by Carol Dunn
HUERFANO– There is no substitute for the taste of a fresh, garden-grown tomato, but few vegetables can be as frustrating to raise at high altitude. If nighttime temperatures go below 50 degrees on our green tomatoes, they will not ripen on the plant. So our mission as tomato gardeners is to keep the temperature of the air around our tomato plants warm, day and night.
If you have tomato seedlings, you’re ready to plant them out. I like to wait until after June 8, the latest frost date I’ve experienced since moving here. You’ll still have wind and hail to contend with, but the hard frosts are probably past. Buy short season tomato plants, Siberian if you can find them; they are some of the best for growing at high altitudes.
Choose a warm microclimate for growing tomatoes. The ideal spot will absorb the heat of the sun during the day and release it at night, for instance next to a masonry wall, your house foundation, a pile of rocks, or even a stack of old tires. Because of potential soil viruses, do not plant tomatoes in the same location more than once every four years.
After planting, cover your plants with a tiny greenhouse made from a milk jug with the bottom cut out. Leave off the cap so your plants don’t cook. This greenhouse will give your plants a big boost in growth. Once they’ve outgrown the milk jug, you can continue providing nighttime warmth by creating your own version of a “wall-of-water.” Fill gallon milk jugs with water and surround the tomato plant with them.
If you don’t have a good microclimate location, you can create one by building an “open top greenhouse” for each tomato plant. Build a frame from 2x2s or even scrap lumber with dimensions from 2 ½ to 3 feet square, depending on the estimated mature size of your tomato variety. The frame should be 2-4 feet tall – taller gives better wind protection – with feet to seat into the soil. Wrap the sides of the frame with plastic sheeting. Use plain white bed sheets to cover the tents at night.
One grower suggests using the heat of decomposition. Dig a hole two feet deep, put a few inches of relatively fresh cow manure in it, fill in the hole with soil, then plant your tomato plant as you normally would. The decomposing manure creates heat, which will warm the tomato plant from below.
As with any cultivated plant in this dry, windy climate: mulch, mulch, mulch. A couple inches of mulch around each plant will hold in moisture and inhibit weed growth.
Next week we’ll look at fertilizing and companion planting. If you have any tips, please email them to: ssimons@wildblue.net.
