Not all St. Augustine varieties are equally hardy
Q: This looks like Virginia creeper, but the flower is wrong. It has recently shown up in my St. Augustine. How can I get rid of it without hurting the St. Augustine?
A:
This is called dayflower, a relative of wandering Jew. As luck would have it, it’s a relatively weak weed against St. Augustine.
You could use a broadleafed weedkiller spray to control it. Apply it from a trigger bottle or a tank sprayer (not a hose-end sprayer) for the most precise distribution. Apply it soon, while evening temperatures are still below 88 degrees, and do not apply it when the sun is hitting the St. Augustine directly. The label will explain the precautions to avoid any burning of your St. Augustine.
It appears that your St. Augustine is healthy. Keep the grass vigorous, and it will crowd out both the dayflower and the bit of Bermuda that is co-existing with it.
Q: My downspouts have washed away soil and turf grass (Celebration bermuda) in my backyard. I’m going to redirect the water flow to the street. I understand that adding soil is not the answer, but how can I hide all these roots?
A:
This is a really unusual situation. I’ve been sent probably thousands of sets of photos of tree roots on top of the ground over the past 47 years, and yours are among the very few where there has been real erosion. I can see that in the sandy soil piled up against the side of the fence.
My first suggestion is going to be that you find a certified arborist or a veteran landscape contractor (or, better yet, both) to discuss this situation with each other and with you. The eroded soil needs to be removed from its position against the fence and returned to its original home, wherever that might
have been (probably on the other side of the trunk). If that exposes more roots in the process, do it anyway. If it’s going to expose a lot of roots, perhaps wait until October, after summer’s hot weather.
Next, talk to the arborist about which roots can be removed entirely. Hopefully, it will be all of them. Sure, the tree needs them, but you don’t
want roots above grade. Encourage the tree to develop deeper roots by keeping it watered deeply and by removing surface roots that could trip pedestrians. They can also push up fences and break sidewalks. The arborist will be the person to hold your hand through all this.
If you have bare ground and you need to stop erosion, use
green liriope beneath the tree (for shade) and purple wintercreeper euonymus for sunny spots.
Q: I’m asking about St. Augustine along the Red River near Wichita Falls. I know winter and last summer’s drought were hard on the grass, but my neighbor’s lawn looks great compared to mine. We do use different lawn-care companies. Could the Dimension that was applied to my lawn in early April have hurt my grass? (My lawn is on the right in my photo.) Otherwise, the lawns are cared for almost identically.
A:
I don’t believe Dimension would harm your St. Augustine. It is labeled for use on any existing turf. That is, however, verging on late to be applying it, even as far north as you are, but that’s not a factor in this discussion.
Things I would investigate include the variety of St. Augustine each of you has in your lawn. I have Raleigh, and I have found that it is slightly less cold-hardy than some of the others. Palmetto is written up as being slightly tougher against cold. That could be a difference. And it’s an odd observation, but I see a lot of mineral staining on your neighbor’s fence and not much on yours. That would be from irrigation water. Is there a chance that your neighbor is watering more than you are at critical times? Check timings for chinch bug treatments, since they were such a huge problem last year.
Hopefully, in all that you can find the beginnings of an answer.
Q: You suggested to a reader that they “water deeply” and “regularly.” Please explain how we can quantify each of those terms. Also, where can I find an “allnitrogen” fertilizer?
A:
When you use terms for years, you begin to take shortcuts in saying, and writing, them. That’s what I obviously did in that answer.
“Watering deeply” refers to soaking the soil to a depth of 12 to 15 inches. That may take several hours, and it is best accomplished using a soaker hose coiled in large circles around the drip line of the tree. The drip line is the outer canopy of the branches. (Think of the outer edge of an umbrella.) Lay the soaker hose around that drip line in spirals 15 to 18 inches apart. The next time that you water (perhaps 10 to 14 days later) repeat the process, but try to put the hose in a slightly different configuration.
As far as the fertilizer is concerned, most nurseries, hardware stores and feed stores will offer one or more fertilizers that contain only nitrogen. They will also be able to show you one or more that contains a substantial amount of that nitrogen in slowrelease form. I’m going to let them explain the small print on the label and how they identify the difference.