Never has a garden gadget been as valuable as row cover in this cool, showery spring. This light, synthetic fabric does a fabulous job of protecting young plants from early season cold, something we’re experiencing on a regular basis right now! Row cover can provide several degrees of additional warmth by trapping heat under the filmy, opaque white fabric. This improves seed germination and accelerates plant growth during those critical early days in the vegetable garden when you often cross your fingers and toes and hope that the weather gods are smiling on your little pea patch.
While the material is opaque it still allows up to 85% of available light to pass through, meaning that plants can continue to grow underneath these wispy white blankets. Water can easily pass through the material as well so you don’t need to remove the cover to irrigate, although that hasn’t been an issue this spring.
The extra heat produced under row covers allows biology to occur much faster versus plants without protection. Corn that is two inches high will be four inches high when grown under cover as the cells will divide faster. Slow maturing plants like melons will ripen faster, you can warm up soil for crops like cucumbers and beans that don’t germinate well in cooler soils. In the fall heat trapped by row covers will keep cold temperatures from damaging late ripening tomatoes or peppers. Just as clouds keep radiant heat from escaping into the atmosphere row covers trap warmth built up in the plants and soil during warm fall days.
Insect prevention is an added bonus. The physical cloth barrier provides a break from insects because they can’t get to the plants to feed, lay eggs or otherwise destroy your precious seedlings. In my garden the raised bed that is filled with salad greens is fitted with row cover clipped onto arching PVC pipes to form a mini-greenhouse effect. I’m not keeping the insects away; it’s to keep the quail from helping themselves!