Q: I’m going on my fourth season, and I can’t get our passion flower to bloom. We have vines galore. I’ve adjusted soil pH, fertilized, watered, trellised and not a sign of a bloom. Any ideas? It gets full sun until around 4.
A: Although passion flower vines can take two to three years after planting to bloom, I don’t think that is the case here. Passion flower acts like the native plant it is, rather than a cultivated garden queen in need, meaning it does better with little care. It seems you have the water and sun requirements about right, and if the soil around the plant is generously mulched, that’s a plus, too. However, you mentioning “fertilizer” and “vines galore” in the same paragraph makes me think way too much nitrogen is the problem.
If you incorporate a generous amount of compost into the planting hole and add more compost as mulch on a yearly basis, passion flower should get just about all the nutrients it needs from the surrounding growing ground. Adding commercial nitrogen encourages strong, impressive leaf growth, but at the expense of bloom production. Still have the need to feed? Skip nitrogen-laced plant foods and opt for a light dusting of phosphorus fertilizer (which encourages flower formation) or occasionally just water with a well-steeped compost tea.
Phlox by any other name
Q: Were the low-growing, spreading lavender/pink flowers that we see in the early spring once called “thrift” instead of “phlox?” I grew up in Wake County in the ’50s and ’60s (and still live here) with parents who were avid gardeners and could swear that phlox was then thrift. You’ve bailed me out before, so I’m hoping you’ve got an answer this time, too.
A: Thrift is a type of phlox, a creeping phlox, actually. A longtime standard in Southern gardens, it is botanically known as Phlox subulata. But if someone points to it in your garden and declares, “Moss pink!” that is yet another old-fashioned name for the same pretty plant. This low-maintenance, drought-tolerant eyecatcher shows off best in full sun or light shade, and when in spring bloom, it looks spectacular dripping off the top of a retaining wall or massed along a steep hillside.
Sprucing up ajuga
Q: I have two very large ajuga beds. The winter has taken a terrible toll on them, and leaves have turned brown and died. Should the dead leaves be picked off? Is there any easy way to do this except leaf by leaf? Should this ajuga be pruned, trimmed or mowed before the growing season?
A: After ajuga becomes established, this fast-spreading member of the mint family can take plenty of abuse. In your case, the plants survived, by Southern standards, a nasty winter (Ajuga is hardy way up to Zone 3 – think North Dakota), but now look like they were worked over with an ugly stick. So, fight abuse with abuse – run the beds over with a lawn mower on a high setting to quickly remove most of the unsightly leaves. Pruning is normally done after the pretty purple flower spikes have shown off in the spring, but if you can’t stand the sight of freeze-damaged foliage, whack away now.
L.A. Jackson is the former editor of Carolina Gardener Magazine. Send your garden questions, including the city where you garden, to: email@example.com.