Monday, July 30, 2012

Brace Yourself for a Bermudagrass Invasion

By STEVE BOEHME

Does your lawn have unsightly brown patches all winter? Are your flower beds being taken over by a creeping grass that you can’t seem to get rid of?

Lately we’ve seen many landscapes where Bermudagrass has taken over lawns and then invaded the flower and shrub beds. The grass creeps along the ground, rooting wherever it touches the soil or mulch, forming a dense mat. It has a deep root system that can grow more than four feet deep. We’ve seen it come up right through asphalt paving.

Needless to say, a weed this aggressive can ruin your landscaping in short order when it moves from the lawn into gardens and tree wells. Few herbicides are effective against it. Before mechanized farm machinery, Bermudagrass was the weed dreaded most by farmers.  Considered an invasive species in 48 states, it crowds out most other grasses and smothers gardens. This invasive nature leads some gardeners to give it the name of "devil grass."

Controlling it is a real challenge. Here are some quotes we found in online forums about controlling Bermudagrass:

“Get rid of Bermuda...that is SO funny!”

“About 12 inches of concrete will stop most (but not all) Bermudagrass (some will still grow in the cracks).”

“People tell me the only way you can get rid of it is to move.”

So why would all these people be obsessed with getting rid of Bermudagrass? We found many websites online promoting and selling it, both as lawn grass and pasture forage for livestock. It is more popular in the Sunbelt states where it stays green all year, but many homeowners in Ohio have Bermudagrass lawns. You can spot it at a distance in the fall after the first frost because it turns an ugly brown in an otherwise still green lawn. Bermudagrass hates cold weather and survives Ohio winters by extending its roots below the frost line. Last winter’s mild weather didn’t set it back very much.

If you try to control Bermudagrass by tilling or cultivating, the weed will spread because cultivation chops the stems into segments and each segment becomes a new plant. Stripping the top few inches of sod off doesn’t work at all. Spraying with non-selective weed killers like Remuda or Roundup will kill the rest of your lawn, but will not kill Bermudagrass seeds in the soil. You’ll have to re-treat the area for years to kill new Bermudagrass seedlings.

The only practical solution we’ve found is a selective Bermudagrass killer for lawns, based on fenoxaprop-p-ethyl. This chemical is available in a ready-to-use, hose-end sprayer; it’s a concentrate that mixes with water as you spray. We carry it in our garden center.

In order for Bermudagrass control to work, it must be applied during summer. It’s most effective if done in July with a follow-up in August. It’s easy to use and kills not only Bermudagrass but crabgrass, foxtail, sandbur and some other grassy weeds. It will not kill lawn grasses, and, with a few exceptions, won’t harm other types of plants in your landscape. It takes about an hour after spraying to become rainproof.

If you want to stop a Bermudagrass invasion, you need to get started with a spray program right away. Once the weather starts to cool, the grass will go dormant and spraying won’t be effective. Because there will still be Bermudagrass seed in your soil and beds, you’ll have to be vigilant next year or it will get re-established.

You’ll want to re-seed your lawn with good grass seed; fall is the best time to do this. We recommend turf-type tall fescue blends for most lawns. This can be applied a day or two after spraying Bermudagrass killer and won’t be affected. Killing invasive weeds is the first step, but in order to have a weed-free lawn you have to focus on growing vigorous lawn grass.

For a complete program to establish healthy turf, see “Lawn Restoration 101 on the “Weekly Blog” page of our website.

Steve Boehme is the owner of GoodSeed Farm Country Garden Center & Nursery, located on Old State Route 32 three miles west of Peebles. You can read previous columns on the “Weekly Blog” page at  www.goodseedfarm.com or call (937) 587-7021 for gardening assistance.

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