Q&A: Vitex needs full sun to bloom each year?

This is an encore column by Robert Stiffler. The following questions originally were published in 1990.

Q. You wrote an article about vitex where you said it should bloom the first year. This is the third year for mine and it has grown well but never bloomed. It has no sign of buds. I bought it as a healthy bush from Thomas Jefferson Gardens at Monticello. Any suggestions?

A. It's unusual for vitex to fail to bloom. Is it on the north side of your house, under an oak tree or in deep shade? It needs full sun to bloom. If your answer is yes to any of the questions above, move it after Oct. 15 into an area that gets full sun and it should bloom profusely.

Peony, azalea problems

Q. I am enclosing pieces from two peony bushes. Neither has bloomed in the last three years but they appear to be very healthy. Can you tell me why they don't bloom?

Also enclosed is a piece of my Coral Belle azalea. It looks like it's dying. Is there anything I can do about either problem?

A. It's not always easy to grow peonies in this area. Authority Andre Viette says they need some shade. At the Experiment Station Arboretum on Diamond Springs Road in Virginia Beach, there is a peony under a tree that looks dead every summer and then blooms profusely in the spring.

Normally, they do not bloom if planted too deep, but since yours had once bloomed, that's not the problem unless you added excessive mulch, causing them to be too deep.

Virginia Tech authorities say that either our winters are too warm or summers too hot for peonies. This causes the plant to weaken and not be strong enough to carry flowers.

Sorry for not having a better response, but about all you can do is feed them this fall and water them during dry spells and hope they'll come back.

When the foliage turns brown, which it usually does by this time of year, prune it off, and fertilize with 8-8-8 or a good bulb food.

As to your azaleas, they decline for many unidentified reasons. I discovered a Coral Belle just this summer that was dying, among a planting of four that were 15 years old. It could be voles eating the roots, diseases or whatever.

Once dieback starts, it's difficult to stop. Your best bet is to yank out any sick azaleas and replace with new ones. October is the best month to plant azaleas in this area.

No flowers

Q. I bought three dogwoods six years ago. They did not grow an inch until last spring. My problem now is that they have yet to flower. I want a flowering tree. Is there something I can do? Cutting them down is a last resort.

A. Many gardeners are impatient with plants that don't bloom. Usually the plant is not old enough. Dogwoods often do not bloom until they're 7 to 10 years old.

Meanwhile, Virginia Tech authorities report that dogwoods will not bloom if under water stress when they set their flower buds in August. If there is a lack of rainfall between July 15 and Sept. 1, you should water them regularly to make sure they get one inch of water per week. If you do that, they'll bloom once they get old enough and have sufficient sunshine.

Remember they like filtered light but need some sunshine in order to bloom profusely.

Ask us No gardening questions are taken over the phone. For a faster reply, e-mail rstiffler@dejazzd.com and include your city. Or, write to Robert Stiffler, The Virginian-Pilot, 150 W. Brambleton Ave., Norfolk, VA 23510. Fax to (757) 446-2963. Limit letters to one or two questions. For an earlier reply, send a self-addressed, stamped envelope.