After an April marked by snowy mornings and chill winds, spring planting requires an extra shot of courage. Even if you’ve hardened off cold-sensitive transplants such as tomatoes and cucumbers, setting flats outside on sunny days, it will be an act of faith to finally put them in the ground.
Will the weather “have “settled,” as it must for tender crops? Will it ever?
Siting a garden with wind and frost in mind will help conquer spring’s uncertainties. The soil at the foot of a south-facing, heat-absorbing wall is prime real estate, and any piece of ground protected from wind by a fence or hedge is better than one out in the open. Wind does more than just batter plants; it dries them out too.
Sunny enclosures act like sun traps during the day, then reduce radiational cooling at night, when the earth gives back the warmth it absorbs during the day. Most yards have a variety of microclimates from which you can choose, but you can also create them.
One of the many tips found in Thomas Bedford Franklin’s wonderful little 1955 book “Climates in Miniature: A Study of Micro-climate and Environment” is a temporary windbreak made by sticking 2-foot spruce boughs into the ground along the north side of a planting row — thereby gaining 2 or 3 degrees of heat.
Over the years, gardeners have used many tricks to cosset spring plantings. Hilling soil into a ridge running east/west, then planting a row on the south-facing side of the ridge, will boost the temperature a few degrees. Darkening the soil will, too, since a dark surface absorbs heat.
In the old days, people spread soot or charcoal (worth a try, but avoid chemical-laden briquettes). A black plastic sheet, slit with an X at each planting hole, is a modern solution. If your soil is “black gold,” thanks to enrichments with compost and manure, you’re a bit ahead of the game. Protective devices such as cold frames work for small areas and low-growing plants. Floating row covers can be spread over larger beds. Insulators that surround each plant with an upright, water-filled plastic cylinder have been sold in catalogs for years.
Until such companies come out with a gardener’s crystal ball, the thermometer will always give the final go-ahead. For tomato transplants, night temperatures should be at least in the 50s. For direct-sown cucumbers or squash, the soil should be around 70 if possible. And at that point, you will simply decide that spring is here, and get on with it.
Barbara Damrosch’s latest book is “The Four Season Farm Gardener’s Cookbook.”