Q: Four of our 14 Cleveland pear trees have been killed by ambrosia beetles. Can we replant this late in the spring?Sheila Jordan, email

A: You can plant trees now but let me urge you to plant something other than flowering pear. 'Cleveland Select', 'Aristocrat' and 'Bradford' pear produce sterile seed when grown far from each other. But when two or more varieties of flowering pear grow nearby, they definitely can pollinate each other's flowers. Each tree will then produce lots of little brown fruit with seeds inside. The seeds are scattered by chipmunks, birds and other creatures. The resulting plant is a vigorous bush with menacing 3-inch thorns. It spreads like wildfire through natural areas. It is extremely difficult to control except with machinery. Because of this environmental threat, I have stopped recommending flowering pears for landscapes. 'Natchez' crapemyrtle, redbud, or saucer magnolia would be good substitutes.

Q: How short should I cut my bermuda sod before it starts to green?Billy Patrick, email

A: Set your mower height one notch lower than you typically use. Mowing now will remove most of the brown foliage and expose the crown of the grass to sunshine. Your lawn will be greener one or two weeks earlier than your neighbors'.

Q: My car would not start one morning. When I opened the hood there were acorns on top of the engine and nearby wires were obviously chewed through. What do you think did it?Bobbie Fuller, Chamblee

A: I offer up three suspects: squirrel, rat, or mouse. Each of them will collect and feed on acorns. Why they chose the top of your engine for a dinner party is an open question. There are no effective repellents for these creatures, and I can't think of a way to exclude them from your car, so I suppose trapping is the remaining option. All can be captured in a humane cage trap baited with peanut butter. Buy a model with wire mesh small enough to hold a mouse.

Q: I am going to be installing zoysia sod soon. My lot is heavily shaded but I'm having my trees thinned to help with sunlight. The soil stays a little damp. Would it be good to put down three to four inches of sand before laying down the sod?John Elliott, email

A: You run a big risk of wasting a lot of money. Putting a layer of sand underneath existing soil is not a good idea. Grass roots do not easily grow through soils of different coarseness. Uneven drainage and uneven drying would far outweigh any advantage to having a sand layer. Your contractor can advise on tilling in materials to help your existing soil drain faster. Anything added needs to be mixed with existing soil at least eight inches deep. Zoysia sometimes tolerates a bit of shade but I’ve never seen it do well for long under limb-thinned trees. A tree will produce new limbs and equal shade in just a couple of years after thinning. Zoysia needs at least five or six hours of direct sunshine to thrive and combat weeds.