With the freezing temperatures this week, there’s a strong likelihood that some of our plants might have been damaged. A few weeks ago we wrote about most of Tulsa County now being in USDA Growing Zone 7b. In growing zone 7b we should expect an average winter extreme low temperature of somewhere between 5 and 10 degrees. But just this week we found ourselves with temperatures down around 0 degrees. This is the type of winter extreme we would expect more or zone 7a to 6b. Because of this, some of our marginal plants might have been adversely affected.

By marginal plants I mean those plants whose upper limit of where they can be considered perennial would be in zone 7. Plants usually come with a reference on the tag showing which zones they do well in. For example, crapemyrtles typically say they will do well in zone 7-10 so we might get some damage on our crapemyrtles. Now this shouldn’t be like the damage we experienced a few years ago, but you still might have some branches damaged.

One of the challenges with freeze damage to plants is that you won’t know it until it starts to green up in the spring. Then you might notice some branches or areas of a plant that remain brown. The first thing to do is don’t rush to judgement. They may be damaged but still might recover, so give them a little time. But, if we get to May or June and you still don’t see any green, it’s probably time to prune out those dead branches.

Your plants will be at more risk if you didn’t put down any mulch last year. Mulch is a great insulator and helps protect the roots of the plant from these extreme weather events. If you didn’t put down any mulch, this year would be a good time to add a layer of mulch to your garden. A good source of mulch is the City of Tulsa Green Waste Site. This site is located at 2100 N. 145th E. Ave. And is open each day from 7:30 until 4:30 excluding Wednesdays. To drop off wood waste you will need an id showing you live in Tulsa County, but anyone can pick up mulch.

If you suspect freeze damage on your plants, be sure you keep your plants hydrated. This would be especially true if there are newly planted shrubs or trees you are concerned about. Established trees or shrubs only need a good watering once a month but newly planted shrubs should be watered more often. Mother Nature usually takes care of this, but if we go through a dry month, you ought to give them a good drink. Other than that, we just wait and see. Good luck!

You can get answers to all your gardening questions by calling the Tulsa Master Gardeners Help Line at 918-746-3701, dropping by our Diagnostic Center at 4116 E. 15th Street, or by emailing us at mg@tulsamastergardeners.org. Photo: Tom Ingram