How to Warm the Soil in Your Vegetable Garden

When you live in a high desert climate like I do, growing a bumper harvest of produce vegetable is a challenge. Along with minimal rainfall and a short growing season, our cool spring temperatures means that vegetable seeds are slow to germinate and slow to grow.

Warming up ground temperatures is an easy way to get a jump on gardening. Here's several of the different methods I use to warm up the ground and keep it warm for my early spring and late fall vegetables.

Plant close to a south facing wall. All yards have "hot spots," south or southwest facing areas that capture solar heat and warm the ground. In my yard, the hot spots are on the south side of both my garage and a west-to-east cedar fence line.

These warmer areas are ideal for planting early spring crops such as peas, spinach, and salad greens. It's been my experience that spring seeds planted in the "hot spots" germinate about two weeks faster, grow faster, and are faster to produce vegetables than seeds planted elsewhere.

Use visqueen. Black plastic, known as "visqueen" keeps down the weeds and helps warm up the soil beneath. Visqueen works especially well with squashes and melons which require soil temperatures of 60 degrees or higher before the plants really start to grow.

Place bottles around heat loving plants. This eco friendly and simple idea upcycles old wine bottles into solar collectors for the garden. While bottles are far too hot for summer use, they work well in the spring and late fall.

Use mulch. Grass clippings generate heat as they decompose. I'll surround my spring seedlings with a 2-3" layer of grass clippings which keeps down the weeds, slows down water evaporation, and warms up the ground.

Recycle those old aluminum windows. Have you recently upgraded the windows in your home? Old windows are fantastic solar collectors and do a great job of warming up garden beds. Some of the more interesting ways I've seen old windows used is as lids for garden boxes. I'm lazy however, and angle them instead against the fence to create a lean-to greenhouse. This simple but effective way of warming the ground extends my growing season by 2-3 weeks.