Neil Sperry's Mailbag

DEAR NEIL: What is wrong with our ivy? I've lost a 50-year-old planting, and my son's plants have died, too.

You are not alone! English ivy and other related ivies struggled mightily with last spring's and summer's continued rain and saturated soil. Plants that were growing in heavy clays lost the battle, and many of those old plantings are still dying. I have lost a large groundcover bed as well as the ivy growing up two tree trunks. Drenching the soil with a fungicide helped temporarily, but I grew weary of that responsibility and have switched over to other shade-tolerant groundcovers such as mondograss, liriope, ferns, Asian jasmine and purple wintercreeper euonymous. This has been a difficult problem to manage. My guess would be that you're better off changing.

DEAR NEIL: We have a St. Augustine lawn that has been infested with crabgrass. The problem is increasing. In some areas, it's just individual clumps. In other areas, the crabgrass is almost solid. What can we do?

I am going to give you three distinctly different answers, and I'll explain why. First, you should not see true crabgrass in a St. Augustine lawn. St. Augustine is the dominant grass of the two. If crabgrass is showing up, you need to step up the maintenance of your St. Augustine and the crabgrass will not return. Second, if you do have crabgrass in a lawn of any type of turf, you can use pre-emergent weedkiller granules to prevent its germination in the first place. That application should be made March 1, with a repeat "booster shot" treatment 90 days later. Third, and most likely, you probably don't have crabgrass at all. If the weed is very dark green and forms dinnerplate-sized clumps, you probably have dallisgrass. Dallisgrass is a perennial weed. It comes back from its roots and is even visible during warm winter spells. Crabgrass is an annual that has to start its life cycle over each year. You can further confirm the identification by watching the seedheads this summer. Crabgrass heads look like helicopter rotors.

Dallisgrass heads form just a day or two after you mow, and they resemble old-fashioned telephone pole crossarms. The seeds are small green disks with black, peppery specks hanging from them. Dallisgrass in St. Augustine is a difficult problem. There is no spray that will kill it without killing your turf. Spot-treat with Roundup, or dig it out with a sharpshooter spade as soon as you see it.

DEAR NEIL: If I wanted to divide monkeygrass to line my sidewalk, what size of clumps should I dig, and when is the best time to do it?

Mondograss (a.k.a. monkeygrass) can be dug and moved at almost any time of the year. Late winter and early spring are very good times, as the plants quickly reestablish in their new homes. Tennis-ball-sized clumps that you plant on 8-inch centers will give you a quick fill. Plant them closer together if you're planting on a slope. For the record, you'll want some type of barrier such as metal edging driven almost all the way into the ground to keep your mondograss from spreading into your lawn. Be sure, too, that you do actually want to line your bed with any plant. That will draw a lot of attention to the walk, when it's usually better to draw attention more toward the front door itself.

DEAR NEIL: Last year bermudagrass invaded my St. Augustine. When should I apply a pre-emergent for it?

Pre-emergent weedkillers work only on annual plants. Bermuda comes back from its roots and runners. Adding further to your problem, anything that kills bermuda will also kill St. Augustine. The good news is that if you take better care of your St. Augustine in terms of mowing, watering and fertilizing it, it will crowd out almost all grasses, bermuda included.

SPERRY
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