A growing season is typically defined as the period between the last frost in the spring and the first frost in the fall.
What does this actually mean for gardeners? Here are two things to know about “growing season.”
First, there are cool season and warm season vegetables.
Plants like lettuce and peas prefer it cool. Some cool season vegetables such as Brussels sprouts and collard greens can even take a nipping of frost without harm. They tend to bolt, or go to seed, when the weather gets too warm, effectively stopping production too soon.
Other plants like it warm. If the weather is too cool, they’ll just sit there and sulk. And if the temperature drops to freezing, they’ll quickly die. But there’s a balance here. Vegetables from tropical areas, like black-eyed peas, okra and sweet potatoes, will bloom and mature veggies for you even when it’s 100 degrees outside. On the other hand, tomatoes and squash are finicky. If the weather is too hot, especially at night, they will quit blooming and stop setting fruit.
The second thing to understand is long season and short season.
In a temperate climate like the United States, this growing season can vary a lot. In Maine, the growing season can be as short as 90 days, while in south Florida, gardeners enjoy a year-round growing season. Put in a plant whose length to maturity doesn’t fit the season your climate offers, and your garden’s doomed to failure.
So how do you get the right plants in your garden at the right time? Agronomists, plant breeders and other scientists have some great solutions for us.
For one thing, you can adjust the climate. For cool weather plants, even without a greenhouse or cold frame winter can be part of your growing season. Use frost blankets, row covers, glass cloches and other devices to trick the season. You keep plants from freezing by providing a slightly warmer microclimate. This microclimate is created by capturing heat from the soil and the sun’s rays and preventing its release.
The “wall o’ water” product that appeared in the 1980’s took this one step further by applying physics. A series of plastic cylinders filled with water surrounded the plant. As the water froze, it would give off heat, generating a protective microclimate even with the device open to the cold at the top.
For warm weather plants, you can experiment with controlling the upper temperature. Moving plants into the shade if you are using containers, or covering them with shade cloth, a dark fabric that limits light and heat, can reduce the temperature that plants experience during the hottest part of the day.
The second approach is to change your definition of growing season.
Be realistic about how your climate behaves. Start with the garden catalogs, even if you plan to buy plants. Most catalogs are online these days, making plant review simple. The catalogs will tell you something vital – the length of time to maturity for each variety of the plants you want to grow.
In central Texas, for example, our growing season is typically said to be mid-March (last frost) to mid-November (first frost), which is considered a long season. Gardeners know, however, that heat can set in as soon as mid-May, stopping the fruit set for tomatoes and making snow peas wither on their trellises.
For success here, you may need to think of the climate as a series of short seasons, rather than one long season.
For the cool season, look at the catalogs from places like Vermont and Oregon, and find the offerings with the shortest time to maturity. This can help you beat the spring heat and speed the time to harvest.
For summer, again look for short season plants that can mature, set fruit and be finished before the afternoon heat hits the century mark. And, look for plants and seeds from southern breeders, who are starting to succeed with plants that produce even when it’s hot and humid at night.
And if you are gardening in Alaska, you may actually have a long season because those almost-24-hour days of sunlight in summer extend your season, from a plant’s perspective.