Everywhere we look, ornamental trees are under attack here in southern Louisiana. It’s quite concerning to say the least.
Over the last five years, we have witnessed the large majority of our prized Canary palms dying in the New Orleans Mid-City area from Texas Palm Decline.
Then this summer, we noticed that Crepe myrtles are suffering badly with a particularly nasty case of a disease called Cercospora. Crepe myrtles get a mild case of it every year, but this year it’s easily the worst we’ve ever seen. Also, the destructive crepe myrtle scale appeared on various varieties of Crepes throughout the City.
And most recently, we’ve observed a dangerous threat to our local Ginkgo Biloba trees.
Warning Signs of Ginkgo Tree Disease
Normally this time of the year Ginkgo trees foliage is a relatively pure green color in appearance. But this year, the trees look peculiar.
The lack of foliage on them jumps out – almost like a skeleton tree where you can see all of the branches and twigs, almost a winter version in appearance.
This is definitely atypical for this time of year.
Upon closer inspection, we noticed leaves cupping and some burn on the foliage. This is definitely not normal.
And the more we looked around, we started noticing this disease on every Ginkgo in the city!
You read that right… EVERY Ginkgo we saw in metro New Orleans seemed to have it. Except 1.
We found 1 healthy tree which just happened to be planted in a large pot, so it hadn’t been planted in the ground and exposed to local soil conditions. Is this a clue?
Theories on Rampant Local Tree Disease
In 40 years of serving local Louisiana trees, you learn a few things. And the number of species we see under attack by disease this year is not an accident.
Ornamental trees like palms, crepe myrtles and Ginkgo are not native to our area. They’re imported. Transplanted. So they don’t occur here naturally.
Also, we’ve seen tangible changes in our local conditions due to heavy rainfall and erratic, atypical temperatures throughout the year.
We’re even seeing an all-out attack on lawns everywhere in the form of brown patch and webworm.
Suggestions for Saving Your Trees
However, if your trees are still healthy, there are a few steps you can take to help keep them healthy despite what’s going on around them:
- Avoid mass planting (5 or more) Ginkgo trees for the immediate future
- Make sure they’re planted in a well-drained site with sandy soil or on a hill (hills as defined by southern Louisiana standards)
- Turn off water if you’re irrigating
Don’t Wait Too Long Before Taking Action
We certainly don’t want to sound alarmist by sharing news like this with other professionals in the Green Industry. However, our job as professional arborists is to protect and preserve our local tree population. Also, we want you to be able to responsibly inform your customers to avoid investing in trees which may not live.
If you’ve noticed active disease on your trees, it’s time to evaluate your treatment options as soon as possible. We are currently experimenting with fungicides on the Ginkgo Trees to see if we can save them. We’re not sure if this will work yet as we’re still in the testing phases.
Contact us to request a consultation if you’re not sure whether your trees are affected yet.
At Bayou Tree Service, we are often contacted by concerned tree owners when they notice something different or “off” about their trees. That’s where regular tree maintenance comes in!
One of the most common trees that we get questions about this time of year are actually Crepe Myrtles!
Crepe Myrtles are among the most popular trees decorating homes, commercial, municipal and educational landscapes in New Orleans, Baton Rouge and throughout the southeastern United States. With their signature flowers that bloom in whites, pinks and reds, they are a beautiful sight to behold in southern Louisiana’s hot summer months.
But, have you ever noticed that your Crepe Myrtles’ leaves have black spots, or are changing colors or shedding before the autumn hits?
If this is happening to your crepe myrtle trees, are they still healthy?
What Are Those Black Spots?
If you’re noticing black spots on the leaves of your Crepe Myrtles, your trees are experiencing a disease called Cercospora.
Initially displaying dark spots, these leaves eventually turn yellow, orange or red and fall off your trees, well before the hot Louisiana temperatures have dropped and fall has begun. While Cercospora is a known disease of Crepe Myrtle trees, you need not worry.
What Can You Do?
First, if you’ve noticed these telltale signs of Cercospora, the disease has already taken ahold of your tree. There is no reversing it, not even by spraying your trees.
In fact, if a Crepe Myrtle tree owner truly wanted to control Cercospora, he or she would need to spray the tree every 7 to 10 days with a fungicide, from early summer into the fall. That’s simply too much tree maintenance for most Crepe Myrtle owners, especially considering how many of these beauties can be found across our local landscape.
Second, even though Cercospora may cause some unsightly discoloration of your Crepe Myrtle tree leaves, it is not a life-threatening disease.
Trees that are affected with Cercospora can be expected to reach their normal lifespan of more than 50 years!
Third, heavy summer rain showers are known to cause more and more cases of Cercospora in Crepe Myrtle trees. And we all know just how much rain we get in the summer in Louisiana!
You Can Relax 😊
The simple fact is, there’s really nothing feasible or worthwhile that you can do to prevent Cercospora from infecting your tree, but since it isn’t life threatening, it truly isn’t something to worry about.
And think about it. With so many Crepe Myrtles planted across the southeastern United States, they are a reliable, long-living tree, despite their tendency to become infected with Cercospora.
If you have a Crepe Myrtle that is displaying another issue, or other types of trees that you think may be diseased, we are happy to inspect them. Call Bayou Tree Service today at (504) 608-0712 in New Orleans, or in Baton Rouge (225) 414-4076.