Fighting the good fight!
These two plants are as frustrating as spring weather in Central Oregon. The good thing is that we have the ability to semi-control annual bluegrass and moss. Tetherow turfgrass has been growing for 5 years and it is maturing rather well. The first hole (#3) was seeded in May 2007 and it has seen a lot of changes both in architecture as well as the maturity of the turfgrass. With age comes a few blemishes and they are beginning to appear this season. What can we do about these two plants? Below is a brief explanation of what we can do to control them.
Annual bluegrass or Poa annua is a species of grass that is usually considered a weed in many cases. Annual bluegrass grows in almost everywhere in the world. The topic of annual bluegrass control can be very intense in the golf world. There are many considerations to annual bluegrass control that can become exhausting when discussed. As for Silvery Thread Moss, it is basically a nuisance and becomes unsightly. Combine the two and the putting surface is adversely affected. Tetherow is seeing some Poa annua establishment and we are slowing down the establishment process utilizing our knowledge and a few products on the market.
Disclaimer: Annual bluegrass is inevitable. Any turfgrass system ultimately becomes dominated by annual bluegrass. Home lawns, sports fields, golf courses, parks all become dominated by annual bluegrass at some point in their life span.
The following is a list of ideas and products that we are using this season to provide the best results against Mother Nature and Poa annua:
- Maintain fertility to a level where the fine fescue and bentgrass are competitive.
- Promote deep rooting of fine fescue and bentgrass through deep and infrequent irrigation and the use of wetting agents. Annual Bluegrass typically has a shallow root system so the developing plant would struggle to obtain adequate moisture.
- Cut out young Annual Bluegrass plants from areas such as putting surfaces.
- Use growth-regulating products such as Cutless and Embark. Cutless selectively suppresses the growth of annual bluegrass to a greater degree than desirable turfgrasses, in our case, the fine fescue and bentgrass mix. Embark is generally used for the seedhead suppression of annual bluegrass. Annual bluegrass can flower and generate new seed at a mowing height of 1/8 of an inch.
- Use a new herbicide, Xonerate, for the control of annual bluegrass. This product is very new to the market and was registered for use in the State of Oregon in April. Trials need to be done to ensure the safety of this product on our fine fescue/bentgrass mix.
- Quicksilver is a herbicide used for the control of Silvery Thread Moss. Last season we used the required amount of Quicksilver spread out over four applications, two in the spring and two in the fall. We observed very good results from the product and will continue this season.
- Iron can be utilized to help control Silvery Thread Moss. Rates as high as 1 pound of Iron product per thousand square feet weaken the moss. Appropriate timing of an iron application just prior to a Quicksilver application will be very effective.
- Most importantly, we will improve the density of our putting surfaces. This helps control both annual bluegrass and silvery thread moss. This season we are overseeding the greens three times with our usual fine fescue and bentgrass mix.
This season will provide the information that is necessary in order to produce a practical plan for annual bluegrass control. Remember that annual bluegrass is considered both a weed and a desired plant. Annual bluegrass is a weed when it begins to encroach on an existing turfgrass stand, such as ours. Annual bluegrass is a desired plant when the natural conversion has occurred and it is now being maintained as a turfgrass stand. The difficulty lies ahead for Tetherow. An example of the conversion from planted turfgrass to one hundred percent annual bluegrass would be:
Tetherow (0% – 1%), Broken Top (50% – 75%) and Bend Country Club (100%)
I hope that everyone has enjoyed the golf course thus far and is looking forward to a great season. I am hoping for great weather in May so that the golf course can really shine for our members and guests. As always, feel free to drop me an email with any questions, concerns or comments at [email protected]
Thank you, Chris Condon, Golf Course Superintendent