Gardening During Unpredictable Seasons

  • Difficulty Rating: Beginner
Gardening season predictions that are unpredictable

May is here, with birdsong and blue skies, and most gardeners can now forget about frosts.

But the weather and the calendar do not always agree, as I learned — yet again — last May, when a late snowfall and a stretch of surprisingly cold days put the brakes on the gardening season just as gardeners were getting warmed up.

Seeds just sprouting from the earth

Gardening teaches you to become aware of the subtleties of your climate. Good garden notes, a calendar, and the USDA Hardiness Zone map give you a pretty good idea of what to expect in your garden every year, but nothing beats flexibility. In Kansas City, where I live, the typical growing season is about 200 days long, from early April through late October. Beginning in mid-March, gardeners launch the season, planting shrubs, perennials, and cool-season crops, but conditions are still very tricky. Spring temperatures swing like a pendulum: one day you’re scraping ice off the windshield and the next you’re wondering if there is still time to plant peas before summer’s heat sets in.

Frost-free dates, like a zone map, are just another way to arm yourself with information. Several web sites (including this one), will show you both, so you can compare the length of the gardening seasons in different areas. The growing-season calculator on the website of the Old Farmer’s Almanac even does the math for you, and tells you just how many days there are in your growing season, based on your ZIP code.

Snow on the grape hyacinths

These maps and charts rely on averages. The Farmer’s Almanac says its dates are based on the normal average date for the last spring frost and the first frost in the fall, which means you have to allow for a 50 percent chance that there could be another freeze (29 to 32 degrees) on either side of those terminal frost dates. You also have to remember that, despite occasional crazy temperature swings, the soil temperature normally makes a gradual transition between seasons. On a mild day in May, you may be in shirtsleeves, but the soil temperature may not yet be warm enough to transplant tomatoes, or to plant the seeds of annual cosmos and zinnias.

Tomato in the garden

Browsing through a seed catalog will tell you why frost dates and zone maps are important. If you’re interested in growing heirloom tomatoes, for example, you’ll discover that most of them need a good 80 or even 90 days in the garden to mature. This is no problem where the gardening season is long and hot, but for gardeners in Green Bay, Wisconsin (and other areas with short, cool summers), tomatoes hybridized for cooler temperatures and a shorter growing season will be a better choice.

Trimming the vinca with hedge shears

The spring is in any case a wonderful time to be in the garden: there’s a lot to do while you’re waiting to plant. A few minutes with a rake works wonders, both in your garden and in your spirits. When it’s still too cool to dig, I pick up my fancy Fiskars® PowerGear® hedge shears and cut off the winter-burned leaves on the variegated vinca along the low porch wall. I almost always have pruning shears in my pocket, and one of the things I do at this season is clip last year’s dried-out flowers off the hydrangeas.

It can be fun to take chances with the seasons, but patience is usually the wiser counsel. If I feel like gambling, I might make room for a few lettuce plants in the planter boxes on the front porch. We still might get a frost, of course, but my gardener’s instincts — which are only wrong half the time — tell me we might not, too.