How to Kill Bark Scale on Crape Myrtles

July 17, 2016

We Texans sure do love our crape myrtles, unfortunately so does this fairly new pest to North Texas called bark scale. Do not fear though, as it’s easy to treat. Crape myrtles are a very hardy trees with lots of reserves, so it would take several seasons of bark scale for the tree to succumb to this pest. Bark scale originates from China and was brought to the U.S. in 2010. A&M has identified this pest as Eriococcus lagerstroemiae, and suspects that it was brought into the U.S. on a crape myrtle plant.

Bark scale on crape myrtle branch
Bark Scale along the branch of a Crape Myrtle

Many people who call us describe their trees as covered in white dots, or white cotton like bumps. They often think the white dots are a fungus, but it is in fact a bug. If you smash one when it’s alive it will actually ooze a reddish-pink liquid. You will oftentime see black sooty mold in addition to the white bark scale. Black sooty mold literally looks like black dust on your leaves and bark. The scale sucks the sap from your branches and tree trunks and then the sugars and yeast in the sap attracts the mold. They go hand in hand, but black sooty mold is really just a cosmetic issue. Treatment for the black sooty mold is not recommended and once the scale is terminated then the black sooty mold will disappear as well.

To kill the scale we recommend Bayer Advanced Tree and Shrub Protect and Feed Concentrate. It comes in granular and liquid form, and provides 12-month long-lasting systemic protection against the scale. The application rate depends on the tree trunk size, so you will just need to measure around the tree trunk and then pour the appropriate portion of granules or liquid around the base of the tree. Please read Bayer’s label for application rates needed for your tree, and for additional information. This product is readily available online and at most local home & garden stores such as Lowes and Home Depot.

Kill scale with Bayer Advanced Tree & Shrub Protect & Feed
Bayer Advanced Tree & Shrub Protect & Feed

I do want to mention that we are in no way paid or sponsored by Bayer. Over the years we have just found their products to be the perfect fit for our customers needs. Generic brands might be available, but just make sure they contain Merit. The best time of year to treat is between May-July when the scale are most active. After the scale has died you will just see a white shell as shown in the pictures above and you will not be able to see any pink coming from the scale once smashed. The white shells often take a while to fall off but you can gently brush them off to make the tree cosmetically more attractive.

Tuscarora Crape Myrtle Flower
Flower Cluster from a Tuscarora Crape Myrtle

Crape myrtles are still a tree that we highly recommend for North Texas as they are adaptable to a wide range of soil types, heat tolerant, and drought tolerant. Occasional pests here and there are going to happen to all trees as some point, but this is super easy to treat. Crape myrtles are also know for their resistance to powdery mildew, and can thrive in the sun and part shade.

I hope you have found this information helpful. I will be sharing more information and treatment plans for other common North Texas pests as they come about. The scale pictures were taken by my talented photog friend, Lauren.

-Denise



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58 thoughts on “How to Kill Bark Scale on Crape Myrtles”

  1. I’ve learned a lot via Google search regarding the Cotton White and black bark growth on my trees.

    First site I’ve come across that explains in layman terms on how to kill an save my trees.

  2. Another question then, we planted many photinia shrubs in our backyard, along our fence. We know that there’s a fungus or disease that is common to it, that can kill them. We lost about 5 shrubs to that illness, shortly after planting them. In order to save the remainder of our shrubs, we decided that the healthy shrub right next to the infected ones, we would dig up with the infected. We were able to save the rest of the shrubs by doing this. My question is, if this happens again, is there a preventative or can we treat them in an attempt to save them, or is it best to do what we did before? Of course I would prefer to save them if possible. I am what people would call a black thumb. My friends call me the plant serial killer. I don’t have a talent for these things. As a matter of fact, it’s quite the opposite, I seem to just kill any plant given to me; even following written instructions. I love plants. Having been raised in Germany where there is lots of vegetation.

    So glad & thankful to have found this article! It has great & simple info on how to identify and treat scales on our crepe myrtles. Not only was the information great; but, as others have stated, your instructions on how & when to treat, as well as describing the issue(s) in layman terms, made it easy for us non-horticulturalists / non-botanists /non-arborists to understand. I was glad to find out that we could save them!

