GARDEN FANATIC:Caring for plants on cold winter nights

“The weather is like the government, always in the wrong.” -- Jerome K. Jerome

“The coldest winter I ever spent was a summer in San Francisco.” -- Mark Twain

Gardeners face a myriad of challenges as cold nights have arrived with consistency. In certain Laguna climes (like the canyon), there is the possibility of frost damage to ornamentals and fruit trees. Unanticipated wet and cold weather conditions may damage strawberries, early tomatoes and basil.

Many of our tropical and subtropical plants can suffer cold damage once temperatures drop below 40°F. Cold temperatures damage or destroy certain plant tissues and then the water inside the plant crystallizes. Destruction of the cell walls allows the stored water to burst out, creating the mushy look of soft-stemmed plants and the burnt, limp feel of leaves.

Many gardeners believe they can keep plants warm by wrapping them up, just as we wear heavier clothing during cold weather. This, however, does not hold true, as plants don’t possess body warmth. Within a few hours they will be just as cold as if they had no protection.

One should know what the lowest temperature is that plants can tolerate in order to survive. Plants that are cold sensitive cannot be expected to survive outdoors with any amount of covering during freezing conditions. Only artificial heat indoors will sustain them over the winter.

What can you do if it is not practical to move non-hardy plants into the house or garage? If the plants are movable, try temporarily relocating them under the eaves of your house. This location is warmer and less exposed to the elements.

One may reduce the loss of heat by completely covering plants with cloth tarps or burlaps, and staking the corners into the ground. If this is undertaken at sundown, the radiant heat of the soil will keep space around the plants warmer than the outside air temperature. Remember, it is almost useless to just drape plants with clothing, newspapers or tarps.

As last resorts, portable heaters and fans can keep temperatures from falling too low around sensitive plantings. This isn’t very practical when it is raining, because of the danger of water and electricity. During periods of clear, cold weather, sprinkling plants lightly with water will often save them. If the temperature is below freezing, however, sprinkling will do more harm than good.

Perhaps the best solution is to know what zone you live in (the Sunset Book is an excellent guide) and how low temperatures might drop.

Armed with this information, you can plant hardy perennials for your locale.

And if you follow the Catharine’s advice, you won’t rush the planting of cold sensitive flowers and vegetables until the end of winter. See you next time.