Red Rocket Crape Myrtle Leaves Turning Dark/Black

[Nicki]

Hi there! I'm hoping that some more experienced gardeners can offer some advice or solutions for my crape myrtle problem.

I purchase a small 7-gallon Red Rocket crape myrtle from a well-reviewed nursery where I live in Austin, TX and planted it about a month ago. When I got it, the leaves were all nice and green. However, in the past week, a good amount of leaves near the top of the tree have turned a dark black color. There's nothing on the leaves, like sooty mold. They're just turning black!

I flooded the tree when I first planted it and have been watering it about 3 times per week. I have clayey soil and live on a newly developed lot. When I planted, I added compost to the soil, as per nursery advice. However, it was pretty hard to mix the compost into the clay soil texture, so I probably wound up creating a bit of a layered effect of clay/compost. I also felt like there may be more bug bites on the leaves than I thought were present when I first bought the tree (if that means anything).

I am a totally clueless beginner when it comes to plant life. I've never kept any plant I owned alive for more than a month and am really worried that I've failed yet again. As an adult, I've always lived in apartments, but I recently purchased my first home. Now, I must keep a whole yard and lots of other plants alive, and I just don't know what the hell I'm doing.

 

[Chuck]

Hi there! I'm hoping that some more experienced gardeners can offer some advice or solutions for my crape myrtle problem.

I purchase a small 7-gallon Red Rocket crape myrtle from a well-reviewed nursery where I live in Austin, TX and planted it about a month ago. When I got it, the leaves were all nice and green. However, in the past week, a good amount of leaves near the top of the tree have turned a dark black color. There's nothing on the leaves, like sooty mold. They're just turning black!

I flooded the tree when I first planted it and have been watering it about 3 times per week. I have clayey soil and live on a newly developed lot. When I planted, I added compost to the soil, as per nursery advice. However, it was pretty hard to mix the compost into the clay soil texture, so I probably wound up creating a bit of a layered effect of clay/compost. I also felt like there may be more bug bites on the leaves than I thought were present when I first bought the tree (if that means anything).

I am a totally clueless beginner when it comes to plant life. I've never kept any plant I owned alive for more than a month and am really worried that I've failed yet again. As an adult, I've always lived in apartments, but I recently purchased my first home. Now, I must keep a whole yard and lots of other plants alive, and I just don't know what the hell I'm doing.View attachment 12649 View attachment 12650

I know you said it isn't sooty mold but that is exactly what it looks like. Are you sure there are not a bunch of aphids lurking on the back side of the leaves? Those purple leaves are what the leaves look like shortly before turning black

 

[Nicki]

I know you said it isn't sooty mold but that is exactly what it looks like. Are you sure there are not a bunch of aphids lurking on the back side of the leaves? Those purple leaves are what the leaves look like shortly before turning black

Thanks for your input! I checked the tree this morning and couldn't find any bugs on the top or bottoms of any of the leaves I checked. However, I did note that the undersides of the leaves still looked nice and green while the tops of the leaves were all dark/black. We got a bit of rain yesterday afternoon, though, so would any aphids that were there have buzzed off because of the weather? Regardless, I've never noticed any bugs on the tree before, and I've been checking on it quite frequently.

As of last night, when I checked the crape myrtle in the evening, about the top 20% of the tree's leaves were black. I went to bed and thought, "It's going to be okay. If all else fails, I'll hopefully just have to remove the top 20% of leaves and branches." But this morning, the ratio had flipped. Over a period of about 12 hours last night, the top 80% of the leaves have turned black with the bottom 20% remaining green. It's only about a 4-foot-tall tree, so I feel like it can't afford to lose much of itself.

I had gotten it from a nursery about a month ago and planted it in the middle of my front yard where it gets full sun and nearly no shade. I don't know how much sun it got at the nursery (they brought it to the counter for me), but could the issue be that it's suddenly getting much more sun than it had previously received at the nursery and the tops of its leaves (which obviously face the sun) are turning dark as a reaction? Plus, it's definitely starting to heat up where I live in Austin as well.

 

[Chuck]

Thanks for your input! I checked the tree this morning and couldn't find any bugs on the top or bottoms of any of the leaves I checked. However, I did note that the undersides of the leaves still looked nice and green while the tops of the leaves were all dark/black. We got a bit of rain yesterday afternoon, though, so would any aphids that were there have buzzed off because of the weather? Regardless, I've never noticed any bugs on the tree before, and I've been checking on it quite frequently.

As of last night, when I checked the crape myrtle in the evening, about the top 20% of the tree's leaves were black. I went to bed and thought, "It's going to be okay. If all else fails, I'll hopefully just have to remove the top 20% of leaves and branches." But this morning, the ratio had flipped. Over a period of about 12 hours last night, the top 80% of the leaves have turned black with the bottom 20% remaining green. It's only about a 4-foot-tall tree, so I feel like it can't afford to lose much of itself.

I had gotten it from a nursery about a month ago and planted it in the middle of my front yard where it gets full sun and nearly no shade. I don't know how much sun it got at the nursery (they brought it to the counter for me), but could the issue be that it's suddenly getting much more sun than it had previously received at the nursery and the tops of its leaves (which obviously face the sun) are turning dark as a reaction? Plus, it's definitely starting to heat up where I live in Austin as well.