    1. Hi Nicki, Thanks for your kind words about our blog. Yes with the Red Tip Photenias you likely have Entomosporium leaf spot. Their is no cure for this disease no matter what blogs you find on the internt. Howard Garrett probably has some oil treatment or something wild, but please don’t waste your money on such things. Thier is no cure and the infected plants must be destroyed and removed immeditely to hopefully stop the spread to others. Pickup all of the leafs on the ground as well and throw them away too. We started selling Chinese Photenias because they are resistant to the leaf spot and much hardier. The Chinese Photenia is actually a parent plant to the Red Tip Photenia. Hope this helps you and good luck!

    1. Hi Cindy, thanks for your comment. Yes, the black sooty mold will fade off the back over time. It is a slow process, but the bark will return to its original color down the road. Also be aware that the shell of the bark scale can remain on the bark for a extended amount of time as well. You can try taking a soft bristle brush with water to remove the bark scale and the sooty mold. Best of luck!

        1. Yes you can, and we recommend the Bayer product listed in the article. Really your only organic option is to smash each scale bug individually with some sort of utensil. Spraying the bark with water does not work. The oils do not work. We hate that the insecticides are the best method for this bug, but it’s the unfortunate case.

  3. Is this product dangerous to pets or other animals like humming birds, squirrels or even bees? Thanks!

    1. Hi Robin, thanks for your comment. I would definitely recommend that you contact Bayer with those questions. They will be able to advise you better than I. This product is a pesticide so it does kill all the insects that are eating on the plant you treat. You can always just throw on a pair of gloves and go to town smashing all of the individual scale bugs. I always use chemicals as a last resort.

  4. I would like to knew how using a systemic pesticide will affect all of the bees that nectar on the Crepe Myrtle flowers?

    1. Hi Meg, thanks for your comment. I have the same response for you as Robin. I would definitely recommend that you contact Bayer with those questions. They will be able to advise you better than I. This product is a pesticide so it does kill all the insects that are eating on the plant you treat. You can always just throw on a pair of gloves and go to town smashing all of the individual scale bugs. I always use chemicals as a last resort.

  5. Would this bark scale be the reason my myrtles didn’t bloom much this season? Do you recommend the Bayer spray over washing the bark with soap and water like some sites have recommended?

    1. Thanks for your comment. Several factors can cause Crape Myrtles to not bloom, or bloom far less than others around DFW. One cause is underwatering. Notice how beautiful the Crape Myrtles look around town after a nice rain passes through? Another cause is too much shade. As nearby shade trees grow and mature then the crape myrtles are left hidden underneath and struggle to get enough sunlight. Third cause could be tree stress and shock from pests. Scale and aphids are the biggest nuisances that I see on crape myrtles. As far as treatment goes, we do not feel that the oils, soaps, and washes from other sites work. We of course wish that more organic options really worked, but sadly they do not seem to be effective enough. I would say give them a try if you would like and then you can try the Bayer if all else fails. Bayer will have a 100% success rate on wiping out the scale. Good luck to you and we greatly appreciate you reading out blog. <3 - Denise

  6. Both you and the label says measure the trunk to see how much to use. For crepe myrtles, does this mean measure each trunk and add them together, or measure the overall circumference of the crepe at the base?

  7. I live in north Mississippi and purchased today the Bayer treatment. Is it too late to bother treating or should I leave the scales alone until spring? I realize it’s past optimal treatment time. Thank you.

    1. Hi Parke, thank you for your question. I would go ahead and apply it now. The bugs are still active right now. You can also treat again in the Spring as needed. Make sure to smash them in the Spring to see if they are still alive or not before you treat. Sometimes the shells take a while to fall off, but the bugs are dead. You will see a pinkish red ooze come out when smashed if still alive. Good luck!

  8. Hi All, I treated my crepe Myrtle with Bayer Advance in the beginning of May. For the first time after 10 years, the tree did Not blossom ( no indication of one single flower). Has someone experienced a similar situation? What happened? Will the tree blossom again?

    1. Hi Mary, I am so sorry that I missed this message last month. The crape myrtles here started blooming shortly after you posted this message. Have your crapes bloomed since? – Denise

  9. Hello. Thanks for your advice about white scale. One of my Crepe Myrtles (4′ high, raised from an Audubon sapling) had a heavy dose of white scale, accompanied by ants. I knocked off most of the scale with my hose sprayer, followed by spraying with a product called “Eight.” I then fertilized the plant with a granular product. Now that I’ve discovered your recommendations, how soon before I can apply the Bayer product, please?
    Thanks!

