Keep those greens warm

Steve Kawaratani

“Don’t knock the weather; nine-tenths of the people couldn’t start a

conversation if it didn’t change once in a while.”

-- KIN HUBBARD

“Moisture slips from leaf tips to the verdant ground below.”

-- CATHARINE COOPER

We face myriad garden challenges, as rain and cold appear to have

arrived again. Good judgment on tree selection and pruning really

shows up during and after major winter storms. In certain Laguna

climes, particularly along the Canyon Road, there is the possibility

of frost damage to ornamentals and fruit trees. Unanticipated wet and

cold weather conditions may damage our strawberries, early tomatoes

and basil.

Cold temperatures may injure or destroy certain plant tissues by

causing the water inside the plant to crystallize and rupture cell

walls. Many of our tropical and subtropical plants can suffer cold

damage once temperatures drop below 40 degrees. Maceration of the

plant tissue causes the protoplasm inside the cells to burst out,

causing the mushy look of soft tissue plants and the burnt, limp feel

of leaves.

Many gardeners believe that they can keep plants warm by wrapping

them up, just as we wear heavier clothing during cold weather. This,

however, does not hold true -- plants have no body warmth. Within a

few hours, they will be just as cold as if they had no protection.

You should know what temperature your plants are hardy to, in

other words, what is the lowest temperature they can tolerate. 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 your nonhardy plants are too large to move into

the garage? If the plants are moveable, try temporarily relocating

them under the eaves of your house. This location is warmer and less

exposed to the elements.

You may reduce the loss of heat by completely covering plants with

cloth tarps or burlaps. The corners are then pegged 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 and 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 together.

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 Plant Man’s advice, you won’t rush

the planting of cold sensitive flowers and vegetables until the end

of winter.

I happened to glance at the recently planted basil on our deck

today. It was clearly unhappy with the cold temperature. A fleeting

notion crossed my mind, that I should cover it with my pile jacket.

The thought quickly turned to laughter -- the jacket was the wrong

color for our house! See you next time.

* STEVE KAWARATANI is the owner of Landscapes by Laguna Nursery,

1278 Glenneyre St. in Laguna Beach. He is married to local artist,

Catharine Cooper, and has three cats. He can be reached at (949)

497-2438, or e-mail to [email protected].