GARDENER'S MAILBAG: Is it time to replace my lantanas?

By Neil Sperry
Special to the Herald Democrat

Dear Neil: My lantanas are 18 years old and have ceased blooming. Fertilizers have not helped. Is it time to replace them? 

If they did not bloom at all this past growing season, perhaps trees nearby have grown large enough to shade them excessively. Lantanas bloom on new growth. If they did not grow well, be sure that the fertilizer you use contains a high level of nitrogen. If they were very successful for many years, there is no reason that they would wear out. Last February’s cold could have weakened them enough to have set them back this year.

Dear Neil: We had a Chinese pistachio tree planted in January 2021. Over the summer its leaves begin to shrivel. In August we asked our full-service lawn care company what we should do, and they said that we needed to water it a great deal more. We did that, but the problem got worse. Then they sent out a tree expert and his recommendation was that we were watering it way too much. Meanwhile, the rest of the leaves shriveled, turned brown and blew off. What is the problem?

Chinese Pistachio Dying

It looks like the tree was planted very carefully. I see no evidence of sun scald to the trunk. Normally that doesn’t show up in the first year anyway. I can’t see any definitive cause in the photograph. The two guesses I would offer would be that the tree did get too dry one time during the summer. It isn’t difficult for that to happen because potting soil in containers is very porous and dries out more quickly than landscaping soil. It’s also possible that the February cold spell might have done damage to such a brand new tree, and that might not have manifested until the hot weather of summer. You’ll know the full extent of any damage once the tree tries to leaf out in the spring.

Dear Neil: What evergreen tree would you recommend between two 10-foot-tall tennis court fences?

That’s a wonderful question. I’d like to suggest something that would not require pruning since access would be difficult if branches filled up the space. But a tall tree won’t work, as the live oaks are proving. Please consider Oakland hollies from very large containers (since they don’t grow really rapidly). Space them 6-7 feet apart. They will eventually grow to be 10 to 12 feet tall and not quite that wide. If you want something more of a tree form, consider Little Gem southern magnolia. It’s much taller, but it would fit between the fences. It does drop leaves all through the season, so the litter might be an issue on the courts. Or you could use tree-form Nellie R. Stevens hollies. They’re stunning, but you’ll have to hunt for them. A good independent retail garden center will have them or can get them for you. Critical issue: whichever type that you choose, plan on watering your new trees deeply and regularly for their first several years. These types that I’ve mentioned need to be kept moist at all times and they don’t really give you very good hints when they’re dry. You’ll want to soak them every 2-3 days during the growing season.

Dear Neil: When should “pups” be transplanted away from a mature sago palm?

Early spring, just as the weather is warming and plants are starting to grow actively.

Dear Neil: I had a beautiful golden rain tree that was damaged by the February cold. This spring it lost big chunks of bark and I thought I had lost it. Now it is trying to send out sprouts from its base. I was planning to leave the original trunk and maybe tie up the new growth to it to help it regrow into a nice tree. Do you have any suggestions?

Golden Rain Tree

You actually have a Chinese flame tree (Koelreuteria bipinnata), sometimes called “southern golden raintree. It is decidedly less cold-hardy than the northern golden rain tree, and this year’s winter killed thousands of them back in the southern half of the state. If I had your tree, I would remove the old trunk immediately and retrain the strongest new shoot as it develops next spring. The root system was not damaged by the cold, so the new growth should come out vigorously. If you were to leave the old trunk in place it would be almost impossible to extricate it later.

Need Narrow Evergreen Trees

Dear Neil: I lost one Texas mountain laurel in the past 30 days and it looks like two more are on their way. They survived the big freeze, but now they look like this. What could be causing this?

Dead Texas Mountain Laurel
Dying Texas Mountain Laurel

The first thing I notice in your photographs is that the plants are both growing in very shaded locations. Texas mountain laurel is native to hot, sunny hillsides in arid parts of the state. However, excessive shade would not kill plants suddenly like this. I really do think this is latent freeze damage. We are seeing many plants that have cratered in late summer and fall from the results of damage from February’s cold.

Have a question you’d like Neil to consider? Mail it to him in care of this newspaper or e-mail him at Neil regrets that he cannot reply to questions individually.