Calendar for pre-emergents varies across Texas
Q: We applied the preemergent as you recommended last spring. It helped a great deal with this year’s lawn through the summer (until the drought). We intended to apply it again two weeks before the average date of the first killing freeze this fall, as per your book, but we had an early first freeze and never got it down until recently. Have we wasted our money?
A: Please check the dates in my book again. You want to make two applications in late winter and late spring for warm-season weeds (notably crabgrass and grass burs) and one application around Sept. 1 for the coolseason weeds (winter and early spring weeds).
I think where the confusion came in was in the spring applications. The first one, no matter where a gardener lives, should be two weeks before the average date of the last killing freeze for that area. So that’s going to put the application in February for South Texas, early March for Central Texas and late March into early April for the coolest parts of Texas in the Panhandle. The second application would come 90 days after the first (since the pre-emergents are effective about 100 days). The most common products are Dimension, Halts and Balan, and any of the three should do a good job if applied at those times.
Then the third application the last week of August or the first week of September would be for annual bluegrass, rescue grass and ryegrass. They germinate in the fall and become unsightly as spring unfolds. I
can’t speak to how much good such a late application will do. I hope that helps.
Q: This is an unusual seedling that has come up in the middle of one of our oleanders. Should we try to save it? I don’t even know what it is.
A:
I’ve been doing this column for 50 years and I’ve never had this tree sent for identification. You have a Chinese parasol tree (Firmiana simplex). It will grow to 20 or 25 feet tall and wide. As you can already tell, it’s going to have very large, bold-textured leaves.
What will be most dramatic about it, however, will be its green trunks. It can be a bit messy, and seedlings will come up in your and neighbors’ yards just as this one has. This could either have come from another varnish tree in the neighborhood, or it might have fallen into the pot in the nursery where the oleander was grown.
If you do decide to transplant it, you’re going to have to do so with a sharpshooter spade and by digging very carefully this winter. Otherwise, you’ll tear up your oleander in the process.
Q: Last year I had a beautiful poinsettia. After Christmas I put it on the patio, expecting it to meet its maker quickly. However, it survived and has grown. Its leaves are smaller, but they appear to be turning red now. Is there anything I can do to help it thrive?
A:
First, keep it from freezing. If we lived where we could be assured they would never freeze, poinsettias could be grown directly in the ground. In such a setting they would grow to be 8 or 10 feet tall and wide. The larger the plant is, the smaller the floral bracts. However, you’ll also have more of them, so the overall display will be showy if you can keep it
from freezing. Full or nearly full sunlight will also be required. Good luck with it!
Q: Why did my pears, wisteria and Carolina jessamine all have flowers this fall? Do I need to worry about spring blooms?
A:
Those plants typically all bloom coming out of the winter dormant season. Summer also causes them to go essentially dormant for several months (especially this hot, dry summer), so this fall bloom was prompted by the return to good growing conditions. It will have no impact on their spring bloom.
Q: I have seen bay laurel trees grown outdoors in parts of Texas. What is their Hardiness Zone? I have one that my mom raised from a 4-inch pot. It is very special to me. The plant (still in a pot) is getting very large. I’d like to plant it outside if I
can. A:
Bay laurel (Laurus nobilis) is winter-hardy to Zone 8 (southern half of the state, if you go by the 2012 USDA Zone map). That means that it’s vulnerable to temperatures into the low teens, but I’d have protection available for it anytime it drops below 20. February 2021 would have wrecked it in most of the state. Also, if possible, wait until spring so it will have a full growing season to become acclimated.
Q: I have a lovely bed of hardy red hibiscus. I’ve not grown it before. Should I cut it back now that the leaves have turned brown and the stems are bare?
A:
Yes. Its stems have died back to the ground. I always cut mine back to about 3 inches so I can see where they are planted. The garden looks a lot tidier, and that way I don’t start rototilling right through them during the winter. As a forewarning, they will be one of the last perennials to send up new shoots come spring. Don’t be impatient.
Q: I am trying to grow episcias in a bright east window. I’ve tried three or four varieties and none has done well. What is the secret?
A:
They are related to African violets. In fact, they’re often referred to as “trailing African violets.” They need morning sun through an east window, a porous and well-draining potting soil, and constant moisture and nutrition. I grew several in self-watering pots, and they thrived for a good while. Just don’t let them sit in hot sun in the summertime, and don’t let the plants get dry to the point of wilting badly.