Corsican mint scorched by the dry days of summer

Q: Here's a burning question. Literally. Last August a lot of my beautiful Corsican mint browned up and died off. It's regrown between my pavers, but I'm afraid what might happen this August. Any suggestions for keeping it green?

A: Mentha requienii, called Corsican or creeping mint, the original flavoring for the drink crème de menthe, grows slowly to form a green, lavender-flowering mat, tolerates some foot traffic and is wonderfully aromatic. Mints rarely have pest or disease problems, prefer full sun and love plenty of moisture, so my guess is that your mint didn't receive sufficient water last summer.

It is easy to be fooled into thinking plants are watered by misty mornings and overcast afternoons, but roots remain dry in these familiar conditions. Try watering often enough to keep the soil slightly moist, and Corsican mint should stay green through the dog days of August.

Q: I have a trumpet vine that hasn't bloomed in 10 years. It has lots of healthy leaves but no flowers. Are there kinds of trumpet vines that never flower?

A: Your trumpet vine is probably Campsis radicans if it has lived for 10 years outdoors in Seattle. (Common names can be confusing — Distictis lactiflora, native to Mexico and so not hardy in our climate, are also called trumpet vines.)

Your vine should bear showy orange-red tubular flowers in late summer. If you prune it back early in the spring, water regularly and give it full sun, the only thing I can think of is that it doesn't get enough heat to bloom. Try moving it to the warmest place in your garden, such as against a south-facing wall, and you might dose it early in the season with a fertilizer high in phosphorus to promote flowering.

Valerie Easton also writes about Plant Life in Sunday's Pacific Northwest Magazine. Call 206-464-8470 or e-mail planttalk@seattletimes.com with your questions. Sorry, no personal replies.