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Dallas Morning News - November 21, 2019

Freeze Damaged Plants


It's happened again. The temperature dropped last week by 50 degrees in just over 24 hours. Low 20's is a hard and unusual freeze for November. It makes a mess but the main damage for the well-adapted or native plants is that the anticipated fall color has been hammered and lost in a large percentage of trees and shrubs. Although it may not look like it, the woody plants will be fine and grow normally next spring. Worse thing for the Garrett garden is that that my big ginkgo has fried foliage and will have poor fall color for the second year. Same thing for the little ones in pots. Bummer!


Howard's ginkgo tree leaves took a freeze hit, affecting this fall's color


Most of the plant damage is cosmetic but I have few suggestions that might help the gardeners out there. For now the severely burned annuals like periwinkles and pentas should be cut to the ground or pulled up and tossed into the compost pile. Perennials such as lantana and salvias should be cut back to the ground and mulched with shredded native tree trimmings.


The severely burned should be cut to the ground or pulled up and tossed into the compost pile

Stunned shrubs, trees & other woody plants need to be left until they start to grow in the spring


Stunned shrubs, trees and other woody plants need to be left alone for a while until they start to grow in the spring. Be patient. Wait until temperatures are warm in April and there is new growth. Once you see budding and leafing, you can identify dead limbs and cut them away back to the point of healthy growth. Clean your pruners between cuts - we don't want to spread disease that might be present on the stressed plants. Bleach is often recommended but that is a bad idea. Hydrogen peroxide works better and is non-toxic.


Plants usually don't need a lot of irrigation in the cool and cold months but don't let the soil completely dry out during windy, dry periods either. Don't fertilize . . . yet: We'll do the first major organic fertilization of all plantings, even the damaged ones, in late January or February.


Protecting tender plants with covers or floating row cover can offer several degrees warmth to prevent freezing


Yes, we will have more cold weather - so get the floating row cover ready – especially for any newly plant cool season plants like pansies and dianthus. Covering smaller plants, especially potted plants, protects against severe cold. If you did it before the last weather event, you see how well it works. Floating row cover is the white, lightweight, synthetic fabric available in nurseries under several brand names.


I've recently learned that some homeowner associations don't allow the thin white fabrics that work so well, but make gardeners use the heavier green products. Bad idea. Although protecting from cold and wind, the thin white fabrics let light and air through and can be left on the plants for weeks if necessary without damaging them. The opaque, heavy, green stuff blocks the light and air circulation and can severely damage plants.


Stay warm!




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