Hard freeze alert tonight: Protect your plants

Most of the Tucson area will see lows near or below 28 degrees, the National Weather Service in Tucson says. Keep in mind that you’re even more likely to get freeze damage if you live near a wash.

Even colder temperatures will be seen in the valleys of Cochise, Santa Cruz, Graham and Greenlee counties. Overnight lows there could be in the low to mid-teens.

What can gardeners do to protect their plants?

Truth is, there’s only so much you can do — established trees or cold-hardy plants can usually tough it out. But you can take some steps to protect young veggies and citrus trees.

General tips:

• Don’t use plastic to cover plants; use old bed sheets or frost cloths, available at nurseries and big box stores. Frost cloths can be left on for two to three weeks, says Tony Sarah, the general manager at Magic Garden Nursery on the east side. Indeed, an even bigger cold front is heading our way next week, Sarah says.
• Try to keep the cloth off the leaves.

Tips for veggies:

• Cover or harvest lettuce — it should survive a hard freeze but can turn bitter.
• Cover young seedlings, which are sensitive to frost.
• Cover peas if they’re flowering.
• Established broccoli, cabbage and other brassicas will be fine. In fact, cold weather will improve their flavor, Sarah says.
• If you're lucky enough to have any peppers or green tomatoes remaining in the garden, pick them now. The tomatoes will slowly ripen indoors, or you can make fried green tomatoes with fresh cornmeal. Sarah says it would take “major effort” to save those summer veggies.
• If you have any starts outside, bring them in. (I have lettuce, broccoli and other veggie starts in flats and have been bringing them inside every night.)
• If any leaves are frozen tomorrow, don’t disturb the foliage, Sarah says.

Frost-sensitive trees such as citrus:

• Water deeply tonight. We didn’t get much rain last night, so Sarah suggests watering them for four to five hours.
• Harvest oranges, limes and lemons if ripe. Whether to harvest them now is a judgment call, Sarah says. They might not be ripe yet but this hard freeze could decimate the fruit.
• Wrap trunks with old-fashioned Christmas lights before covering.
• Or use an incandescent or halogen light bulb under the tree if you have access to electricity and toss a sheet or frost cloth over it.
• Otherwise, just cover it and hope for the best.

Cactus and succulents:

• Don’t water.
• Cover young or newly transplanted cacti.
• Put a plastic foam cup over the tips.
• Wrap sensitive cactus such as totem poles or fence posts in newspaper.

Special thanks to Tony Sarah of Magic Garden Nursery