Trim butterfly bush in late fall
Dear Neil: My butterfly bush has produced long stems that have spread out from its base. How and when do I trim it? Do I cut off the dead flowers?
Answer: Butterfly bush (Buddleia) is somewhere between being a shrub and a perennial. As such, it takes on the looks of a shrub, but you maintain it pretty much like you would a perennial. Trim its tall stems back to within 6 to 8 inches of the ground late each fall. That will keep it from getting too leggy the following season. Of course, in doing so, you’ll be removing all the old flowers.
Dear Neil: We live in an area with really sandy ground that is covered with sticker burs. How can we eliminate them?
A: Grassburs, or stickers, can be prevented by applications of a pre-emergent weedkiller in mid-March and again in mid-June each year. These products are safe on any lawngrass (so long as it is well-established), and they can be used around trees and shrubs. They form a barrier on the surface of the soil through which weed seeds will not germinate (hence the name pre-emergent). If you miss the timing, or if you still get some limited germination, you can use MSMA on Bermuda turf to kill existing grassbur plants. That product cannot be used on other types of turfgrasses. June and early July would be the timing for that treatment (certainly not this late in the season), but the pre-emergents are the better option.
Dear Neil: I have enclosed a branch from a shrub that I keep trimmed down to 4 feet. It has flat branches, as you can see. I am wondering how tall it would grow if I let it go without trimming. What is it? No one else in our neighborhood has one.
A: This is Amur River privet, a sister to Japanese and waxleaf ligustrums. It sprouts freely from its seeds, so you can expect to see scores of them in your own yard and around the block. Privet was the favored hedge shrub 40 and 50 years ago, and a few people still have it. More commonly, you see the variegated form of it in many landscapes. Gardeners often trim it, also, back to 4 or 5 feet. Both plants would grow to 8 to 15 feet if left untrimmed. They actually are rather pretty shrubs when grown that way, but they’re maintenance chores if you try to keep them short. For the record, you don’t see fruit as often on the variegated form, but it does tend to revert to the green parent rather freely. If you ever used that one, you would have to keep the green growth trimmed out or it quickly will overtake the less aggressive variegated branches.
Dear Neil: When do nurserymen take their crape myrtle cuttings? I’ve heard several different opinions. I want to start some new plants of my own.
A: Most growers prefer green “softwood” cuttings taken in May and early June. It roots quickly, plus the plants have ample time to develop good root systems before winter. You also can root hardwood cuttings in late winter, just before the spring growth begins, but the results are not nearly as predictable.
• If you’d like Neil Sperry’s help with a plant question, drop him a note in care of The Eagle.