Today’s post can be heard on the public radio show Crop to Cuisine, hosted by Dov Hirsch.
You can tell who the serious vegetable gardeners are. They’re the people who construct the darnedest coverings to provide a few extra weeks worth of growth before the weather really warms. Gardens start to look like a rock festival with all of the tents, tunnels, and jugs showing up.
One gardener in Lockport, Illinois, a town just outside of Joliet, sent me photos of the prettiest seedlings I’ve ever seen grown at home. Despite living in zone 5, he planted these out on April 13, a full month-and-a-half ahead of when we – also zone fiveish – put ours in the ground.
Now, I’m not what you would call a competitive gardener – if others like to get their gardens in fast, that’s up to them. But looking at the deep green, foot-tall plants this 74-year old gardener’s got in the ground made me pause in envy, and think “when I grow up, I want to be just like Jim Koski.”
As we head into May and you’re shopping for that special seedling, take a page from his book to keep your plants cozy in our unsettled weather, at least through frost date. Jim tucked his into the ground with a combination of items; his objective is to warm the soil with sun in the day and give plants frost protection at night.
With a red plastic Automator tray – the product touted for channeling water and fertilizer to roots – to warm the soil, Jim breaks wind on his seedlings by wrapping their cages in stiff, black salt paper. Chill breezes are a seedling’s enemy, but this method keeps his plants “nice and toasty.”
I’ve seen many types of protective covers; a friend of mine firmly believes that Christmas lights hung inside a plastic tunnel are the best means of protecting plants from late frosts. This makes sense to me. By using one 25-light string of mid-size, non-LED (C-7) Christmas lights per four-foot-by-five-foot tunnel, gardeners can give an additional 6 to 18 degrees F◦ of warmth to plants and add that festive touch to a spring landscape.
Constructing the tunnel isn’t difficult. Space sturdy wire hoops at 3 to 5 foot intervals or closer if the location is windy. The hoops hold a cover of six-ml or thicker plastic that forms a tunnel along the bed. Weigh down the edges of the plastic by burying it a few inches into the soil on all sides, or staple the plastic to the sides of a raised bed box. Be certain to allow some ventilation with small, two-inch holes along the lower sides, or make a strip along the top that can be opened and closed. To avoid overheating the seedlings, open the vents on warm days, but leave them shut on cloudy, cool days.
String the lights from the hoops to allow them to dangle slightly into the tunnel. Use an outdoor-approved extension cord to run electricity to them, and you’ll have tomatoes to brag about weeks earlier than your neighbors (but most neighbors will take one look at those Christmas lights and assume you’re crazy, so won’t argue over whose tomato was ripe first anyway).
The most common frost protection is water walls, a tee-pee like ring of plastic tubes filled with water surrounding the plant. This works on the principle of heat release when water changes from liquid to ice and can protect down to mid-teen temperatures. They’re helpful if you want to put your tomatoes, peppers, or eggplant into the ground before the end of the month, when the weather settles into warmth.
The trick to using the water walls is to pick a warm day, plant the seedling, position the water wall and fill it. I find that using a watering can with a narrow spout helps to control the water when pouring into the tubes, or a hose end hand sprayer works well if the water pressure isn’t too high.
Give your seedlings a shot of starter fertilizer, or try Jim’s technique of spraying the plants with organic fertilizer. He uses dilute fish emulsion or Sea Magic, a seaweed extract mixed into water, then spritzed on the leaves of the plants. Your plants will be catching up to his, in no time.