    1. Thanks for writing in Richard. I am not familiar with the product called “Eight” but the Bayer product I recommend can be applied at any time while the tree is not dormant so it’s actually absorbing the product. The ants will disappear later, don’t worry about them. They are just enjoying the sap that is already out on the bark and are not doing any additional damage to the tree. Really just cleaning up the wasted sap. Hope this helps. Reach out with any additional questions. -Denise

  10. Bark scale attacked both our beautiful Crepe Myrtles last year. The entire tree turned black and sappy. I went to several local garden centers, asked questions, showed pictures and nobody had a clue. My husband wanted to cut them down but I insisted we wait it out until the next growing season. I gave them a good pruning.

    Spring came and they still looked terrible. It was hard to watch all the other Myrtles in the neighborhood grow and bloom while ours just stood there all black and sad. It took a while but they did put out new growth. They even bloomed in late July and the Japanese Beatles had a celebration. I was so happy they were doing great.

    Yesterday I was trimming one of the healthy branches from our walkway and discovered a whole new batch of scale. Ugh! Im so disappointed. I know it is late in the season but I’m going to try the recommended product and cross my fingers. They are still in the active growing phase. Do you think one application will suffice? If not, when should I reapply? Will my Crepe Myrtles always have bark scale? Any additional knowledge is much appreciated! Thanks!

    1. I am so sorry to hear that you have such an ordeal with the scale. Scale is easy to treat now that you know what you have. I am actually working on an update to this blog with a more in depth treatment plan since some people see adult scale, while others might just see the larvae and crawlers. For crawlers and larvae, you will need a minimum of 3 applications in a 7-10 day rotation using the Bayer 3-in-1. For mature adults, please apply Bayer Advanced. Bayer Advanced lasts one year and it’s a good preventative. Honestly though, if you just see a few scale on that branch, then I would just smash those. Look in the crotches of the branches too, they love to hide in there.

      To give you tree a boost also apply Dynamite Fertilizer and Superthrive.
      Holler if you have any other questions. We are happy to help.
      -Denise

        1. Yes if the trees are not treated for 3+ years then it could hurt it enough to kill it in my opinion. I have not tested this as we are always constantly monitoring our trees. I just heard that number at an educational seminar. – Denise

  11. We just bought our house and they didn’t take care of the crepe myrtle. It has black bark all over the tree (looks like it’s been there for years), but it’ll still blooming in some parts. I want to save the tree since it still has some flowers. Should I peel off the black parts of the bark before I spray it? Or will that make the problems worst? It is really dry and crumbly when I touch it and it looks like it’s spreading to the healthy branches.

    1. Hi Abril, I am so sorry for the slow reply. April was so busy for us here at the farm. No peeling needed, just spray it as is. Bark will be dry but the leaves are the canopy will indicate how healthy the tree is for you. – Denise

  12. I was so happy to find this blog about my precious baby Crape Myrtle has this on it! Do we know if it’s something it could have picked up from the nursery it was purchased from? Or is it something it has accumulated since I planted it last summer. I actually thought it had died over the winter but was super surprised to see it start to sprout little leaves about a month ago! Then about a week ago these little white things started on the branches and have been frantically trying to find a remedy since I discovered it! Thank for explaining things in such a way that is so easy to understand!

    1. Stephanie, my apologies for my slow reply. April is just a crazy busy month for us. So glad you found this blog so helpful. Scale is all over Texas now and even if it didn’t come from a nursery its a matter of time before yours got it. Scale is just a part of life for crape owners now. Just treat and monitor. It’s easy to catch and crapes bounce right back. We do have to spray a few times for it at our farm. -Denise

  13. I’ve got about 30 CMs and almost all of them had the Bark Scale last year. Will it come back and will it kill my trees?

    You also said I can spray the Bayer any time the plant is NOT dormant? We’re here in N. E, Texas with high humidity and starting now warm to hot temps.

    Thanks for the info!!

