Why is my Bermudagrass Lawn Declining?
It will be a couple of weeks before we’ll know how much, if any, bermudagrass lawns suffered from winter injury this year as the off/on temperatures have things off to a slow start. However, this discussion is focused more on long term trends. In other words, has your bermudagrass lawn declined over the last few years for no apparent reason?
To further fine tune this discussion; let’s assume we are talking about lawns that have been cared for with regular mowing, fertilizer, weed control and irrigation.
If the above conditions are met, bermudagrass should thrive in our area. If it is not looking good and actively growing, there is at least one significant issue holding it back. Based on our client interactions, soil testing, and site visits, here are the most likely causes for decline.
Fortunately, most of these problems can be corrected, once they have been diagnosed. The list begins with the most common:
- Soil pH is either too low or too high. While bermudagrass generally grows well within a wide pH range, it does have limits. It is not uncommon in Payne County to see soil samples come back with the soil pH from 4-5 or near 8, both levels outside the range that allows bermudagrass to flourish.
- Limiting nutrients. Virtually all Payne County soils have enough of the important soil nutrients to promote healthy growth; with the exception of nitrogen, and sometimes phosphorus and potassium. If these are not present in high enough levels, their absence will be the limiting factor for growth. This issue (as well as soil pH) can easily be identified with a routine soil test.
- Irrigation system failure. Make it a point to watch your irrigation system run through its cycles a few times a year to make sure it is functioning as designed.
- Severe compaction. While it might seem like an easy problem to identify, that might not be the case to someone who has recently purchased a property and doesn’t know the history of the site. A good example might be thin areas adjacent to the driveway; it’s very possible the area could be severely compacted from the previous owner parking on the lawn.
- Shade encroachment. Have the trees on your property grown enough that the area in question no longer gets enough sunlight to support bermudagrass growth. The same problem can happen as a new structure (fence, house remodel, etc.) is added to the property. Bermudagrass needs at least 6 hours of full sun a day to be happy.
- Root competition. While this issue usually goes hand in hand with shade competition that is not always the case. Occasionally, something will cause a tree to redirect it’s root growth in one direction, pushing the roots out well beyond the canopy of the tree. Sweetgums, sycamores and silver maples are all trees known to do this.
- Salt damage from ice melt. While this was certainly not an issue this last winter, this can happen from time to time in areas where water collects after running off an area regularly treated with salt to remove ice.
- Improper pesticide application. This is fairly rare but it does happen. Symptoms of this being the problem might include bermudagrass stolons (runners) lying on the ground but not rooting, damaged turf following drainage patterns, or widespread damage to other plants in the area.
Next week we will continue this discussion focusing on solutions to some of these issues.
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 firstname.lastname@example.org, 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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