Q: Our condominium complex has a terrible mosquito problem. What do you think of installing purple martin or bat houses?

Nellie Holleman, Atlanta

A: Neither bats nor martins control mosquitoes. In the case of martins, the mosquitoes don't offer enough protein to make it worth the bird's while to catch and eat them.

In the case of bats, mosquitoes don't fly up high where bats like to swoop chasing moths and beetles.

The best way to control mosquitoes is to eliminate standing water. Also consider installing pedestal fans near outdoor gathering areas to blow mosquitoes off course.

Q: The bark is splitting and falling off our 3-year-old crape myrtle tree. What can I do?

Diane Chumbley, e-mail

A: This is normal, desired behavior for a crape myrtle. It's called bark exfoliation. This characteristic comes by way of the crape myrtle breeding program of Don Egolf. He crossbred Indian crape myrtle, Lagerstroemia indica, which has pretty flowers, with Japanese crape myrtle, Lagerstroemia faureii, which resists powdery mildew and has a sinuous trunk character.

My "Natchez" crape myrtle exfoliates every June to reveal a smooth, cinnamon-colored underbark.

If you don't like the look of the bark peelings, you can remove them once they're completely free from the trunk.

Q: My landscape company laid 6,500 square feet of "Zenith" zoysia sod in early June. The irrigation company then installed a five-zone sprinkler system.

The irrigation folks suggested running the zones full blast each day when I can water. My water meter says I'm using just over 4,000 gallons per watering. I'm afraid I may be killing the sod with 12,000 gallons per week.

Dick Kretzmer, e-mail

A: Yes, I think you're overwatering a bit.

A new sod install needs 1 inch of water per 1,000 square feet immediately. One inch of water is 600 gallons. Multiplying 6.5 times 600 gives us 3,900 gallons per watering. This is pretty close to 4,000 gallons your meter indicates. However, you only need to do that one time.

After the initial soaking, your job is simply to keep the sod moist until it roots into the underlying soil — perhaps one-quarter to one-half inch at a time.

If you continue to put down 12,000 gallons per week, root rot will overtake your zoysia grass. Sod watering details at http://xrl.us/WATERSOD.