Hard Freeze in the Forecast? Here's What To Do, Before and After

Frost, Freeze, Hard Freeze: Yes, they are all words that can make you shiver. But for gardeners, the preparation level in the yard goes from not stepping on the lawn in the morning (grass blades can break under your weight, even during a light frost) to madly rushing around the premises to protect plants, pets, and water lines when a hard freeze is forecast.

 First, some widely accepted definitions of those terms:

Frost: temperatures dip to 32 °F (0 °C) for short periods of time. Occurs with fair skies and light winds.

Freeze: temperatures at or below 32 °F

Hard Freeze: temperatures below 28 °F for several hours.

In the Sacramento area, the typical frost/freeze season is from late November to early February. However, frosts have been recorded as early as the first week of November and as late as the last week of March.
 
Here's a last minute checklist for your home and garden if the TV weather people (or panicky bloggers) tell you the morning low will be in the mid-20's, for several hours:
• If it hasn't rained, water plants thoroughly, especially container plants.
 
• If possible, move sensitive container plants next to a south or west facing wall.
 

Agribon Frost Cloth Protecting Meyer Lemon Tree

• Cover citrus and other sensitive plants with burlap, row cover fabric (such as Agribon) or sheets (be sure to keep the sheets dry). Tent plastic sheets over the plants; don't let plastic touch plant leaves. A light bulb placed in such a plant can offer a few degrees of protection. For best protection, sheets should reach all the way to the ground around citrus trees and other freeze-susceptible plants.
 
• If using an anti-transpirant polymer coating material such as Wilt-Pruf or Cloud Cover, apply at the warmest time of the day, or at least six hours before an expected frost. Read and follow all label directions. If using these products, thoroughly water the plant before applying.
 
• Disconnect hoses and drip lines, removing end caps. Lay out straight.
 
• To prevent broken grass blades, don't walk on a frozen lawn.
 
• Remove the lowest sprinkler head to drain.

Protect exposed pipes around wells and pumps

  



• Cover unprotected faucets and pipes, including any spa or pool equipment.



 
 







• To prevent frozen attic pipes, let lukewarm water trickle out of the indoor faucet farthest from the inlet. Also, let faucets with pipes running along an outer, north facing wall trickle during the night.  
 
• Open cabinet doors to get more heat to the pipes. Close the garage door if water pipes pass through the garage.
 
• Setting your thermostat nightly at 55 can add needed heat to the attic pipes.
 
• If leaving the house for a vacation during an expected freeze, turn off the water to the house, and open up the faucet farthest from the inlet. Be sure to turn off your water heater.
 
• To prevent cracking tile, run your pool and spa equipment during the freezing hours. 
 
• Don't forget about your pets during a prolonged freeze. Bring them indoors at night. Move or replace their drinking water. Break up any frozen water in bird baths. 


 




• Cover the worm bin, too!














After a hard freeze, panicky gardeners should fight the urge to clean up the garden. The best strategies after a hard freeze? 
• Make sure all plants, especially container plants that are protected by overhangs, have been irrigated. Moist soil can protect the roots of suffering plants better than dry soil if more cold snaps hit. 
• Don't prune away any damaged portions of plants.

If plants in your garden look blackened and wilted now, new growth may emanate from the base of the plant when the weather warms up in a couple of months.
 
Pruning away the dead portions now exposes buds that may still be alive; another frosty morning could wipe out those survivors.

The average frost season for Sacramento is about two months, primarily December and January. But temperatures below 32 have been recorded as early as the first week in November; as late as the third week in March.

So, keep the shears in the garage and let the dead portions of the plants protect the understory. 

It may take until mid-Spring before you see new growth. Patience is key before you pick up the pruners. In the meantime, tolerate the ugly.

Make sure your garden and potted plants remain moist, especially if it isn't raining. Water gives off heat, and this can protect plants from freezing, especially borderline citrus trees, such as lemons and limes. Damp soil retains heat better than dry soil, protecting roots and warming the air near the soil.

Some of those dead plants may be summer annuals. Say goodbye to the tomatoes, impatiens, marigolds, squash, and others. Mornings hovering around 25 degrees can do that to these summer annuals. Put them in the compost pile; purchase and plant more in the spring, after all danger of frost.