Replacing Lawns with Wildflowers Part 2

Home Grown  by Keith Reed
Last week we talked about the biggest challenge to seeding wildflowers into an existing home lawn; eliminating bermudagrass from the area. Before we move on to other aspects of a successful wildflower establishment, here are some follow-up considerations for this difficult task.

For gardeners committed to non-chemical control options, the choices are nill. All you can do is watch the garden carefully and dig out new bermudagrass plants as soon as you see new leaves pop up. When a new leaf breaks the soil surface, it’s almost certain to be attached to an underground rhizome. It does little good to simply remove new leaves as they appear unless you are prepared to do it repeatedly for months while waiting for the rhizome to deplete its energy reserves. Make sure to remove all the rhizomes you find.

Stay on top of this process by checking the garden at least once a week otherwise you’ll risk losing too many small wildflower seedlings from competition and soil disturbance.

For those comfortable using herbicides, here are some general guidelines to keep in mind. First, there are no effective organic herbicides for this task. While there are some products on the market than do offer effective weed control, they are not effective on bermuda because they do not translocate down into the rhizome. They work only on the leaf, making them no more effective than pulling the leaf as mentioned above. This also holds true for the home brews and other weed killing remedies that you’ll find on-line.

Glyphosate, (the active ingredient in Roundup but also found in dozens of other products), while not 100% effective in killing bermuda, is the best herbicide on the market for the job. This product is non-selective, meaning it will kill or severely damage all green plants. If it is to be used in a new wildflower planting, extreme caution must be used in the application where the threat of overspray can be completely eliminated. Experience has shown that attempting to use glyphosate for this application lends itself to less than satisfactory results for this reason. If a careless application equally damages new seedlings and the adjacent bermuda, any guesses which one recovers the best?

A better herbicide option is to choose one with selective actively on grasses only. Look for products containing the active ingredient sethoxydin or fluazifop. These are commonly sold using names like Over the Top or Grass Getter. While these products tend to work slowly, they do translocate down into the rhizome. Even this option is may need repeat applications for maximum effectiveness.

By this point in this conversation, it should come as no surprise that these products also have significant limitations to their effectiveness. While reading/understanding and following the instructions on a pesticide label is always of utmost importance, it is even more so with this class of products as the difference between successful control and failure can be very small.

Note: Bermudagrass eradication is a particularly difficult gardening task. Based on my decades of experience, I would venture to say that 8 out of 10 attempts end in failure with the gardener giving up or starting over. Persistence is the key!

For more information on this or any other horticultural topic, you can contact Keith Reed, the Horticulturist in the Payne County Extension office. Keith can be reached via email at keith.reed@okstate.edu, phone at 405-747-8320, or in person at the Payne County Extension office, located at 315 W. 6th in Stillwater.

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