Before planting tropical milkweed for monarchs, read this
Q: This tropical milkweed has popped up in my yard. Is it true that it’s bad for monarchs? Should I keep it or remove it?
A: Being a horticulturist and not an entomologist, I thought I’d do a bit of reading on the topic. I rarely post entire URL links in my answers, but this write-up is too good to pass up. It’s an excellent explanation of why we here in Texas should be careful growing tropical milkweed. It doesn’t say that we shouldn’t grow it. It just says that we should prune it back severely a couple of times each year and it explains why.
Note: It was written in 2016, but nothing in it is dated. https://monarchbutterfly garden.net/is-tropicalmilkweed-killing-monarchbutterflies/.
Q: We’ve been gardening for 60 years and this year, for the first time, no tomatoes. The plants are growing well, but no blooms and, therefore, no tomatoes. They are the variety Celebrity as we always grow. Do you have any idea what the problem might be? We did get them planted late.
A:
The late planting did not help since the weather turned so hot so early. There is also a possibility that your garden may have more shade than it has had in the past, perhaps from trees that have grown larger.
If you are growing tomatoes in the same soil year after year, problems like nematodes can build up in the soil. It’s a good idea to move your crops around. Farmers refer to it as “crop rotation.”
I guess it’s also possible that your plants were mislabeled at the nursery, although you would expect any tomato variety, mislabeled or otherwise, at least to bloom. Beyond that, I really don’t have any other brainstorms. If it’s any consolation, a couple of my veteran gardening friends have reported similar experiences this spring.
Q: Something is attacking and killing the potted plants on my porch. What is it, and
what is the treatment? A:
These are mealybugs. As insect pests go, they are among the most obnoxious. They are soft-bodied scale insects. They migrate in their younger stages, attach to the plants’ stems and leaves, and then suck the sap out of the plants’ tissues.
Some types of plants are
extremely vulnerable, for example, coleus and plumerias and other succulents. They are generally a more serious problem on plants indoors or in greenhouses, but they will occasionally show up on plants in flower beds.
If you have only a few mealybugs, you can generally use a
cotton swab dipped in rubbing alcohol to eradicate them. For larger populations, however, you will need to use a properly labeled insecticide. It almost always takes several applications on two- or three-week intervals to get rid of them. My best advice is don’t let them get started.
Q: My red oak’s trunk has a large crack. What should I do to it?
A:
First and foremost, have a certified arborist look at it closely and examine it for any signs of active decay. Many Texas live oaks and red oaks suffered serious damage from the cold of February 2021. Known as “radial shake,” the damage took the form of vertical cracks in the bark that subsequently popped open to expose internal wood of the trees’ trunks. That’s probably what has happened here.
Hopefully it’s only in this one spot, although I see bark to the left that looks like it also might be impacted. Don’t pull on bark, however, to see if it’s still attached. It will let you know early enough.
If the loose bark extends no more than halfway around the trunk, the tree will likely be able to recover and grow new bark across the wound. Hopefully, that will begin soon. That’s one of the things for which the arborist will be looking.
Beyond that, there isn’t anything you can do except wait.
Q: We built a rose garden last winter and planted seven roses. They bloomed beautifully this spring, but today the plants are spindly and have yellowed, blotchy leaves. I don’t know what to do. Any advice?
A:
A photo would have helped, but please Google “photo roses black spot.” I suspect the fungal disease has knocked the leaves off your plants. It hits in the cool, moist days of spring. The leaves develop yellow blotches with dark brown or black spots. Infected leaves soon drop leaving the plants almost completely bare.
If that’s the case, your best bet is to trim them back by 30 to 35 percent and start a weekly spray program with any fungicide labeled for control of black spot. Next time, look into the Texas A&M Earthkind roses that have been shown to be almost bulletproof against the disease.
Q: We have 1,000 square feet of St. Augustine in our backyard. We are going to be away for 16 days. If we water it really well before we leave, will it survive? It’s been planted for 14 months. Do we need to have someone water it?
A:
Have someone water it. That’s too long to be without. Be wary, too, of chinch bugs. This is prime time for their attacks, and if the grass is in a sunny location, you could come home to brown turf.