Shade cloth is an essential part of growing with a hoop house or greenhouse. As we like to say at Bootstrap Farmer, “It’s not a matter of if you need shade cloth, it’s a matter of when you’re going to need it.”
If you’re feeling overwhelmed shopping for shade cloth, you’ve come to the right place. This article will not only cover some shade cloth basics, it will break down the difference between two types of shade cloth: monofilament and tape.
Shade Cloth: What Is It?
Shade Cloth is an important tool for any grower. This lightweight, breathable cloth provides UV protection for your plants, helps moderate greenhouse temperatures, and can help conserve water usage.
It also helps to keep your fruit and vegetable plants protected from sun scald and wilting during periods of intense solar radiation and heat. This protection will help increase harvestable yields from plants.
For our purposes, we’ll focus on shade cloth for plants and greenhouses. But it’s worth noting that certain types of shade cloth (also called sun sails) can be used on patios or other outdoor spaces.
So, how do you use shade cloth in the garden or on your farm? It is most often used with a greenhouse or hoop house structure. In conjunction with proper ventilation, shade cloth allows growers to use their hoop house all summer long. You simply drape it over the plastic and clip or lock channel in place.
In very warm climates, growers use it to create shade tunnels by simply attaching it tightly over the hoops without a layer of greenhouse plastic underneath. Only monofilament shade cloth is strong enough to be used in this manner.
Monofilament vs Tape Shade Cloth
Tape shade cloth is a cost-effective and lightweight option for many growing uses. It has a high shade efficiency, but is not as strong as monofilament shade cloth.
In general, monofilament shade cloth will hold up better to extreme wind, sun, and weather. It doesn’t stretch and, therefore, can be pulled tighter across a structure and even installed directly over bare hoops.
Monofilament Shade Cloth
Stronger than tape
Less affected by the wind
Can be pulled tighter across the structure
Can install over bare hoops without plastic
Good for use in warmer climates when you don’t want plastic, but just want shade
Great for 4' low tunnels with clamps.
Tape Shade Cloth
Cost effective shade cloth solution
Versatile and lightweight
Not recommended to use on a hoop house greenhouse by itself, need to use with plastic.
Knitted vs Woven Shade Cloth
When shopping for shade cloth, you may have come across both knitted and woven types. This refers to the manner in which they are manufactured. We can special order woven varieties for customers, but we mainly carry and recommend knitted shade cloth.
Knitted shade cloth doesn’t unravel. You can cut the ends and it doesn’t need any special treatment to seal it. This offers a lot of convenience in the garden as you can quickly and easily adjust the size needed.
This also increases the value because you can purchase a larger amount and then easily cut it to fit your desired uses.
How to Choose Shade Cloth Percentage
Shade cloth comes in a variety of colors and percentages. The shade cloth percentage is the amount of light that is blocked by the shade cloth. This ranges from 30-50%.
In general we recommend that growers located North of the 40th parallel use 30% shade cloth and that growers south of the 40th parallel use a 50% shade cloth.
When to Install Shade Cloth
The most important thing is to have the shade cloth on hand before you need it. I can’t tell you the number of times we get panicked orders because a farmer is experiencing a heatwave and desperately needs shade cloth - now!
Learn from their mistakes and be prepared ahead of time. Rush shipping on something this large can be costly but if you order early any shade cloth will ship free from us within the contiguous 48 states.
As a general rule, you’ll want to install the shade cloth when greenhouse temperatures rise above 85℉ and keep it on until temps get below that. For our growers in Texas, this means using shade cloth from May to October. Our growers in colder climates often only need to use it from July to September.
You’ll also want to make sure you take your shade cloth off during the cooler months. Ice and snow can easily stick to shade cloth. This can not only damage the cloth, but cause weight to pile up and damage your greenhouse structure.
Will Shade Cloth Make it Cooler in My Greenhouse?
Yes, and no. Shade cloth will definitely help manage the greenhouse effect and prevent your greenhouse from reaching scorching temperatures. As UMass Extension explains, "By reflecting the sun's rays or blocking them so they can't get in, a significant portion of the heat load is removed."
But it will not make it cooler than the outside temperature. Imagine you’re standing outside, in direct sun, on 90 degree day. It feels HOT! Then you go stand under the shade of a large oak tree. Suddenly you feel a bit cooler. But if you were to carry a thermometer, you’d see the temperature is still 90 degrees.
Shade cloth creates a similar situation. It will keep your greenhouse cooler since the greenhouse effect won’t be as strong. But it’s only one piece of the puzzle. For a complete system, you’ll also want proper greenhouse ventilation.
How do you use shade cloth to create microclimates?
Shade cloth is an excellent way to create microclimates in your garden. This allows you to create areas that are shadier, warmer or cooler, more protected from the wind, or have varying humidity points. By planting specific species in the zone they are best suited, you will get healthier plants and increased yields.
What is the best shade cloth for growing tomatoes in a greenhouse?
If you live south of 40 degrees latitude 50% shade cloth is ideal for growing crops like tomatoes. If you are North of the 40th parallel you can go with a 30% shade cloth.
For greenhouses that are right in the middle of the country, going with 50% is better if you are seeing temperatures over 100℉ during the heat of the day.
As we explain in this guide to using shade cloth, it depends on the side of your structure. Begin by measuring the width and length of your greenhouse. The cloth only needs to cover the top down to the hip-board, so don't worry about getting a cloth wide enough to cover the entire width of the structure.
And remember that you can always cut your shade cloth to the desired size. For use over low tunnels or small raised beds, you'll probably want to purchase a larger piece and then cut to the appropriate sizes.
What Color Shade Cloth Do I Need?
Whether you choose black or white colored shade fabric or go with Aluminet will depend on several factors. Your location, the crops you are growing, daytime to nighttime temperature swings, and the desired effect of your shade cloth will all influence the appropriate fabric choice for your farm or garden.
- White shade cloth reflects light and heat, making for a cooler environment for the plants. White shade fabric is better suited for warmer climates as it protects against excessive heat and as such keeps flowering and fruiting plants producing during hot weather. In high temperature areas of the country like Texas and other southern states, white shade cloth will offer greater protection than black.
- Black shadecloth absorbs heat while also blocking excess light. It does absorb heat and can act a bit like a radiator as the heat absorbed by the cloth, if placed close to the plants, can be transferred to the growing crops. Black shade cloth is better for those growing heat-loving crops such as tomatoes and peppers and those in colder climates that benefit from more solar gains in the shoulder season. In some regions where extra heat is undesirable black may not be the best choice.
- Aluminum coated shade cloth, often called Aluminet, also does a great job at reflecting light, but where it shines is in light diffusion. It reflects light and heat similar to white colored shade cloth and also increases full spectrum light diffusion under the cloth (65%).
Many flower farmers have success using shade cloth to keep spring flowers blooming longer. It can also be used strategically to hit important bloom dates (hello Mother’s Day!).
The use of Aluminet shade cloth can also help with nighttime temperatures as it acts as a thermal blanket. In this way, it helps protect plants from wide temperature swings in regions where the daytime and nighttime temperatures are dramatically different.
It is also a great choice for retaining heat in heated structures overnight when installed inside of the structure rather than over the top of the greenhouse.
Shade cloth is an important piece of equipment for gardeners and farmers. It will allow you to provide an ideal environment for your plants and maximize yields.
Remember, it’s not a matter of IF you need shade cloth, but a matter of WHEN you need to use it. Keep those plants happy, greenhouses cooler, and your garden thriving by using shade cloth during the hot summer months.
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