Sacramento Digs Gardening logo
Sacramento Digs Gardening Article
Your resource for Sacramento-area gardening news, tips and events

Articles Recipe Index Keyword Index Calendar Twitter Facebook Instagram About Us Contact Us

For cold nights ahead, here's a frost plan

Old-style Christmas lights can help protect a frost-sensitive tree, such as this container citrus in a display at the Fair Oaks Horticulture Center in October. (Photos: Kathy Morrison)

What to do when temperatures dip below freezing

Monday's chilly morning was a brisk reminder: We're now in frost season.

According to the Old Farmer’s Almanac, Sacramento's greatest frost danger falls between Dec. 4 and Feb. 10. While most of our outdoor plants can survive brief periods at 32 degrees, it's when overnight temperatures dip into the 20s for an hour or more that's particularly destructive. That's cold enough to turn stored water in stems and leaves or juice in fruit to ice. It can reduce a begonia into mush or burst ripe oranges.

Be prepared for more cold nights ahead with a frost plan:
* Know which plants are most at risk: Succulents, ferns, tropical plants, citrus, avocados, cacti, begonias, geraniums, peppers and soft-stemmed perennials. Mark those plants that need frost protection with a visual cue such as a blue-painted plant marker as a reminder.
* It's usually warmer close to the house. Move container plants under the eaves and create a frost-cloth tent. Suspend frost cloth or cloth sheeting from the rain gutters with clothes pins, then anchor it to the ground. Tuck in plants before sunset and remove the tent during the day.
The frost display at the Horticulture Center also included a frost blanket,
which should be pulled  completely over the plant when in actual use.
* Have on hand lightweight cloth insulation blankets or frost cloths (available at nurseries and home improvement stores) to throw over sensitive plants. Old sheets work, too. Use cloth; plastic lets in the cold. When tenting, allow some room for air circulation; that helps retain heat.
* If frost is in the forecast, water frost-sensitive plants lightly in the afternoon if the soil is dry. Moist soil retains more heat. Well-hydrated plants are less likely to suffer frost burn.
* Don't water succulents before frost. Extra irrigation actually increases their frost risk. Instead, cover them with frost blankets.
* Pull mulch away from frost-sensitive plants; it retains cold as well as moisture.
* Know your garden's cold spots. Plants stay warmer on mounds or in raised beds; the lowest point in a garden is often the coldest. Houses radiate heat, making warm zones. Plan and plant accordingly.
* If temperatures are forecast below 30 degrees for more than 30 minutes, harvest ripe citrus to avoid damage. Lemons and limes are the most at risk.
* Lime trees are the most frost-sensitive citrus, suffering damage at 29 degrees. Other citrus withstand a few degrees colder, but not much. Protect citrus by irrigating before nightfall, sheltering with frost blankets before sunset and/or wrapping the trunk with insulation. Rags, blankets, sheeting or pipe insulation works.
* String old-fashioned Christmas lights around tree trunks of sensitive trees. LED lights won't work; they give off no heat.
* If plants still get burned, leave damaged foliage alone. Those brown leaves will help insulate the plants from further harm.


0 comments have been posted.

Newsletter Subscription

Sacramento Digs Gardening to your inbox.

Local News

Ad for California Local

Dig In: Garden Checklist

For week of March 19:

Spring will start a bit soggy, but there’s still plenty to do between showers:

* Fertilize roses, annual flowers and berries as spring growth begins to appear.

* Watch out for aphids. Wash off plants with strong blast from the hose.

* Pull weeds now! Don’t let them get started. Take a hoe and whack them as soon as they sprout.

* Prepare summer vegetable beds. Spade in compost and other amendments.

* Prune and fertilize spring-flowering shrubs after bloom.

* Feed camellias at the end of their bloom cycle. Pick up browned and fallen flowers to fight blossom blight.

* Feed citrus trees as they start to blossom.

* Cut back and fertilize perennial herbs to encourage new growth.

* Seed and renovate the lawn (if you still have one). Feed cool-season grasses such as bent, blue, rye and fescue with a slow-release fertilizer. Check the irrigation system and perform maintenance. Make sure sprinkler heads are turned toward the lawn, not the sidewalk.

* In the vegetable garden, transplant lettuce and kale.

* Seed chard and beets directly into the ground.

* Plant summer bulbs, including gladiolus, tuberous begonias and callas. Also plant dahlia tubers.

* Shop for perennials. Many varieties are available in local nurseries and at plant events. They can be transplanted now while the weather remains relatively cool.

Contact Us

Send us a gardening question, a post suggestion or information about an upcoming event.