    1. Hi Ed, so sorry for the slow reply. This is my first day to finally get a minute to catch up on messages since we get so busy in the Spring. For scale to kill a crape it would take several years of neglect. Most everyone can save their trees if caught early on. Crape myrtles are so hardy. Humid or not, you can treat as long as its during the Spring, Summer and Fall. – Denise

  14. Is the black soot and white scale harmful to pets and humans. Should I use a mask when cleaning the scale off?

  15. I was just about to remodel my front flower bed when I discovered the white bark disease bugs on my crepe myrtle tree. The tree sits at the end of my 20 foot long flower bed. I have already removed the old mulch and liner from the bed, I also cut down some old bushes. I was going to plant some new boxwoods and perennials in the bed, and put down new mulch & decorative rock. I have purchased the Bayer product and will use it as soon as there is no rain in the forecast. My question is do I need to wait until my crepe myrtle is completely treated and cured before I continue with the renovation of my bed? It is my understanding that these white bugs are exclusive to the crype myrtle, but I wasn’t sure if the Bayer product would affect the roots of any nearby plants in the same bed.

  16. I live in Northern Virginia and just noticed (June) little white dots all over my beautiful 20 year old 18 foot Crepe Myrtle. This evening I tried to spray them off w/the water hose and noticed they were moving…what a weird bug. I frantically googled them and saw your blog! Thank you so much! I’m going to run to Lowe’s or Home Depot first thing in the morning.

        1. Hi Pamela, thanks for your question. This time of year the chemicals are more easily absorbed up the tree since this is the growing season. I believe it’s estimated that the chemicals travel about 1′ per day, so depending on the size of your trees it could take 1-2 weeks. Also just know even if the scale die they do not fall off. Sometimes the shell stays on for a while even though they are dead. You can always check them by smashing them. If you notice any pink oozing out then they are still alive. -Denise

  17. Just ordered crepe myrtles to plant in my sunny yard where I need a little shade. So glad I found this post! I will get the Bayer to treat from beginning and prevent the scale. Thank you!!

    1. Hi Kathy, so glad you found my blog. I do not recommend treating just in case right now because all of the pollinators are out. I recommend waiting until you notice any scale to treat them. Plants also become resistant to chemicals just like humans with antibiotics, so overuse is not recommended. Hope this helps you but I do think its good to have Bayer on hand for once you notice any scale. -Denise

  18. Hello well just found out I also have these white fluffy critters on two small trees here in South Mississippi. One thing I was wondering that I didn’t see asked is about replacing.

    Both my trees are only 3 feet high. I’m thinking about just carefully taking them out in a trash bag as well as all the mulch. Only one has them but I’d replace both to match. If I do this and get new crepes when can I, or can I, plant them in the same spot in yard? Do I need to wait a season before planting or treat the ground with anything so the new trees don’t potentially get these critters?
    Thx for all the advice here and your time

    1. Hi Mike, Honestly I would try to save them if you can. You will be throwing away a lot of crape myrtles if you toss them out every time due to bark scale since it’s so prevalent now. Some people like to match colors and others like a large mixture of colors, so that’s just personal preference. I would not wait and I would go ahead and plant them. Critters will always be out and about but only treat when you actually see something and try not to treat while they are blooming. Our pollinators are in severe decline. Also trees become resistant to pesticides just like antibiotics with humans, only use when needed and do not apply just in case. – Denise

      1. Denis, thank you for your reply and taking the time to help Really appreciate it and reading over all the other comments.

  19. Thanks for all the info. I do have a question about pruning. I like mine smaller like a large bush. How and when do I prune them to keep them smaller. The other question. Is just the opposite. I would like to have larger crape Myrtles in the back , tree height. How do I get them to look like a tree. When I prune the ones I have.i just get more lower growth. I have seen some picture of crape myrtles that have pretty good size branches/ trunks. How do I get that look.

    1. Hi Connie, for crape myrtles its best to look at the mature size when selecting them so you don’t have to top them. Sounds like you need to swap your crape myrtle spots. I would look at some of the dwarf varieties for the front. For the back some of the large crape myrtles are the Natchez, Muskogee and Tuscarora. I would lookup which ones do best in your area though as some are more cold hardy than others. Here in our personal gardens we prune our crapes up about twice a year to keep the trunks cleaned up. As they mature they will get fewer shoots off the trunks but the sprouts will still come up. – Denise

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