Can those frozen plants be saved?


Succulents appeared to be particularly vulnerable to the below-freezing weather last month. These pictures show jade plants from Donna Kupke's yard. The one on the left was fairly protected against the house, while the one on the right was more exposed to the elements.

Credit: Donna Kupke

Robellini palms throughout the community displayed brown fronds after the January freeze.

Credit: Donna Kupke

The ficus at left survived the freeze by being in this location next to the house. The ficus at right originally was about 12 feet away from the house and completely exposed to the elements, showing what difference placement of potted plants makes toward protecting them from freezing temperatures.

Credit: Donna Kupke

These potted hibiscus plants appear to be a complete loss; however, a hibiscus in the ground (not pictured) shows signs of having survived the freeze.

Though damaged, this asparagus fern still has green fronds, indicating it survived the freeze.

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They are everywhere Canyon Lakers look. The plants that were so lush and lovely only a couple of weeks ago and now are brown and shriveled due to the recent cold snap. But what is the best advice for them now? Should homeowners cut off the dead parts? Water them more? Rip them out and start over? Or should they just leave them alone? And, more importantly, what should be done to protect plants from future frost or freezing conditions? Everyone seems to have a different opinion.

Before homeowners make any decision, they should understand just what happened. So, here’s the science of it, according to “Gardening Know How:” Frost freezes water in the plant cells, causing dehydration and damage to cell walls. Although the freeze damage to plant tissue can be detrimental, it’s actually the defrosting process that causes the most damage.

As a result of the cell walls that were damaged by the cold, the plant defrosts too quickly, killing leaves and stems. Think of putting grapes in a freezer. Once frozen, they can be taken out and eaten immediately; they look lovely and are quite delicious. However, within just a few minutes after removing them from the freezer, they become brown and shriveled and rotten-looking.

Experts say most plant tissue freezes at 28 degrees, but some plants are less cold hardy. The tropical and semi-tropical plants that are so abundant around Canyon Lake are at the greatest risk, as are new plants that aren’t established in the landscape. Also extremely vulnerable are potted plants and any tender new green growth on a plant.

Some of the more common tropicals seen in the community include hibiscus, dwarf schefflera, philodendron and bougainvillea. Banana palm trees and robellini palms are especially prevalant.

But what everyone really wants to know is whether their plants are forever ruined or if they can be saved. Actually, according to numerous gardening websites including “Ask,” “Gardening Know How,” “eHow” and “GardenGuides.com;” there are steps that can be taken to save most of the plants. Don’t be fooled by the brown leaves and limp branches. With prompt care, most of these frost-damaged plants can be rescued.

The banana tree is a favorite in Canyon Lake. Its large, beautiful palms make a lovely statement in tropical landscapes. It prefers warm weather, but can survive freezing temperatures for short periods. In most cases, the tree will survive because the root systems are protected as long as temperatures stay above 22 degrees Fahrenheit. Well-established trees will survive light freezes with minimal damage. The frozen flower stalks and leaf portions only of the banana tree can be removed immediately after a freeze, but the best course is to wait until spring to assess the true damage, according to “eHow Home.” Once the weather has warmed, trim away banana leaves that are broken, but leave the outer layers to insulate the live trunk.

An application of fertilizer will help with regrowth. Banana trees that have actually been killed will be mushy and unable to stand upright when given a moderate push. Trees that resist being pushed over are alive in the center. New growth will appear in the spring.

Robellini palms are one of the most popular landscaping plants within the community and most have suffered minimal to severe frost damage. According to “eHow Home” and “GardenGuides.com,” the best course of action for these elegant plants is patience. One can trim away only fronds that are completely brown with no green remaining. Leave any green fronds (even if they are only slightly green) on the tree for photosyntheses purposes as it will help the robellini recover.

Watch for new growth from the crown in the spring. Palms that were severely damaged should be watched carefully during the subsequent spring. Damage to very young and embryonic leaves within the bud may not show up for as long as six months after the freeze. If the new growth appears abnormal, it may be indicative of minor freeze damage and, in most cases, will grow out of this later in the season. If the new fronds suddenly collapse, the palm trunk most likely is unable to supply water to the fronds, which is a lethal result of freeze damage. Loss of the palm is inevitable.

With regard to all plants that have sustained frost or freeze damage, unless they can be moved indoors or to some sort of sheltered area, do not attempt to cut back the damaged leaves or stems. Experts caution against severely pruning freeze-damaged plants for at least several weeks. Give them some time to “bounce back” a little.

Plant owners can remove just the dead leaves without any stems if they are too unsightly, but if they can be tolerated for a little while, until any danger of freezing weather has passed, those dead leaves will actually offer an additional layer of protection should another cold spell occur. Instead, wait until spring to cut away the damaged areas. At that time, prune dead stems all the way back. Only the damaged portions of the live stems need to be trimmed as these will eventually regrow once warm temperatures return.

According to “GardenGuides.com,” since damaged plants have been weakened, they can be susceptible to attack by pests and disease (think of it as having been sick and having a weakened immune system). It is recommended they be sprayed with a copper fungicide (repeat after approximately two weeks), followed by a liquid nutrient and later a fertilizer (which should be repeated every three months).

If a gardener is responsible for the care of the yard, it is important that he be informed to wait several weeks before attempting to prune any dead foliage.

Planning ahead

While it is possible to save most frozen plants, it is best to prevent any damage in the first place. When frost or freezing conditions are expected, plan in advance. Weather.com usually provides a frost warning.

Experts recommend potted plants be moved to a sheltered location, preferably indoors or in a garage. According to “WikiHow,” if potted plants cannot be brought inside, they should be clustered together and the base of the grouped containers wrapped in blankets.

Protect vulnerable in-ground plants by covering them with light blankets, sheets or burlap sacks. Make sure the coverings touch the ground in order to trap the heat inside. These should be removed once the sun returns the following morning. If choosing to use any sort of plastic, don’t let it touch the plant because plastic is a cold conductor and could actually cause even more damage.

In addition to wrapping them, mounding soil or mulch around the base of in-ground plants will help to keep the root system protected. If plants become covered with frost, gently water them to melt the frost before the sun scorches the tender foliage. Water all plants 24 to 48 hours prior to the freeze so the dryness of soil and wind do not aggravate the damage further. Moist soil will absorb daytime heat and help maintain ground temperature.

The soil should be kept moist, but not soggy around the plants. Add water to thaw if the soil in potted plants becomes frozen. Turn off any automatic watering system so plants are not watered during the freezing nights. Sprinklers can be turned back on when the weather warms up a bit.

Most Canyon Lakers work hard to maintain their properties. A lot of time, money and effort is spent in the care of the thousands of beautifully landscaped yards in the community. Seeing so many of the plants that have suffered during the recent freezing weather can be depressing. But the good news is that most will be back to normal within a few short months.

By summertime, the freeze of 2013 will be history and the community's landscape will be back to normal. Canyon Lake residents are fortunate to enjoy Southern California’s beautiful and generally mild weather. It is often forgotten that it can actually get pretty cold – even if only once in a while.