like it to look more like a golf course grass. I think one of my problems has
be mowing too low, believing it would still green up if I did this. Over the
last two weeks I’ve raised the height of my cut and fertilized. It is looking
much better but probably need another week for it all to get up to the same
height. I’m getting small patches of darker green grass with a wider leaf. I
think this is what they call Poa. Probably
little I can do to stop this Poa weed.
.JPG) |
| Poa annua or Poa as the turfgrass professionals like to call it (or annual bluegrass as some call it) in dormant bermudagrass in December |
A. Depending on the kind of bermudagrass it could be
mowed up to one inch in height. However, most bermudagrasses perform very well
cut at about 1/2 inch in height. Lower than this is for the professionals, in
my opinion, and requires very frequent mowing, a grass catcher and fertilizing
frequently to look good.
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| Mowing should be done so that you remove no more than 1/4 to 1/3 of the leaf blade. If you mow when the grass is too long, like in this picture, you leave behind clumps of grass clippings. I like to call this hay mowing, not cutting the lawn. This also means that when you mow your lawn short it will reach this 1/4 to 1/3 threshold that much faster and you must mow very often. Golf Course Superintendents have some bragging rights when they mow their greens and tees at 3/16ths. Can you imagine mowing to remove only 1/4 to 1/3 of the leaf blade? This means mowing daily or in some cases twice a day! Homeowners should not be mowing less than 1/2 inch on bermudagrass unless you want it to own you! |
you cut the grass, the more often it needs to be mowed. When you have a thatch
problem, mowing low will make it look worse. You really have to address the
thatch problem this fall. If you don’t overseed, the best time to do it would
be in late summer (August) so that the grass has time to mend before winter
sets in. After dethatching, fertilize and water heavily to speed up the repair
process.
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| Thatch comes from dying roots, rhizomes and stolons of bermudagrass. Once it starts to accumulate, then clippings from mowing will also contribute. This must be removed in heavy thatch producers like most bermudagrasses. |
are fewer weed problems when the grass is opened up from dethatching in the
fall than the spring. When you open up a lawn in the spring there are lots of
spring weeds that can invade. Yes, the small dark green patches with seedheads
on many of them now is Poa. Poa is tough to control. The seed is everywhere and
tracks with shoes. If your bermudagrass is an improved type you can green it up
more with nitrogen and iron and this way the Poa is not as noticeable. But it
will always grow a bit faster and is wider bladed than the fine bladed improved
bermudagrasses. Poa is a cool season grass so if you don’t overseed the Bermuda
you could spray it out in December or January with Roundup when the Bermuda is
dormant. The problem will be the Poa seed that is everywhere in your lawn. It
WILL come back.
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| Dethatchers or vertical mowers (the blades spin vertically rather than horizontally as they do in rotary mowers) or even sometimes called verticutters lift the thatch debris from lawns where it can be gathered together for compost. Dethatch in the fall months when weed invasiont after dethatching is less than in the spring months. |
One benefit of overseeding is that it helps to eliminate some of the thatch
because you must dethatch the lawn sufficiently for the seed used in
overseeding can make good contact with the soil for germination.
May years ago
common bermudagrass would be burned in the winter to get rid of the dead
surface grass and in the process any thatch accumulation. It is still
recommended that bermudagrass hayfields be burned for numerous reasons
including thatch removal and reduction of insects and diseases. Years ago
bermudagrass lawns were also burned in the rural areas. We didn’t have a thatch
problem when bermudagrass was burned in the winter. Because we cannot burn dead
grass any more due to local ordinances, this dead grass remains and adds to the
thatch layer.
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| Its a proven fact. Mowing affects the rooting depth of grasses. Close mowing results in shallow rooted lawns. Shallow rooted grasses are more prone to drought problems than lawns mowed higher |
We now substitute a gasoline-driven machine (called a dethatcher,
vertical mower or verticutter) instead of burning the dead grass. This of
course uses petroleum, adds pollutants to the air and leaves this bermudagrass
thatch that we have harvested for dumping somewhere.
A tool I have used in the past is the Red
Dragon propane torch to burn debris. The model with higher BTU’s will burn
grass even if it is wet. This is an advantage because you can wet down the
bermudagrass dead lawn and still burn it which makes it more safe to use. There
are lots of advantages to burning bermudagrass thatch but local ordinances may
prevent you from using it. The burning is done just before spring growth.