Ask a Master Gardener: Consider row covers when growing zucchini

I know this will sound strange, but recently I have had several people requesting information on growing zucchini. Seems the one-time prolific vegetable has become a little harder to grow. This may not be the case for you, but some gardeners are having trouble keeping the plants alive.

One of the first things I recommend are row covers, and that is not just for zucchini. Row covers, especially floating row covers, can be used for a variety of purposes.

They are not the prettiest to look at, but floating row covers are great when it comes to protecting your tender vegetables from early frosts and, in the cases like zucchini, hungry pests.

Most row covers are garden fabric made of polypropylene, which not only protects plants from frost damage (down to 28 degrees F) but also allows light through, traps heat in, keeps bugs out and is an excellent windbreak. It also allows rain and overhead irrigation to reach plants and soil.

Row covers are used primarily for two purposes: to provide protection from pests and cold weather. The are called floating because the material is so light you can simply put it on top of the plants and secure the edges with soil or something heavy. No additional support is needed in this case. Lightweight covers like these are used mostly for protection from harmful pests, like flea beetles and cabbage looper moths attempting to lay eggs on the plants. Row covers will also protect your squash from cucumber beetles that carry bacterial wilt.

There are several type of row covers. For frost protection, look for the heavyweight row covers. They let in less light but trap heat, raising the temperature under the cover a few degrees, often enough to make the difference between life and death for tender plants. Don't use a heavy cover after the weather has warmed or you run the risk of cooking your plants. These heavier covers often need some sort of support, often in the form of a "hoop."

Lightweight row covers are best for insect control, letting in 80-90 percent of the light and not overheating or blocking rain. However, they're not enough for frost protection.

Applied early enough, they will keep flea beetles from eating holes in your lettuce. They are great for blocking flying insects such as Japanese beetles, potato bugs, bean beetles, grasshoppers, cucumber beetles, squash vine borer moths, root maggot flies and cabbage moths.

They are not as effective on slugs, cutworms or insects that emerge from the soil so you will have to keep an eye on your plants for damage from them. If you are protecting plants such as cucumbers and squash that need pollinating to produce fruit, be sure to remove the covers once the plants start blossoming to let pollinators in. By that time, the plants are usually large and strong enough to survive insect attack.

Row covers will also help protect your newly planted seeds from birds. Of course, they will discourage deer and rabbits, although the squirrels would probably figure out a way to get in them.

Laying a row cover over the newly planted beds helps to keep moisture from evaporating too quickly and prevents the soil from crusting over. The emerging seedlings will lift the cover as they germinate. This can be especially helpful for small seeds like carrots.

Even if you are not having trouble growing zucchini, row covers are a handy tool to have in the garden shed.

Happy gardening!

Peter Sutter is a life long gardening enthusiast and a participant in the MU Extension's Callaway County Master Gardener program. Gardening questions can be sent to [email protected].