Get things back on track by deciding what to do with your lawn’s crape myrtles

It’s been almost three months since Winter 20-21 dealt one of the unkindest blows ever to our beloved crape myrtles, and it’s time that we made some decisions on how best to get things back on track.

I’ve spent hundreds of hours driving through neighborhoods, looking at living examples, examining photos via emails and Facebook posts and talking to arborists and nurserymen, and I’ve come to some conclusions I’m finally willing to share.

Before I get into all that, however, I’d like to point out that we’ve been through extreme cold before here in North Texas.

This one was vastly different.

It impacted plants differently, and it impacted different plants. Oaks are the best example. Experts shake their heads and simply say, “I’ve never seen anything like it.”

I can say the same thing about crape myrtles.

Varieties that historically have had issues with cold came through rather well. Other old stalwarts that have laughed at the winters of 83-84 and December 23, 1989, aren’t laughing now. So that part of the story remains to be written. But, without getting down to specifics about the various varieties, here’s what I can tell you about the crape myrtles I’m seeing.

Those that look normal

There is a large percentage of our crape myrtles that looks like nothing ever happened.

They leafed out pretty much on time, and their growth is dark green (or purplish-green), just as it should be.

For these plants the main care tip we give is to apply a high-nitrogen fertilizer similar to what you’d put on your turf around them and water them deeply. They will be fine.

Some are leafing out sparsely

These are actually the ones that are keeping us guessing.

Many have strong sprout growth coming up around their bases, and it’s our recommendation that those sprouts be left in place for several more weeks. It’s entirely possible that they may be needed as new trunks if the old top growth declines as it gets hot.

On the other hand, if you see your plant filling in with strong new growth as it warms up, and especially if it begins to join the ranks of the normal looking crape myrtles, then you can begin to remove the unneeded sprouts so that all the moisture and nutrients can be sent to the tops.

Some plants appear dead with no new growth

There is a small percentage of our crape myrtle population that has frozen back to the ground completely.

Almost all will come back from their roots with vigorous new sprouts, but the tops will need to be removed soon so those sprouts can develop straight and strong.

It becomes much more difficult as they grow taller. Cut the old trunks to within an inch or two of the ground and begin the job of retraining the plants. It’s not as bad as it might sound, as I’ll explain.

How to retrain a crape myrtle

Let’s assume you have a plant that has either frozen completely back to the ground or that is damaged enough that you’d prefer not to wait on it to fill itself in.

How can you retrain it using the strong shoots it will produce from its root system?

(Note: This is the same technique we recommend for a tree-form crape myrtle that has been topped, since that ruins the plant’s natural growth form. The only difference is that that pruning is normally done before the plant leafs out and begins growing in early spring. This pruning to correct winter damage needs to be done right away – in May.)

Cut the old trunks back as close to the ground as you can. Small stems can probably be cut with a thin pruning saw, but an old, thick trunk will probably require a chain saw.

As much as possible, leave any shoots that are already growing in place. However, if that’s just not possible, don’t fret. Plenty more will be produced. It’s not uncommon to have 20 or 30 new shoots spring up around the old stump.

When the shoots are 8 to 10 inches tall, thin their numbers to the best 10 or 12. You might want to put three stakes around the cluster to keep animals, garden hoses, mowers and other things from dragging across them and snapping them off. They are quite brittle at this point.

By fall these stems will be 18 to 24 inches tall. Reduce the number to seven and secure each one to a thin stake with plastic plant tie, again, just to keep them from being broken.

Next spring these shoots will grow very rapidly. Once they become somewhat woody next growing season, choose the three or five (stick with odd numbers for a more natural look) that are most vertical and remove all the rest. These will be the new trunks.

As the trunks grow, gradually remove the side branches to encourage the plant to grow tree-form. Never remove branches more than 4 to 5 feet up the trunk. Leave the trunks attached to the stakes until they’re strong enough to support themselves when blooming.

One additional care tip

If you have had an issue with crape myrtle aphids or bark scale and the subsequent black sooty mold that grows in the sticky “honeydew” residue these insects leave behind, apply Imidacloprid as a soil drench around the middle of May.

Mix it and pour it around the drip lines of your plants and it will get into the plants’ vascular systems, stopping the insects and stopping their activity. No insects: no sooty mold.

You can hear Neil Sperry on KLIF 570AM on Saturday afternoons 1-3 pm and on WBAP 820AM Sunday mornings 8-10 am. Join him at www.neilsperry.com and follow him on Facebook.

This story was originally published May 7, 2021 at 5:30 AM.