PREVENTING WEEDS

                If you remember, last fall I was discussing how ideal the autumn situation was for wildflowers. The drought had resulted in reduced plant cover on roadsides, vacant lots and pastures. The wildflower seeds that were laying dormant on the soil did not have any competition for a place in the sun. When the rains started wildflower germination and potential was exceptional. The rains, however, did not stop and the winter was ideal for bedstraw, henbit, thistles, and other cool weather broadleaf weeds. They have been on a growing binge. Everything is green and lush. Unfortunately, the bluebonnets and many other desirable blooming weeds are being overwhelmed. The expectation now is that we may have a mediocre wildflower year.

            For controlling the bountiful weed crop in our lawns there are several tactics that can be followed. I like the strategy where the lawn is mowed on a regular basis, usually once per week, to prevent the production of seed heads. The warm weather will start soon and the cool weather weeds will decline quickly. It will be unfortunate in some cases because the annual bluegrass, rye, and rescue grass has produced a very nice lawn.

            For those of you who prefer a more active tactic against the weeds, Weed-Be-Gone, Wipe-Out and similar products will kill broadleaf weeds like henbit, clover and bedstraw. They are contact herbicides that kill existing weeds. Read the label closely to insure that they are applied in a manner that does not kill trees or flowers.

            One product type that I DO NOT recommend is “Weed and Feed”. The timing is all wrong. We may need the herbicide now but it is too early to fertilize the lawn. The fertilizer is utilized by actively growing cool weather weeds, the same ones we are trying to kill. Buy herbicide and fertilizer separately. Fertilize your lawn with slow release lawn fertilizer in April or May.

            For readers that have trouble with summer weeds like sandburs or crabgrass, it is time to apply a pre-emergent granular herbicide. A pre-emergent herbicide such as Amaze, XL, Balan, Betasan, Portrait, etc. prevents weed seeds from germinating. Applied now to lawns it will prevent summer weeds from growing. Again, read the label carefully. Do not apply a pre-emergent herbicide to areas where you want wildflowers or grass seed to grow. The herbicides do not know the difference between desirable seeds or undesirable seeds and prevent both from growing.

            Like lawn fertilizer, we have a tendency to apply lawn seed early. Bermuda and buffalo grass can be grown from seed in full sun situations but not in March. The soil is still too cool for effective germination. Wait until late April or even May for fast coverage.

            There is a lot to do in the landscape now, but resist the temptation to plant grass seed, fertilize the lawn, or use “weed and feed”. Wait until late April on the grass seed and fertilizer, and never use the “weed and feed”, it is not effective in San Antonio.