Annual bluegrass should be treated in the fall, will die out in Texas heat

Dear Neil: I have this really fine “winter” grass that stays less than 5 inches tall. It has dozens of little seedheads. I’ve been trying to pull it up, but there is so much of it. What is it, and how can I deal with it?

You have annual bluegrass, or Poa annua. It’s come up here a few weeks ago, but so many have asked about I decided to bring it back. It’s a cool-season annual weed, which means the only thing you can do is to apply a pre-emergent herbicide before it starts to grow. Timing for that is the last week of August through the first week of September. Apply Dimension, Halts or Balan granules following by a general watering at that time to prevent germination of the seeds. There is no way to eliminate the plants once they start growing in early fall. Just wait it out now. It will soon die in the heat of late April and May.

Dear Neil: I have two yaupon hollies that are a couple of years old. One is deep green and the other is yellowish-green. Does color mean anything other than lack of something? I’ve attached a photo showing both plants.

The plant with the yellowish-green leaves has apparently struggled just to get started. It’s been in the ground long enough to benefit now from application of an all-nitrogen fertilizer just as you would give your turfgrass, as well as an ample and ongoing supply of water from now until fall. You might even try one application of a high-nitrogen, water-soluble plant food for even quicker results.

Dear Neil: I have a 100-year-old historic house with several trees around it. I’ve been unable to get grass to grow. Some folks say there is a fungus raging. Others tell me it’s too shady and that I need to plant a groundcover. Still others tell me I should till up the area and bring in new soil – that it will grow back. What can I do that won’t break the bank?

Without a photo I can’t be sure, but I would doubt that it is caused by a fungus. I get this question many times each week (and have for decades), and it’s almost always due to lack of sunlight. St. Augustine is our most shade-tolerant turfgrass, but even it requires 5 or 6 hours of direct sunlight daily to hold its own. I have a great deal of shade at our house due to large pecan trees, and I’ve replaced all of our turf with mondograss (monkeygrass). I bought the first 2,000 small pots of it, but since that first year I’ve propagated my own transplants. We now have a quarter acre. I like it because I can blow leaves out of it easily (no runners to catch the fallen leaves). As for tilling and adding soil, you don’t want to do that for fear that you would damage the root system.

Dear Neil: My Pride of Mobile azaleas have started to die in spots. Is there a disease I should know about?

There may be, but I can’t tell from this distance. It would be a root or lower stem disease to have killed the plants in this manner. The Texas Plant Clinic at Texas A&M could culture tissues from the living plant immediately adjacent to (below in the photo) the dead area. Sacrifice a bit of that plant’s root system and some of its stems with leaves still intact. Send a copy of this photo in a waterproof zipping bag. Before you do all that, however, check to see if sprinkler heads, if any, might be blocked by the leaf canopy on the lower right end of your photo. To my eye this almost looks more like extreme moisture stress.

Dear Neil: What would be causing parts of my creeping rosemary to look so bad? It looks like it has a gray mold.

That looks like an environmental challenge such as cold damage (if it happened over the winter) or excessively wet soils (if it followed prolonged rains). I don’t believe it’s due to any type of insect or disease. For what it’s worth, my experience has been that trailing rosemary is more likely to suffer cold injury in really bad winters than the tall, upright types. I do note that some of your plants made it through fine. You might have been right on the edge of having no damage at all, or that area might have better drainage.

Dear Neil: What would cause bush lantanas to get rusty looking and have crinkled leaves? Is it a fungus?

Lace bugs. They hit in mid-summer and turn lantana leaves pale beige. Black specks of excrement dot the backs of the leaves. Soon sooty mold grows in the sticky honeydew residue they leave behind. Systemic insecticides control them effectively.

Dear Neil: Our property has loads of bluebonnets, but this is happening to them (see attached photo). I don’t see any insects, and the ground is not wet. Any insights? I don’t think we’re going to have seeds for next year.

All I can see in your photo is dry plants, bluebonnets and otherwise. The soil looks dry as well. Hopefully by the time you see this you will have had rains. If not, better keep the water hose handy.

Dear Neil: I planted Raleigh St. Augustine sod in our backyard due to the shade of a large pecan tree. How fast will it spread? Inches per month/year? Should I fertilize it? I am watering it daily. Any other suggestions?

In good conditions it can grow several feet per growing season. I hope you have that 5 or 6 hours of sunlight daily that I mentioned in the earlier reply. If not, you may see it die away over a period of two or three months. Apply an all-nitrogen lawn food (upwards of half its nitrogen in slow-release form) at half the recommended rate now, then at the full recommended rate in early June. Daily watering is fine for the first couple of weeks, but after that you need to stretch out the intervals and soak the soil to encourage deep rooting.

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.