Get Your Garden Growing Early

Enlarge Image Image Gallery Cloches, or gardening bells, can be used to protect individual plants. iStockphoto.com/Brett Charlton

SIDEBAR
Garden Tools to Extend the Season

After struggling through a winter of grocery store greens and frozen produce, I don’t want to wait until June to enjoy fresh vegetables. Just because there might be snow on the ground doesn’t mean planting has to wait for months.

Nearly two decades ago, I moved from Ohio to Montana and quickly learned that, if I wanted fresh food before the middle of summer, I had to rethink my gardening techniques. The hallowed “last frost date” became a guide, not a law.

From the ground up

When the ground is frozen, even the hardiest seed won’t do a thing. If it’s cold and wet, the seed might even rot before it ever has a chance to grow. The key to germination is to plant seed in soil that’s warmed to 65-75 degrees. But in the frozen North, how do you get that soil warm enough, early enough? One easy method is to spread clear plastic over the soil, burying the edges to keep it in place and lock in the heat. Even if daytime temperatures hover in the 40s, the sun’s energy can heat the soil beneath the plastic to a whopping 125 degrees. Keep the plastic in place until you’re ready to plant. If your early season garden plot is a raised bed, so much the better. Soil in a plastic covered, raised bed will warm faster. 

When growing heat-loving crops such as melons, peppers and cucumbers, it’s especially important to pre-warm the soil. Transplanting these crops through black plastic, which will keep the weeds down and the soil temperature up, helps ensure success in the north.

When you don’t have a greenhouse

Many gardeners dream of a permanent greenhouse; they take up valuable space in the yard and can be expensive. But most of us can find an area for at least one cold frame. This structure can be a simple, bottomless wooden box built with an angled, window-like top to gather the sun’s energy. Many cold frames are painted dark green, black or brown to absorb solar heat. Before planting inside a cold frame, keep the lid closed for several weeks to warm the soil.

A reasonable cold frame size is 3 by 4 feet, which is easy for one person to move, although permanent frames can be much larger. Just be sure you can reach the internal growing spaces without the need to climb inside.

When I’m really organized, I plant lettuce, spinach or mâche (an old European winter favorite) in August, and set the cold frame over the plants when the weather begins to freeze. It’s a bit of a challenge in early fall when daytime temperatures are warm because you will need to open and close the lid for temperature control. But once the cold weather sets in, I keep the lid closed, which keeps the plants growing into early winter.