1 week Ago By NEIL SPERRY
Dear Neil: What is wrong with my live oak? I hope it’s not a disease, since I have five others in my yard, and I don’t want it to spread. What should I do? A: You need to have an International Society of Arboriculture certified arborist or other veteran tree expert, forester or plant pathologist, hopefully from the Texas AgriLife Extension examine the tree and probably take samples for culturing in the Texas A&M Plant Disease Clinic. There is definitely something wrong with this tree, almost assuredly within the wood of the tree.
The bark is splitting and appears about to separate from the rest of the trunk. It looks like there may be some type of mushroom growth forming beneath the bark on the right side where you can see a bulge. If you can see any mushrooms on the trunk or coming out of the soil, that would further confirm it.
I can’t tell much just from this one photo other than to know that something is amiss. At this point it perhaps has not spread, but the professional will be the one to judge that. Dear Neil: We have recently noticed spots on the stems of our holly plants.
What is causing this, and what can we do? A: I’ve spent 45 minutes looking at your photos and online working through major university websites where hollies are huge commercial crops. At best, I have only a guess. First, the plants look hungry.
They need nitrogen. It’s quite late in the season, but I’d still be tempted to water them once with a liquid nitrogen food. That’s not the source of the spots, but the plants need some vigor to get them growing again.
I also see dead leaves beneath the plants. That makes me wonder if they might have gotten too dry late in the growing season. Again, it’s not the cause of the spots, but it didn’t help the plants.
As to the spots, I can’t tell if they’re due to disease or insect damage or something else. It’s funny that they’re only on the main trunks and not on the twigs or leaves. That makes me wonder if it could have been some type of beetle rasping on the bark, or perhaps even hail damage.
If hail, it would be on one side of the trunk. Beetles and diseases would have been universal. Start with the fertilizer and repeat it come spring.
If you feel a disease might be involved, if you can collect a specimen that wouldn’t mean sacrificing the entire plant, send it along with photos to the Texas A&M Plant Disease Clinic in College Station. Fees and mailing instructions are on their website. I’m sorry my answer was still vague.
I hope I sufficiently explained why. Dear Neil: I need hints to help my mom keep her jade trees alive. She has killed several in the past.
They have received filtered sunlight on the patio all through the growing season, but now it’s time to bring them into the greenhouse during freezing weather. Please advise. A: Jade plants are fairly forgiving as long as they’re given very bright light, perhaps even full sunlight, in the winter and temperatures of 60 degrees or warmer.
We know we have them too dark if their leaves shrivel and drop off in large numbers. Do not put them right against the heat source and be sure that gas heaters are vented to prevent toxic fumes from accumulating. Mealybugs love jade plants and other members of their plant family.
If any should show up, use cotton swabs dipped in rubbing alcohol to rub them off gently. Do not spray with Malathion. Jade plants and other succulents are very sensitive to it.
Dear Neil: I’m attaching two photos. One is to show you our venerable old live oak and its importance to our house and our landscape. The other shows some white patches of bark.
They’re easy to spot alongside the more normal darker bark. Our certified arborist is scheduled for his regular visit later this month. I wondered if you had any insights before he comes.
A: Great observation and wonderful tree. I’m going to go out on a limb (old horticultural term.) I see rows of woodpecker holes on these limbs, but I see none in the gray bark.
I wonder if there might have been repeated woodpecker “attacks” to the limbs where the bark is now the lighter color. It looks like newer bark that might have formed in the past year or so as the tree tried to produce new bark over the woodpecker “damage.” The tree looks so healthy I don’t think there’s any reason to ask for an earlier appointment.
I would just ask your arborist for his or her opinion. I’ll bet there is nothing bad going on. Dear Neil: I have a 3-year-old hibiscus plant that is growing, but it’s looking sparse in the middle.
It seems to bloom year ‘round. When do I need to prune it, and by how much? A: There are many types of hibiscus plants. I wish I had a photo.
I’m going to assume, since it’s flowering year ‘round, and since it’s survived several winters, that it must be a tropical hibiscus that you’re growing indoors in the winter in a very bright setting (hardy perennial hibiscus die back each fall, even when temperatures are warm). So, with that assumption, you may need to trim it back beyond the bare area. Hibiscus plants flower on their new growth, and the only way to get new growth down low on the plant will be to do a major trim, perhaps repot it into fresh potting soil, apply a high-nitrogen, water-soluble plant food, and get it back into bright light and warm temperatures.
I’d suggest you take a photo of the plant to a local independent retail garden center and get a second opinion on my reply..
