Dear Neil: I have a three-leafed vine growing in my Asian jasmine. It has smooth leaves, so I don’t think it’s poison ivy, but I’m not pulling it anyway. Is there a spray I can use to kill it that won’t hurt the jasmine?
A: Probably not. Any herbicide that would kill the mysterious vine will also kill the Asian jasmine. You might try spot-treating the weed with a broadleafed weedkiller containing 2,4-D applied carefully with a foam rubber paintbrush. However, you won’t get very good control in the fall. Late spring is the better time. Honestly, if this were my problem I’d probably use an asparagus knife to sever the weed. I’d wear gloves and a long-sleeved shirt just to be on the safe side, then scrub up immediately after you’re finished.
Dear Neil: How tall will waxleaf ligustrum grow? I need a privacy screen, but I don’t want something more than 8 or 9 feet tall.
A: Waxleaf should be around that height with very infrequent pruning (every few years). Willowleaf holly (also known as Needlepoint holly) is of about the same size. It is better suited to partial shade than the ligustrum if that’s of any concern. It’s also more winter-hardy in colder areas, but both are good screens. Just be sure you don’t accidentally end up with Japanese ligustrum, often called glossy privet. Because it sets fertile seeds, it is horribly invasive.
Dear Neil: I have compacta nandinas across part of one side of my house. I have another area where I’d like to grow them. My plants have lots of berries. Can I grow them from seed?
A: The seeds will sprout and produce nandinas, but they probably won’t “come true” as more compacta types. You’re likely to get a fairly wide range of heights in the seedlings. Compacta nandinas send up many new shoots. It’s easier just to dig them and divide them somewhat like you do perennials. I’ve started several new beds at our home quite successfully that way. By propagating asexually (without involving seeds), all of your plants are genetically identical.
Dear Neil: We have St. Augustine growing beneath oak trees. This time of year we have a lot of leaves falling to the ground. Is it good to mulch those leaves into the soil? They really seem to add up.
A: That’s probably too much of a good thing. I suggest catching the clippings for the busiest weeks of leaf drop season and putting the shredded clippings into the compost pile or at least into use as a garden mulch around shrubs or in the perennial garden. If you return that much organic matter to the soil all at one time it will probably choke out the grass.
Dear Neil: What should I do with an asparagus bed in the winter? We just moved to a house where the prior owner had a 15-foot row of asparagus across the back fence. It’s been really pretty all summer, but now it’s starting to turn yellow.
A: Asparagus is a perennial vegetable that will die to the ground with the first freeze. As with many perennials, its stems and leaves start turning yellow, then brown as the days grow shorter. Once they’re completely finished you can cut them off just a few inches above the ground, especially once they’ve been exposed to a hard freeze. I leave a few inches of stem in place so I can see where the roots are over the winter. That shows me where I want to apply an all-nitrogen fertilizer in late January to start a flush of new growth for spring.
Dear Neil: Can I dig and divide monkeygrass this late in the growing season? I have a slope that seems to be eroding. It’s very gentle, but I’m noticing some channels in the soil. Do you have any suggestions of how best to plant it?
A: It’s almost never too late to plant it (unless the ground is frozen). This presumes the area is in a shaded setting. (Mondograss, also known as monkeygrass, doesn’t do well in full sun.) I have used it in exactly the way you have described. I plant it into beds to which I’ve added 1-2 inches of finely ground pine bark mulch rototilled in to a depth of 4 or 5 inches. I don’t go to a lot more trouble than that because whatever I add will eventually decay and be gone anyway. I’m just trying to give the mondograss a bit of a head start.
I plant fist-sized clumps of mondograss on 8-inch centers across the entire bed, checker-boarding them for quickest cover. Their leaves arch to touch from one clump to another, so the visual impact as you stand off to the side is of an almost solid groundcover from the outset. I keep my new beds moist at all times and they are usually grown full within just 12 months. And yes, you can begin all of this now.
Dear Neil: Can I reduce next year’s fall webworm population significantly if I pick up all the webs that are falling to the ground now and send them out with the trash?
A: It might help a bit, but probably not much. Fall webworms are the larvae of moths that are actually quite mobile. They’ll fly in from fair distances to find your trees even if you pick up all that have been on your property this year. But your place will certainly be a lot tidier for your efforts.
• 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.