Q: I am concerned about that last frost hitting my newly planted vegetables. How can I protect them from potential frost, but not overheat them on warm days? —M. K., Whately
A: May is always a bit quirky around here, M.K., so your question is a wise one. It is a month of transition from frost potential to frost-free temperatures and we are all just aching to plant everything right this second. Thankfully, there is a product designed to address just this issue — floating row covers.
Floating row covers are made of light, airy spun plastic such as polypropylene or polyester. They are white in color with a texture similar to tissue paper. When you ask for them at the garden center, you may need to call them all-purpose garden fabric. Super lightweight, they seem to float above the ground, hence the name. Their permeability allows sunlight, water, and air to flow through the material. These covers come in different weights, but the most common one is the medium weight version (0.50-0.55 oz/sq yd) as it protects plants from light frost (down to 28 degrees F) and allows close to 85 percent of sunlight to pass through, which is enough to both support plant growth and enable cool spring soil to warm. As a physical barrier, it also helps protect plants from unwanted insects and birds.
To use them, first determine the length and width you need. When measuring, be sure to account for these three considerations: 1) Have enough material to completely cover your crop on all sides. If you are using hoops, remember to account for their added height, 2) Allow extra room for plant growth, and 3) Allow enough extra material to secure edges with soil, rocks, landscape staples, or other heavy objects so the covers do not literally float away. For example, a 6-foot wide roll can cover a 3-foot wide row and allow room for your young plants to grow upright while well secured.
Floating row covers are easily cut with scissors to adjust to your particular row structure. Once you determine your needed size, simply cut the fabric and then gently drape the cover directly over the plants or elevate it using hoops, securing it when done. That’s it!
Are you growing insect-pollinated crops such as squash, cucumbers, or melons? If so, remember to remove the row covers when the plants are in bloom.
To best protect against pest insects, install the cover before they are evident. Periodically check under the row cover for insects. Remove and discard any infested plant material.
If handled carefully, floating row covers can provide several years of use. Since soil particles can tear the material, hose down dirty covers with water. Let them fully dry, then store them away for the next time.
Good job planning ahead, M.K. Thanks for asking a (local) master gardener.
Have a gardening dilemma? Please send questions, along with your name/initials and community, to the Western Massachusetts Master Gardener Association at AskAMasterGardener@wmmga.org. One question will be answered per week. wmmga.org