This year’s vegetable gardening season is about over. The frosts have come and the garden is empty, except for a few things like carrots and leeks, which can be left in the ground and harvested as long as you want.

But if you had planned ahead, you could still be growing a lot of vegetables. A number of tricks can help you extend the season at both ends — getting plants in the ground earlier in the spring and growing vegetables later into the fall.

Frank Wertheim, an extension educator working out of York County, is a fan of floating row covers, or Reemay, a light polyester fabric that can be used in several ways in the garden.

“Floating row covers definitely work well for getting an extra jolt out of any cool-season crop: the radish family, broccoli, greens, lettuce, kale and like that,” Wertheim said. “It can make quite a difference, and it is low-cost. You don’t even need to use the hoops; just lay it right on the plants.”

Some people leave the covers on plants throughout the winter, Wertheim said. If you want extra protection for strawberry beds, the covers can be put on before you put down mulch. And some people in milder climates — in southern Maine and along the coast — could use Reemay alone, without any mulch.

Used early in the season, the floating row covers not only keep the plants warmer so they germinate earlier, but also keep pests from getting at the plants and the tender shoots. Used later in the season, you can toss the covers over warm-weather plants such as peppers and tomatoes to save them from an early frost.

Using plastic provides more heat per layer than Reemay does, but with the plastic you definitely have to use hoops and you have to provide ventilation so the plants don’t get overheated on relatively warm and sunny days.

If you use plastic from hardware or building-supply stores, Wertheim said, you should leave the hoops open at the ends for ventilation. Garden-supply stores sell plastic specifically made for row covers with slits that open when the temperature rises and close when it gets cooler.

For warmer-weather crops like peppers and tomatoes, Wertheim said you can extend the season and have better-tasting crops if you put on Reemay in mid-September, but because those plants do not like the cold weather, you can’t get a lot of season extension past the first frost.

What all gardeners really lust for — whether they admit it or not — is a greenhouse, although they involve a lot of space and quite a bit of money. But a lot of commercial growers, inspired by Eliot Coleman, are harvesting greens all winter long by using unheated greenhouses coupled with the extra protection of row covers.

“You won’t get a lot of growth in winter because the sun is so low and there is not enough day length,” Wertheim said. “What happens is that the winter greens just kind of sit there, staying alive so you can harvest. With that, you can certainly make a greenhouse pay for itself over time.”

But for this to work, you have to plant the greens early enough in the fall so they are a fairly good size going into the cold period of winter.

After talking to Wertheim, I went to the Johnny’s Selected Seeds website, www.johnnyseeds.com, and found five tips for extending the season. They were planting greens in a high tunnel in February, seeding leeks in a greenhouse or cold frame in February, having row cover ready in case of early frosts, planting spinach or carrots in a hoop house to harvest all year and overwintering spinach in low tunnels. So check that out if you want more information.

Tom Atwell can be contacted at 791-6362 or at: tatwell@pressherald.com