Dear Neil: Several months ago, you recommended a fungicide for yellowing and dying photinias. Could you please repeat it?

A: It would have been Daconil, but as good as it is, it's no match for that disease. Entomosporium fungal leaf spots start out as small maroon freckles over the leaves of photinias (and, to a lesser degree, Indian hawthorns). The next thing you'll see with redtips is yellowing of the leaves in random portions of the plant. Over the ensuing months, the affected plants will weaken and turn brown and then leafless. It is such a virulent disease that most landscape contractors no longer use redtip photinias. Once the disease moves in, it's almost impossible to turn it around. You're better off replacing the plants with Nellie R. Stevens hollies or some other size-appropriate plant.

Dear Neil: Is there anything we can put on our "pink" pampasgrass to get it to turn really pink? It's more beige than pink right now.

A: A century ago, pampasgrass was quite the rage for floral designs. Many colors of plumes were selected by natural mutation, but they all leaned toward the original buff color, just as your pink type does. Unfortunately, fertilizer alone won't make any difference in the plumes' color. If you want a truly pink-flowering grass, choose "Regal Mist" gulf muhly.

Dear Neil: Over the past two years, large portions of my St. Augustine lawn have died. It's not in the circular patches that are typical of Take All patch. The grass didn't die first. It just faded away. But the patches are only in shaded areas near the trees. Grass grew there before. How can I resod the area?

A: Slow down. Take All patch causes irregular thinning and dying of grass in both sun and shade. Brown patch is the autumn disease that causes St. Augustine to develop round, brown patches. It, too, will be in sun and shade. What you're describing is excessive shade, pure and simple. St. Augustine requires four hours of hot, direct sunlight all season long. As trees grow, the shade exceeds those limits, particularly near the trunks. Planting new sod would be a waste. Go with a shade-tolerant ground cover such as mondograss, liriope, purple wintercreeper or Asian jasmine. Prepare the planting bed carefully prior to setting them out.

Dear Neil: I have a beautiful hibiscus plant that has grown quite large. Can it be trimmed? If so, when and how? It's still blooming, and I don't want to ruin it.

A: If you're talking about a tropical hibiscus, you'll need to do something as you get it ready for the winter. You can certainly trim it as needed to shape and to fit available space. The critical issue is that it have full sunlight all winter. If you're talking about hardy hibiscus (mallows), the first freeze will kill the tops to the ground. New shoots will emerge in mid-spring for next year's blooms.

Dear Neil: I have a wild grass in my St. Augustine. I've tried several weedkillers, and it's still alive. What can I do?

A: Be really, really careful. There are no post-emergent grass killers that will selectively kill weedy grasses in St. Augustine without killing the St. Augustine first. Luckily, other than nutsedge and dallisgrass, St. Augustine is vigorous enough that it should crowd out all other invading grasses. If you have nutsedge, use Image during the summer. If you have dallisgrass, hand-dig or spot-treat with a glyphosate herbicide.

Dear Neil: I bought a potted Plectranthus plant about this time a year ago. It did fine indoors over the winter, but now, a season later, it appears to be dying back in spite of being watered properly. Is this a plant I can keep indoors, then outdoors for years, or do I need to buy another?

A: You didn't mention which type you have -- there are many species and varieties of Plectranthus. Many will play out after that many months. Try rooting cuttings if your plant still has enough vigor. Otherwise, they're fairly common and inexpensive in nurseries.

Dear Neil: I purchased one of Dr. Buck's roses. I was encouraged that it would be heat-tolerant and drought-resistant as well as relatively pest-free. However, it has failed miserably, while cheap plants from a discount store have flourished. Where did I go wrong?

A: Some of the best minds in rose-growing, dating back to Dr. Buck's research decades ago in Iowa, have studied his roses alongside other recognized varieties. They, along with the other Texas A&M EarthKind roses, have proved their superiority. You were unlucky with your Buck rose, and you were very lucky with your bargain plants. Most people have just the opposite results.

Dear Neil: Can I trim neglected nandinas? If so, when and how? What fertilizer would be best for them?

A: Cut lanky nandina canes back to the ground in the winter. New shoots will develop rapidly from the crowns of the old plants. Trimming higher will result in distorted, unnatural plants. Use an all-nitrogen fertilizer in late winter to promote vigorous new shoots in the spring.

Dear Neil: What is the best lawngrass for an urban landscape? How do I convert from an existing lawn that isn't especially vigorous?

A: Many Texans find that common bermudagrass offers the combination of good looks, durability, pest resistance and vigor. Its main shortcoming is that it is intolerant of shade. Others prefer the brighter green of St. Augustine. While it tolerates shade much better than other grasses, it still requires at least four hours of sunlight daily. Both grasses can be sodded, although it's getting late to do so. St. Augustine is the dominant grass among all of our turf types, so it can also be plugged into the existing lawn and allowed to spread and overtake it. You would need to do that after mid-spring next year.

If you'd like Neil Sperry's help with a plant question, drop him a note in care of The Eagle, P.O. Box 3000, Bryan, Texas 77805. Or e-mail him at mailbag@sperrygardens.com.

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