climates are fine with 47% to 63% density shade cloth while hotter regions and those in the south where the summer sun is more intense should use 55% to 80%. Most shade loving plants like orchids benefit from shade cloth in the 70% to 80% range.

Here’s an easy guide:

Shade Cloth Density Percentage Guidelines Zone/Crops
30 – 47% Northern Climates (north of 40 degrees latitude): Most vegetables
50 – 55% Southern Climates (south of 40 degrees latitude): Lettuce, Flowers, Tomatoes, mixed crops, and most Vegetables
60 – 65% Ornamentals/Succulents
70 – 80% Hot Climates (over 100%): Light sensitive plants, such as orchids

What Parts of My Greenhouse Need Shade Cloth?

Assuming your location is full sun, shade cloth on the southern and hot west facing sides may be a necessity. Eastern sides depend on the sun intensity in the mornings. Shade cloth on northern sides is rarely needed. For most freestanding greenhouses, this means that you may only need shade cloth for one “half” of the greenhouse. This will include one roof side and one side wall side. For lean-to greenhouses, if your attaching wall is facing west or south, you should order shade cloth for the roof and side wall. Depending on your exposure, climate, and usage, you may also need a piece for one of your gable end walls.

Other Guidelines:

• Most commonly, shade cloth is put on the greenhouse in spring and taken off in the fall. However, it can also be considered a tool – use the tool when you need it and remove it when you don’t. You may experience unexpected heat waves in the spring or fall. Shade cloth is a great way to protect your plants during short spurts of inconsistent weather.

• It typically takes around one year to get to know your greenhouse – within that year you can discover when or if shade cloth is needed. For that reason, you may consider ordering shade cloth after your greenhouse is built. Just remember that if you do choose to order shade cloth later, that means that you may experience days during your first year with your greenhouse where plants are susceptible to overheating and stress.

FAQ’s

What is a good shade cloth fabric?

Select greenhouse shade cloth fabric that is UV stabilized, rot and mildew resistant and abrasion resistant.

When to put shade cloth on a greenhouse?

Most gardeners install a shade cloth system as soon as they install their greenhouse, to give them the option of shading off plants when needed through the planting season. Others will install in spring and remove in fall. When you use it will be dependent on usage, climate, and exposure.

How do I order shade cloth:

Give us a call at 503-244-4100 and speak with a sales representative who can walk through our options with you and provide an estimate. Payment can be made over the phone by credit card or by check. Shade cloth is custom cut for your greenhouse and is made to-order. It typically takes around four to six weeks from the time of ordering to receive your shade cloth, so plan ahead if you need it at a specific time. Because shade cloth is custom cut for our greenhouse models and standard lengths, we do not offer shade cloth for greenhouses from other manufacturers or DIY greenhouses.

What temperature is too high for a greenhouse?

Generally, any temperature above 90°F (32°C) is too hot for a greenhouse. It is recommended that you do everything possible to keep your greenhouse below this temperature. In addition to shade cloth, you may want to consider adding louvered windows, known as “jalousie windows,” to aid with passive ventilation.

How do I install shade cloth?

Sturdi-Built shad cloth uses grommets at the outside edges of the material to hang your greenhouse on the outside. Simply install the provided screws at the grommet locations. Then, you are ready to hang the shade cloth. This often involves being on a step ladder both on the outside as well as inside of the the greenhouse up through the roof vents.

How long does shade cloth last?

When shade cloth is taken care of properly, it can last up to 16 years. Fold up and store shade cloth out of direct sunlight when not in use. Ensure that the shade cloth is completely dry before folding it for storage. Keep protected from insects and rodents by storing tightly rolled inside of a large plastic bag up off the floor.

If you have any additional questions regarding shade cloth and what will be needed for your greenhouse, feel free to give the experts at Sturdi-Built a call anytime at 503-244-4100 or email us at [email protected].