Beware the attack of the winter lawn weeds


While winter-dormant St. Augustine lawns have yellowed, something is going on under the soil.

Winter weeds are beginning to germinate. And a lot of weeds do well here. Plantain weed, nutsedge, henbit, spurge, purslane, chickweed, and thistle are a few of the unwanted guests that plague our lawns in late winter and early spring.

Don’t despair. St. Augustine is the best weed-suppressing grass there is, followed only by Zoysia. Both are aggressive plants and, if properly maintained, will keep the weeds to a minimum, if not entirely eliminate them.

Weeds do like compacted, poorly-drained soil, bereft of available minerals, nutrients and organisms.

Residents who apply organic matter to lawns in mid-fall and mid-spring have already established a strong defense against weeds. And although these are ideal times to spread organic matter, anytime is okay.  Aerating the lawn before adding organic matter is another step in the weed war. The organic matter helps soil to drain, and simultaneously holds enough water to establish a strong root system, and is the first and most important step in having a beautiful lawn.

Winter weeds start poking their heads up when the first string of warm days come in January or February. The best method to get rid of them is to simply pull them up and dispose of them in your green waste. Mowing them down before they seed also gets rid of them, but a grass catcher is necessary to keep the weeds from falling back onto the ground.

But weeds are ornery and persistent. Even in the most well-cared-for lawn, it’s probable that a few plantains and thistles are going to pop up. While “manufactured” herbicides may not be the best choice, there are a few products available to the environmentally conscious homeowner.

Agricultural vinegar is available at many garden stores. It is tried and tested and will destroy even the most persistent weeds. It even works on that super weed – nutsedge. Just be careful. Agricultural vinegar is much stronger than the normal white vinegar that most people keep in their kitchens. Wear gloves (preferably rubber gloves) when applying.

One application of agricultural vinegar eliminated a sizeable stand of nutsedge growing in the Alden Bridge Community Garden recently.  Ammoniated soap of fatty acid or potassium soap of fatty acid are also effective herbicidal treatments for weeds, though more effective on plantain, wood sorrel, and spurge.

Whether using vinegar or soap of fatty acid, it’s not necessary to spray a whole area. Simply spot spray each weed.  A spray bottle works well.

While corn gluten has been touted as a great pre-emergent herbicide, but there seems to be some disagreement as to its ability to suppress weeds. It’s also extremely expensive.

Whatever method residents use, creating a healthy lawn is an ongoing process, not an isolated event.

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10 reasons not to plant a winter lawn


As St. Augustine grass goes dormant in the fall, many homeowners over seed their lawns with winter rye. While winter rye does add a lush greenness to an otherwise dull lawn, homeowners may want to rethink this habit.

  1. Save water. Winer rye needs watering three times a day for the seed to germinate. Once established, ryegrass needs watering every three to four days. Dormant St. Augustine needs little or no water.
  2. Save money. In much of the area, annual sewer rates are determined by the amount of water used during the winter months of December, January and February. This is typically when the least amount of water is used. The watering requirements for winter rye increases the amount of water used dung that period, thus raising sewer bills for the rest of the year. Additional costs include mowing, labor and cost of seed.
  3. Prevent fungal diseases. Although damage from take-all patch and brown patch becomes evident in late spring and summer, these diseases actually attack St. Augustine in the winter. Other fungal diseases like rust and powdery mildew are common in winter rye. Winter rye seed may be infected with one or more of these fungal diseases. Irrigation during the winter actually encourages these to infect and damage the lawn.
  4. Save on fertilizers. Augustine does not require fertilization in the winter. Winter rye usually does.
  5. Prevent pests from infecting St. Augustine. Rye grass attracts army worms, wireworms and aphids, all of which can wreak havoc with St. Augustine. Many of these insects can overwinter in the topsoil and return in spring to re-infest the lawn.
  6. No need to scalp lawns. Planting winter rye usually means scalping the lawn first. The problem here is that St. Augustine should NEVER be scalped. St. Augustine spreads by above-ground stolons. Scalping severely damages the plant.
  7. Decrease noise pollution. While some enjoy the droning of mowers and blowers, these noises may not be the most welcome sound while sitting in the backyard on a mild winter day.
  8. Preserve the quality of water. We don’t live in a vacuum. Foregoing the planting of winter rye means less fertilizers, pesticides, herbicides and fungicides will be used. A significant portion of water pollution of our streams and waterways comes from runoff of these products.
  9. Give your St. Augustine a break! over seeding with winter rye can be very stressful for St. Augustine. Scalping the lawn to plant ryegrass stresses it. In spring, rye competes with St. Augustine for water and nutrients, further weakening it.
  10. Save time and frustration. Seed germination problems, diseases, irrigation, fertilizing, noise, stress to the grass and to the homeowner, are additional reasons to forego winter rye.