Released Sept. 7, 2007
OLATHE, Kan. - An irony about living in the High Plains (i.e., grass country) is that many homeowners quickly develop a love-hate relationship with their lawn.
"Most want a long season of green. In the central Plains, at least, that fairly well limits them to cool-season tall fescue or Kentucky bluegrass - neither of which is without problems here. What´s `fun´ in Kansas is that the weather´s not only too hot for most cool-season grasses but also too cold for most warm-season turfs," said Rodney St. John, turfgrass horticulturist with Kansas State University Research and Extension.
Plant breeders are always working to develop varieties that overcome some of those problems, St. John added. Thus far, however, even the newest cool-season turfs haven´t tested well in the Heartland.
So, he is advising central U.S. homeowners to be cautious: Wait before adopting any tall fescues touted to self-repair and expand via underground rhizomes (stems). Hold off on buying the "tougher" Kentucky-Texas bluegrass crosses now on sale in some markets.
"These advances in plant breeding sound very attractive. Who wouldn't want a tall fescue that spreads like Kentucky bluegrass? Awesome - right? That´s why rhizomatous tall fescues or RTFs are such a hot topic now," St. John said. "Unfortunately, what we´ve seen so far in K-State´s trials doesn´t indicate the varieties are worth their extra cost."
In fact, at K-State and other central U.S. land-grant universities, the new RTF fescues simply have not produced significant rhizomes or numbers of "daughter" plants. Recently, a non-researcher showed St. John what were supposed to be long, productive RTF rhizomes, but turned out to be underground stems from a Kentucky bluegrass plant.
"It´s still too early in the game to discard the idea of rhizomatous tall fescue. So far, though, it just bears watching," he said.
"Hybrid Kentucky bluegrass," "hybrid blues" and "Texas bluegrass hybrids" are collective names being used to describe some recent crosses between Kentucky bluegrass and a native Texas bluegrass. The first cross to reach the market was developed at Texas A&M University, in hopes the Texas bluegrass would pass along its good heat and drought tolerance and its prolific rhizome production.
"Of course, lots of gene combinations are possible in crossbreeding, which is why human brothers and sisters sometimes don´t look or act as if they´re related," St. John said. "To date, the characteristics of the named hybrid blues have been varying widely. In practical terms, that means the long-term potential for such crosses is still under study and in development."
The hybrid blue varieties tested at K-State evidently did not get their Texas parent´s strong drought tolerance. And, they only beat out standard Kentucky bluegrass on heat tolerance.
"Other researchers have noted that some of the hybrids also have a coarser texture and lighter color than those which make Kentucky bluegrass so desirable," St. John said. "Moreover, the current crosses can grow relatively quickly. That means mowing more often - perhaps as often as you have to mow K-31 tall fescue."
Turf scientists Dale Bremer, Jack Fry and Steve Keeley also are participating in testing the new varieties in Kansas. K-State´s annual "Turfgrass Research" reports for the past 10 years include their results and are on the Web at http://www.ksuturf.com/Researchhttp://www.ksuturf.com/Research%20Repor ts.html.
Further turf-related information and recommendations for homeowners are available at any county or district K-State Research and Extension office. Links to those offices are on the Web at http://www.oznet.ksu.edu under "Need an Expert?" K-State´s Extension turf publications also are on the Web at http://www.ksuturf.com/Homeowners.html.
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http://www.oznet.ksu.edu/news/sty/2007/lawn_turfs090707.htm
Contacts: Rodney St. John, (913) 856-2335, ext. 110, rstjohn@ksu.edu
Kathleen Ward, kward@oznet.ksu.edu
