Hydrangeas not blooming? You’re not alone
Q: I’ve had beautiful hydrangeas (see photo from 2014) for 16 years, but the past two years, no blooms. I haven’t changed how I care for them. What might be wrong? They are in filtered sun.
A: There are other variables that could be involved. I’ll list things that cross my mind.
The shade might have become heavier as trees grew larger or denser. Perhaps you changed the time of year that you prune them. (They should not be pruned in fall or winter.)
The first killing freeze last year was unusually early, and that damaged a lot of primordial flower buds on many types of plants that flower in late winter and early spring. That might have damaged your hydrangeas.
Try to remember if others’ hydrangeas bloomed this past spring. Many gardeners in big parts of Texas have reported this exact situation to me, and I saw very few hydrangeas blooming where I live.
Q: I read your recent answer about live oaks losing leaves. The leaves on my tree do not show disease, wilt, galls or anything else that I can recognize. Some of them do appear to have been torn loose along with their twigs. Any ideas what might be causing this? Should I be concerned?
A: This is almost always the result of damage by squirrels or birds. I see it all the time. There isn’t anything you can do about
it, and it certainly doesn’t present any risk to the tree. I see no call to action.
Q: I want to plant ryegrass seed in my yard, but about a month ago I spread a leftover combination of weedkiller and fertilizer over the lawn. Will it affect the seed and keep it from germinating? Do I need to wait another year?
A: My bet would be that you probably will need to wait. The weedkiller portion of that product probably has a pre-emergent component to it, and that would keep your ryegrass seed from germinating.
Q: My Meyer lemon tree has survived three hard freezes and has grown to 10 feet tall. I’m
concerned that it will outgrow the space I have for it. When can I prune it?
A: Spring would be best time so you can assess and take into account any freeze damage that it may experience.
Q: I have all Bermuda grass in my lawn. It was planted when the house was new. Much of it is doing OK, but some looks like this (see photo). My lawn care company suggested I put topsoil over the bare areas to get it to fill in. What is your suggestion?
A: Honestly, I don’t believe I ever saw a lawn look like this. It almost looks like frost damage on Bermuda grass. Even the remaining tufts look like they may be dying. For that reason, I would wonder about Pythium blight.
You might want to consult with the Plant Disease Clinic at Texas A&M about running cultures on samples of your grass to see if a disease might be involved. I’m going to need more clues. It’s highly unusual. Adding topsoil is not going to help it at all, however.
Q: We have five crape myrtle trees that we planted along our driveway in 1973. Obviously, they are huge now. We enjoy their blooms, but they seem to come later now, and one of the trees has even died to the ground. We are grooming sprouts from it to become a new tree — we’re happy to see it bloom again. We’d like to cut the others down to match. Is that permissible, or must we dig them all up?
A: Without any photo I hate to take a guess. The generic answer, of course, is that you can cut any dead wood out of any tree, crape myrtles included.
And you could certainly cut all five back completely to the ground and retrain them. That’s essentially what we do when winter kills crape myrtles to the ground in colder parts of Texas. That happens commonly. But that’s really extreme if there’s anything else that can be done to the remaining four trees.
It may be that they only need nitrogen. Nitrogen promotes new growth, and it’s on that new growth that flower buds are formed. Without new growth, no flowers.
Before you go to all that trouble I’d suggest you either have a Texas Master Certified Nursery Professional at a local independent retail garden center or a certified arborist look at a photo of the plants or see them on site.
Q: We have several dwarf pittosporums in a front bed that is shaded in the morning and in full sun all afternoon. Only one has a problem. Should we prune out the dead area or just replace the entire plant? (See photo.) This shrub is the oldest one in the bed.
A: Your last sentence suggests this bed is evolving over time. If that’s the case, I think I’d just prune out the dead portion. I suspect it’s just been broken or damaged in some way. I don’t believe there is an insect or disease that would affect only half of one plant that way, so there is probably nothing to spread to the other plants.
However, Wheeler’s dwarf pittosporums are very small plants. I worry that these will never grow together. You are going to be seeing them as individuals within your landscape for many years.
You might consider digging and clustering them into a natural grouping late this winter, after the worst of the cold and before the new growth begins. It’s just a thought that you didn’t request, so please forgive the intrusion.