It comes entirely too soon for most Colorado gardeners: Time to bring those tomatoes inside or tell ’em goodbye.
Whether or not the mercury actually touches the freezing mark tonight or Friday night, temperatures in the 30s and 40s will meaning unless your plant has several layers of frost protection and preferably some artificial heat, those precious love apples you pampered all summer are done gaining in sweetness.
Get out there and harvest, but don’t despair: Many other crops will survive with a light covering or even thrive.
This afternoon, hourly forecasts for Denver from weather.com were a low of 33 in the wee hours of Friday. Forecast for the wee hours of Saturday wasn’t much warmer, and if you live in the foothills or garden in a low-lying area, it will get colder there.
Here’s what to do tonight for what you grow, according to Colorado State University Extension, and horticulture director at the Denver Botanic Gardens.
• Tomatoes: If it’s full size and has even a hint of red, grab it. Also pick fruit that is glossy-green and at least three-fourths its mature size. CSU Extension has a detailed fact sheet on at . If your prize heirloom variety is bedecked with fruit, dig up the whole plant and bring it into your garage to hang upside down. And don’t despair: cooks have ways with green tomatoes, If you want to cover the plants to hope for more days of outdoor ripening, use a polyspun row cover or cloth sheets, then cover with plastic to keep the rain (or snow) off. Don’t let plastic touch the plants, but bring it all the way down to the ground and weight or pin it there. The same treatment can work for strawberries. But most important of all: Don’t forget to remove covers when weather warms up, and put covers back on when it’s below 50.
• Eggplant, peppers: If it’s mature, pick it. Cover any plants with immature fruit if you can, again with cloth, then plastic. Krishnan said. Don’t forget that container plants can come indoors for the night.
• Cucumber, summer squash, beans: Pick the mature fruits. Their season was nearly done anyway.
• Potatoes, carrots, beets, radishes, turnips: These are under the soil, which will stay warmer than the air.
• Sage, rosemary, thyme, parsley, other salad herbs: You don’t even need to cover them. If they’re in containers and you’re a worrier, go ahead and bring them inside. But basil? Unless you’ve got a hoop system and at least 4-mm-thick plastic, cut it and make pesto.
• Cabbages, other cole crops, kale, broccoli raab, lettuces, spinach: Cabbage will be fine; kale and carrots will get sweeter. Tender lettuces and spinach might like to be covered.
• Roses and other perennials, pansies and mums: If they’re new plantings, cover them, says Cahill; if established, no worries other than snow in the foothills, which might batter the flowers.
• The upside: The moisture is good! Lawns, trees, shrubs will love it. But the chill won’t affect most insects, Krishnan said.
