Frost Protection
When we have warm spring weather it can be difficult to not just go out and plant everything! Traditionally there is still a good possibility of frost in the Connecticut River valley through May 20, and up in the hills through Memorial Day weekend or even the first week of June.
Watch those potted tender annual flowers, potted seedlings, herbs, and houseplants. It’s best to bring these guys in if the nights drop below 40 degrees. If it’s just for one night, cover them with floating row covers, a bed sheet, or thicker blanket that won’t damage the plants but will keep the frost off. For more than one night, you’d be asking for trouble by leaving them outside.
With proper cover, such as floating row covers, you can get a head start on seeding some crops like peas, lettuce, mustards, and arugula. Crops that get buried like onions and potatoes will also be okay in normal cool May temperatures but do keep them covered as their tender greens are susceptible below 32 degrees.
You can seed or transplant members of the brassica family (broccoli, cabbage, collard greens, brussels sprouts, kohlrabi, and kale) outside now but they may need a little extra protection on the colder nights.
If you are one of the eager ones and just have to get out there early no matter the weather, try this trick: cut out the bottom of a gallon milk jug and place over your new transplant, burying the bottom of the jug in to the soil an inch or so deep. This protection will prevent sun, wind, or frost damage to tender transplants. Remember to remove the jugs when you water the plants, or water each one through the whole on top of the jug. Once the weather warms, you can remove the jugs and reuse them next year.
If you are buying transplants from a greenhouse, be sure to harden off your plants first so they don’t get sun or wind burn when you put them out in the exposed garden.
Interested in learning more? The Grower’s Library at Johnny’s Selected Seeds may have the information you’re looking for.