by Matt Gibson
Every gardener is thankful to have row covers on hand when the temperatures drop. Not only do these inexpensive, DIY insulators protect your plants from cold and wind, they also keep out insects, fight against the spread of disease, and keep soil and plants from overheating. Also known as garden fabric, garden netting, or floating row covers, row covers are super easy to use.
Just drape garden fabrics directly over garden plants or use hoops or a frame to support it, using soil or earth staples to secure the edges and keep it from blowing away in the wind.
What are row covers made of?
Row covers are typically made of polypropylene or polyester, as these materials do not absorb moisture, but allow rainfall and sunlight (the building blocks of healthy plant life) to pass through. Polypropylene and polyester row covers typically last multiple growing seasons. As row covers are generally made by gardeners by hand, the materials used to create them vary widely.
Though polypropylene and polyester are the best choices for protection and allowing rain and sunlight to pass through, gardeners oftentimes don’t have them on hand to use for row covers, which is why you will see makeshift DIY row covers made out of alternative fabrics.
However, polypropylene and polyester fabrics are highly recommended for the job, as many other types of fabric will become too heavy when soaked with water and end up smashing your plants into the ground without support. Even with support, these fabrics will not let in sufficient water or sunlight to perform the job correctly. Also, waterlogged fabrics can easily get mildewed, which can lead to insect infestations and diseases that you are using row covers to avoid in the first place.
Do row covers protect from frost?
Row covers are used primarily to prevent insects from taking a liking to your plant life and deciding to burrow into the soil nearby and feed on your plants. They also serve to fight off disease and keep your plants and soil from overheating.
However, row covers also protect your plants from harsh winds and take a little bit of the edge off of cold fronts. Though the cold protection is minimal, it may be just enough to keep your plants from getting frostbite in the winter, depending on the area you live in and the garden fabric that you use. Row covers give an average of two to four degrees of frost protection in the spring and six to eight degrees of frost protection in the fall, as the soil is warmer in the autumn months.
Can I leave plants covered all day?
Yes, row covers can be placed and left alone for weeks and even months. If you are using heavier fabric exclusively for frost protection, you will want to remove it everyday during daylight hours so that your plants get plenty of sunlight exposure, but if you are using the recommended floating row cover fabrics which allow plenty of sunlight to come through the fabric and shine onto the plants, there is no reason to remove it on a daily basis, as your plants are still getting plenty of sun with it in place.
There are some plants, however, that need exposure to the open air in order for pollination to occur. Vegetable plants that need to produce flowers before they start yielding vegetable crops, require multiple visits from pollinating insects in order to spread pollen from flower to flower. These vegetables include tomatoes, peppers, cucumbers, and squash. With these vegetables, hold off on placing row covers over them until they have finished blooming and have started to produce fruit. Root crops and leafy greens, on the other hand, require no pollination, so they can be housed under covers until they are ready for harvest.
How do you make a garden row cover?
There are many different types of garden row covers that you can make yourself that use a wide range of different materials. Before selecting what type of row covers you want to make, you should select a fabric that suits your needs. Here are a few of our favorite garden fabrics.
All-Purpose Garden Fabric – All-purpose fabric is made from polypropylene and transmits 70 percent of the available light. It works great for keeping bugs out and trapping heat within. It is also a great windbreak for young plants and transplants. It allows plenty of rain and irrigation to reach the soil and plants beneath. All-purpose fabric protects from frost down to 28 degrees Fahrenheit. When not in use, fold and store in a cool, dark, dry location.
Summerweight Fabric – This lightweight garden fabric doesn’t trap a lot of heat inside and is more for defending your crop against insects, birds, wildlife that might attempt to chew up your crops, and the spreading of diseases caused by insect infestations. It transmits around 85 percent of the available sunlight and does not block any rain or irrigation from reaching the plants below it. Summerweight fabric is not for protecting against frost, as it is too lightweight to provide adequate protection.
GardenQuilt – A thicker version of the All-purpose Fabric which transmits only 60 percent of the available light. This fabric is perfect for frost protection, protecting down to 24 degrees F and ideal for extending the growing season into early spring or late autumn, as well as for insulating plants during the winter months.
Shade Netting – Shade netting is designed to cut the summer sun in half, allowing cool air to circulate freely underneath the cover. This is the perfect garden fabric for protecting shade loving plants when you have too much garden space that is exposed to full sunlight.
Once you have picked out the fabric you want to use, there are two main options for constructing row covers. The easiest of the two is to simply drape the fabric over the plants and secure the edges into the soil at the edges of the garden beds. This option is even easier if you use stakes to keep the fabric raised up high enough to keep it from laying across the tops of the plants themselves.
The second option is to pick out a row cover design that you like, buy some materials, and get to building. There are so many options available, you will need to do some research to find the one you want to build. However, many are very similar to the hoop design that is featured in our first link below. So really, if you like the hoop design, you just need to find the tutorial that you like the best. Here are a few of our favorites:
Paper & Pear’s Hoop Row Design – This easy to make hoop style row cover design can be yours for under $100 and will cover three 3×15 foot beds. For full instructions of this design, click here.
Colorful Canary’s Free Hoop Design – If you like the hoop row design, but don’t have a lot of money on hand, check out Colorful Canary’s DIY instructional video for making your own hoop houses for free.
MIGardener’s Low Tunnel for Raised Beds – If you are more of a visual learner, MIGardener does great tutorial videos for gardeners about all types of gardening tasks. In this tutorial, he teaches you how to build a low tunnel row cover for raised beds using half hoops. Each bed can be covered for just under $50 using this design.
What is a floating row cover?
A floating row cover is just another name for row covers, garden fabric, or garden netting. Floating row covers are typically a white, lightweight, non-woven fabric made from polypropylene or polyester.
Row covers are designed to create a shield around your plants to protect them from insects and wildlife, help increase plant growth by raising the temperature and humidity levels within the covered areas, and provide wind and frost protection. Row covers are relatively inexpensive, averaging just 2.5 to 4 cents per square foot, and can be reused for two to three years before needing to be replaced.
Want to learn more about DIY row covers?
Gardener’s Supply Company covers Using Garden Fabric (Row Covers)
Gardener’s Path covers How to Use Floating Row Covers
Gardens Alive covers Using Row Covers Against Insect Pests
Mother Earth News covers Row Covers
Paper & Pear covers Easy and Inexpensive DIY Row Covers
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