Dear Neil: What is this weed that is taking over our neighborhood? It’s incredibly difficult to pull out.
A: This is roadside aster, and it seems like it’s going to keep blooming forever this fall. Someone asked about it back in September, and here we are a solid two months later. It’s actually a broadleafed weed, meaning that it’s not a grass. Therefore a broadleafed herbicide containing 2,4-D will eliminate it. However, it’s too late to be spraying now. It’s going to die out in the cold weather, if it hasn’t by the time you read this. Your approach next year should be to fertilize and water your lawn just a bit more aggressively. This is a weed that normally shows up in parts of our turf that are a little too dry or a bit on the “hungry” side. Because its leaves are so small, we hardly notice it all summer, but then it puts out these small, daisy-like blossoms come fall and everybody notices it. If you see it growing in the summer, you can spot-spray to eliminate the rogue plants, but stepping up the maintenance of your lawn will usually be all that you’ll need to do.
Dear Neil: If I want to use Nellie R. Stevens hollies to make an 8-foot-tall screen, how far apart should I plant them?
A: My rule of thumb is always to plant screening shrubs two-thirds as far apart as I’m going to allow them to grow. So using that ratio it would be 6 feet apart. However, there is a better holly in that size range. Go with Willowleaf (also known as “Needlepoint”) holly. Their mature height is 10 or 12 feet, so maintaining them at 8 feet will be a lot easier than it will be with Nellie R. Stevens. If not trimmed, they can grow to be 16 to 18 feet tall. Plant Willowleaf hollies 6 feet apart and they’ll be fine.
Dear Neil: Nothing looks much worse than cannas after they freeze. Do I need to put mulch over them for the winter?
A: No, although a loose organic mulch such as shredded tree leaves never hurts. Trim the frozen tops off before you rake out the mulch, just to keep the bed looking tidy.
Dear Neil: I’m very familiar with the cane you see in roadsides in many parts of Texas. However, this fall I saw a planting that looked like a variegated form. Would that be suitable in a home landscape? I have a large backyard, and I really liked the look.
A: Yes. I know of a couple of plantings of it near where I live. I’ve watched them for 40 years, and they’ve been very pretty. I will warn you that it does tend to revert to the solid green form, or at least those plantings have done so. Keep the green sprouts trimmed out. Thank heavens it’s not as invasive as golden bamboo. There’s another fact that blew me away a year ago. We have a granddaughter who plays bassoon. She took a reed-making course, and in the process of all that I stumbled across another name for cane: “bassoon cane.” It’s what musicians use. They harvest it, dry it for a prolonged time and then fashion their reeds from it. (That’s as much as a horticulturist can tell you about it. I’ll let you do further research if you’re interested.)
Dear Neil: I had Andorra juniper as a groundcover at our house in Illinois. How well does it do in Texas?
A: Average or below. For those who aren’t familiar, it’s a very pretty trailing juniper that turns maroon in the cold weather of winter. However, it requires perfect drainage, or it will die out. Bermudagrass invades it and is almost impossible to remove. And spider mites get into it from late winter into the summer and ruin it before you’re even aware. If you like that purple cool-season color, purple wintercreeper euonymus is a better choice.
Dear Neil: I have a large night-blooming cereus in my greenhouse. It really needs to be repotted. What kind of potting soil would be best, and when should I repot it?
A: Like its somewhat distant cousins Christmas cacti, night-blooming cereus needs very loose, highly organic potting soil. That would simulate what it would find growing in the crotches of tree limbs in nature. I use a mixture consisting of 50% sphagnum peat moss, 20% finely ground pine bark mulch, 10% perlite and 20% expanded shale (mostly for ballast). You can repot them at any time. If your greenhouse has good lighting and if you keep it fairly warm (55 or 60 or warmer), you could repot it right now. Otherwise, wait until early spring.
Dear Neil: I was told that I can root mother-in-law plants from their leaves. Is that true?
A: Yes, but your success depends completely on the variety. We’re talking about sansevierias. Those that are either green or variegated randomly all over will reproduce true to form when rooted from leaf cuttings. However, those that have leaves with stripes running up the edges of their leaves will not. Those are known as chimeras, and they will be variegated depending on where the new plant forms. They may be all green, half-and-half, or all yellow or all white. Those that have primarily yellow or white tissues will not have enough chlorophyll to survive, and they will eventually die. To root a leaf cutting use a sharp knife to cut the leaf into sections about 3 inches long. Be sure you know which part of each cutting was the top originally. Stick the cuttings into a pot filled with equal amounts of peat moss and perlite. Stick each cutting halfway down (tops up!) into the mix and keep the mix moist until the cuttings form roots and send up shoots.
If you’d like Neil Sperry’s help with a plant question, drop him a note in care of The Eagle, P.O. Box 3000, Bryan, Texas 77805. Or email him at email@example.com.