This is a mystery. I guess it could be sunscald although I have never seen a crepe myrtle have it and I have a few of them on my property. What do the leaves do when they turn black? Do they curl and fall off or do they hang onto the tree. Hopefully they fall off. If they don't it might be a more serious problem involving the soil itself. You said it was on a newly developed lot and on that type of property they normally add fill dirt to level and grade for new construction. It could be possible that the soil is contaminated although I think it unlikely

 

[Nicki]

Well, they only started turning black about a week ago, but all the black leaves look perfectly fine and healthy as of today (except for being dark/black, of course). I haven't noticed any of them curling, wilting, drying up, or falling off. Before I purchased the house and moved in, landscapers planted Texas green sage, society garlic, and a couple fluffy ornamental grasses, and they're all doing fine and looking pretty. I also planted two pride of Barbados plants at the same time as the crape myrtle (about a month ago), and they look the same now as when they were planted.

I imagine that my neighbors likely have pretty similar soil, as we don't have very big lots, we live close to each other, and our houses were all built around the same time. I'd say my front yard and back yard combined is about 2,000 sqft, and it's the same for my neighbors. Their plants and trees are all looking nice and green.

About three weeks ago, I spread Scotts Southern Weed and Feed on my lawn and maybe got a bit of the product in my plant beds, though I tried to keep it away. Upon reading the back of the bag's fine print, I saw that it was not to be used on Bermuda grass and was for St. Augustine only. Well, Bermuda is exactly what I have! I had naively purchased and used the product thinking, "Well, it's called Southern Lawn Weed and Feed, and I have a Southern lawn, so I guess this makes sense." (Yes, I now realize that I should have read every letter of the fine print, and that was my first lesson learned as a clueless new home/lawn owner.) After realizing my mistake, I was worried that it would kill everything it had touched, but my Bermuda lawn seems no worse or different at all (I guess that's a testament that the product doesn't work to kill Bermuda and promote St. Augustine grass, like it claims). My other plants don't seem any different, either. So I'm not sure if the Southern Weed and Feed product may have impacted the crape myrtle at all since it didn't seem to affect anything else, but I suppose it's worth disclosing.

 

[Chuck]

IMO Scotts Weed and Feed should be banned. I can't begin to describe just how many plants have been damaged or killed by it. It leaches through the soil when it rains or is watered and stays in the soil for about 6 months before it finally goes away. Any plant downhill will in different ways be affected by it. I hope it isn't the case. But if it is it doesn't necessarily mean it will kill your tree. If the black leaves curl and stay on the tree I wouldn't count on it though. If they fall off they will more than likely regrow

 

[Nicki]

Well, my small front yard slopes upwards toward the house, and the tree is planted in the middle of the yard, so it is downhill from the house/higher area in that case. The other plants that are doing fine are close to the house and therefore at a higher elevation. I definitely learned my lesson about using Weed and Feed products and will never try that again. I thought that the product hadn't seemed to make any impact for better or worse, but maybe that's the culprit causing my crape myrtle leaves to darken.

I really hope the tree doesn't die! I'll feel awful if I spend all that money and time planting a nice, healthy tree just to immediately kill it with Weed and Feed. I wish there was something I could do to fix it.

 

[Chuck]

Well, my small front yard slopes upwards toward the house, and the tree is planted in the middle of the yard, so it is downhill from the house/higher area in that case. The other plants that are doing fine are close to the house and therefore at a higher elevation. I definitely learned my lesson about using Weed and Feed products and will never try that again. I thought that the product hadn't seemed to make any impact for better or worse, but maybe that's the culprit causing my crape myrtle leaves to darken.

I really hope the tree doesn't die! I'll feel awful if I spend all that money and time planting a nice, healthy tree just to immediately kill it with Weed and Feed. I wish there was something I could do to fix it.

There is. Get some molasses and mix 2 oz per gallon of water and drench the tree's soil. This will help bring more microbial life around the roots of your tree which will enrich the soil and at the same time helping rid you soil of any contaminates.

 

[Nicki]

Thanks! I have some blackstrap molasses in my pantry. I'll do that this evening to benefit the soil. I visited with the nursery where I bought the plant earlier today and was told that the leaves of the particular Red Rocket crape myrtle variety I have usually darken before the tree produces its dark red blooms each year. The nursery employee showed me some of the leaves on the Red Rockets they had for sale, and indeed they were pretty dark, thought not quite as black as mine and not so many leaves changing color. He agreed that the Weed and Feed may have stressed the plant out some, adding to the already dark color that the leaves apparently are supposed to develop.

I'll continue with the tree's regular watering and care and see what happens I guess. And I'll definitely be more mindful about what I apply to my lawn and plants rather than just doing whatever the Home Depot TV commercials tell me to do. And definitely no more Weed and Feed!

 

[CrapeMyrtleNOLA]

Did your crape myrtle survive? I have a new one that is doing the same thing. Leaves were green when I bought it. After less than 2 weeks, the leaves are turning dark maroon on the top surface of the leaf, while still green on the under belly of the leaf. I'm worried about it's health. Not sure what I'm doing wrong. I'm in New Orleans, where CMs usually thrive. Overwater? Underwater? I have no idea. Did yours survive?