“It was such a pleasure to sink one’s hands into the warm earth, to feel at one’s fingertips the possibilities of the new season.”
~ Kate Morton
You might think of the growing season as the time between spring’s last frost and autumn’s first frost, but all vegetable gardening doesn’t wait for warm weather to be in the forecast. Cool season vegetables are hardier varieties that tolerate — and even thrive — in the cold soil of early spring.
When Can You Plant?
What’s really important is soil temperature — it must be in the 40°F range for cool season vegetable seeds to germinate. Simply go by the general rule that soil is warm enough when you can easily turn it with a shovel.
What Can You Plant?
Cool-season crops include the salad vegetables: lettuces, kales, chard, onions, peas, and radishes. Everything in the cabbage family (cabbage, broccoli, cauliflower) also grows well in the cool spring air. In fact, their flavor often depend on harvesting before the heat of summer sets in.
To get the most vegetables throughout the year, plan for two “shoulder” seasons of cool-season crops. Plant spring vegetables in April, then follow with warm-season veggies like tomatoes, peppers, and corn in the summer. Then you can plan on planting a second crop of cool-season vegetables in the autumn after the weather cools down.
For your cool-season beds, choose a well-drained spot that gets as much sun as possible. Add some organic matter such as compost or sphagnum peat moss and spade or till it into the soil. You can water less frequently in the cooler seasons since plants will dry slower in cooler temperatures.
Making the Transition from Greenhouse to Garden
Many bare-root vegetables and cool-season crops can make the transition into the outdoor garden — but only after going through a process known as hardening off. This process reduces stress and is essential to the success of your tender plants.
Plants that start life in a greenhouse or under lights in your home spend their time in pampered comfort. The temperature is perfect, the wind doesn’t’ blow, water is always gently and carefully applied, the sun never scorches, and rain never pounds. To prepare them for the harsher realities of life outdoors, they’ll need to gradually acclimate.
For one to two weeks, move the plants outside during the day while temperatures are warm. Then bring them back inside at night when the temperatures chill down. Place them in an area that’s protected from sun and wind. The third week, as long as night temperatures aren’t going to drop below freezing, you can leave the plants in a protected area overnight. After this adjustment period, you should be able to safely leave your plants outside for the season.
Always be Prepared for Frosts
Most cool-weather vegetables can tolerate a light frost, but you’ll want to keep the frost cloths handy for sudden cold snaps and those inconvenient late-spring and early autumn frosts.
You can also protect planted veggies with a Season Starter. These transparent “walls of water” are simple solar shelters that allow the soil to warm to a temperature suitable for plant growth.
Keep the Harvest Going
You can keep the supply of spring veggies going with succession planting. Plant your fast-growing crops in two-week intervals to prolong the availability of lettuce, spinach, peas, and radishes. When the weather gets too warm for these vegetables, you can plant more of them in the shade of taller plants like pole beans and corn. This system is also good for gardeners with limited space.
Growing your own food has always been one of the healthiest (and tastiest!) ways to feed your family. If you can’t wait to get your hands dirty in the garden, give cool-season crops a try!