NEIL SPERRY Gardener's Mailbag

Dear Neil: Last year I had trouble with my tomato plants on my patio. The fruit turned black at their ends and were unusable. I don’t want that to happen again. What can I do to prevent it?

A: That was a physiological disorder called blossom-end rot. As water is transported through the plant from the roots to the fruit, the far end of the tomato will be the last place to receive the water and the first place that dries out. Fruit doesn’t wilt like leaves will do, but it will suffer the same kind of “scorch” as the leaves do when they’re dry, and that’s what you saw. It’s imperative that you not let the plants wilt badly between waterings. It’s best to grow tomatoes in at least 7-gallon containers. Larger 10-gallon pots are better still. You’ll see references that call for addition of calcium to correct the problem, but in my experience that has never helped nearly as much here in Texas as maintaining a uniform moisture supply.

PEACH LEAF CURL

Dear Neil: Why are some of the leaves on my peach trees crinkled up and distorted? It almost looks like what a weedkiller would do to them.

A: That’s peach leaf curl. It hits the trees in early spring and is gone by early summer. Those leaves will drop and the growth from now on will be normal. It really doesn’t do much damage, and the only spray you might have made to lessen it would have been made just after leaf drop last fall to kill the overwintering phase on the branches. Just move on. Your trees will be fine.

CROSSANDRA CARE

Dear Neil: I’ve been given a crossandra plant. How should I care for it?

A: This is one of the nicest flowering container plants that we have. Give it a bright east window or a shaded patio. Keep it moist at all times, but be careful that the pot doesn’t stand in water if you have it outdoors. The flower spikes will keep producing blooms for many weeks, even months if you care for it properly. Even its foliage is attractive. Of course, as with most flowering potted plants, it will run its course, but in the meantime you should have a lot of enjoyment. It’s like a scoop of orange sherbet on a warm summer day.

DON’T CHANGE CUTTING HEIGHT

Dear Neil: My son is trying to convince me to raise my lawnmower blade for the summer. He says it will help my grass survive with fewer weeds. Is he correct?

A: Not in my opinion, and not in the opinion of turf experts I’ve asked over the years. This subject has come up relative to water conservation, too, and it’s not accurate there, either. When you mow grass at a height taller than the recommended mowing height it will become thin as it “reaches” for light. Thin grass gives weeds more room to develop, and it also allows the sun’s rays to hit the soil directly. The best thing you can do for your lawn is to determine its optimum mowing height and then stick to it 12 months a year.

PLANTING MAHONIA

Dear Neil: I really like the leatherleaf mahonia plants I have in my shade garden. They’re prickly as can be, but I have them planted out of the way. Is it difficult to grow more from the fruit they have this time of year?

A: Not at all, although you do need to get there ahead of the birds. Harvest the fruit as it turns dark blue and begins to soften. Plant them into 4-inch pots filled with loose, highly organic potting soil and keep them moist as they germinate over the ensuing 4 to 6 weeks. They will grow rather slowly at first, but by this fall you should be able to pot them into 1-gallon pots. They should be big enough to plant into your landscape within 18 months. I’ve grown this plant for 40 years and I share your enthusiasm for it.

Have a question you’d like Neil to consider? Mail it to him in care of this newspaper or e-mail him at mailbag@sperrygardens.com. Neil regrets that he cannot reply to questions individually.