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On September 16, 2012 I concluded a two year trial of five tall fescue cultivars and one Kentucky bluegrass cultivar in my back yard in Buffalo NY to answer the question “Does tall fescue spread?”
The answer is yes and no, depending on how you define the word “spread”.
Tall fescue is known as a non-spreading species; often referred to as a bunch grass. Tall fescue plants produce tillers; leaf blades growing from the basal shoot of the mother plant. One tall fescue plant can produce many tillers. Thus tall fescue turf can grow denser over time but a pure stand of tall fescue is unlikely to spread or fill in dead spots with new plants.
Kentucky bluegrass is a spreading species. The bluegrass plant produces rhizomes, or underground lateral shoots, which extend out from the parent. New plants emerge from below ground at nodes on the rhizome. When these new plants mature they too can send out rhizomes, thus repairing damaged turf with new plants.
In the last decade Barenbrug Seed Company introduced Labarinth, the first spreading tall fescue. Labarinth is marketed as RTF (Rhizomatous Tall Fescue) and was initially sold as a component of Barenbrug USA’s WaterSaver seed mixture. To my knowledge Labarinth was never tested in the National Turfgrass Evaluation Program (NTEP) Tall Fescue trials.
Labarinth RTF led to the introduction of a rash of so-called spreading varieties. The marketing name for the spreading trait varies, but they all imply a tall fescue lawn that will spread and repair itself.
One marketer promoted varieties with SRP, Self Repair Potential. “The presence of rhizomes creates a self-repair potential for this species which can speed establishment, improve traffic tolerance, plus aid and increase recovery potential from damage” they claim.
Another marketer introduced “LS Technology” (Lateral Spread) which “on occasion…have also been observed to create rhizomes, which similar to bluegrass, form distinct new plants adjacent to the mother plant, again increasing stand density and hastening recuperation”.
Another company introduced a RZ version of one of its conventional tall fescue varieties, promising a “rhizomatous or spreading type tall fescue”.
Most impressively, one company touts a tall fescue variety where “nearly 100% of the plants are rhizomatous”. Unfortunately that variety was not in my test.
I’m a bit of a skeptic, especially when it comes to claims of changing the growth habit of a turfgrass species. I’m not saying it can’t or hasn’t been done. I just want to see it with my own eyes before I believe it.
In August 2010 I removed a 8’ by 12’ area of sod from my backyard lawn. I used Round-up to kill anything that grew back, levelled the area with bagged topsoil, and installed black lawn edging to segregate 6 plots from each other and the surrounding lawn.
On September 1, 2010 I planted five improved tall fescue varieties and Midnight Kentucky bluegrass. Three of the tall fescues claim to spread (3rd Millennium, Firecracker LS, and Rhambler) and two make no spreading claims to my knowledge (Faith and Tar Heel II).
I achieved excellent seeding establishment in all 6 plots and fertilized with 1 lb Actual N in fall of 2010.
In April 2011 I killed a circle of turf in the center of each plot by spraying Round-up into a 3 lb coffee can with both ends removed. My intent was to duplicate the turf damage frequently found on home lawns. After about a month I removed all the dead turf down to bare dirt inside the circles.
I fertilized with 1 lb Actual N/1000 three times in 2011 and two times in 2012.
I wanted to test the hypothesis that spreading tall fescues would fill in the coffee can area and the non-spreading varieties wouldn’t. Additionally, I wanted to benchmark tall fescue spreading against Midnight Kentucky bluegrass, a well known spreading variety.
After 2 years I observed the following:
- The Midnight plot completely healed and the killed area was populated with fine bladed bluegrass plants.
- None of the five tall fescue plots showed any evidence of rhizomes. I was able to gently lift up the tillers on the perimeter of the killed area and slide the 3 lb coffee can back in place. In all five plots the bare ground inside the edge of the coffee can was devoid of any grass plants.
- In the five tall fescue plots the plants on the circumference of the circle produced very wide-bladed tillers (4-5 times wider than typical leaf blades in the remainder of the plot). These coarse tillers extended to cover approximately 50% of the killed area.
- There was no obvious difference in the growth habit of any of the five tall fescue varieties.
As I said, the outcome of my non-scientific test hinges on the meaning of the word “spread”.
Turf type tall fescues have always “spread” by producing long, wide bladed tillers on the edge of a damaged area. The varieties I tested did just that. As far as I was able to observe, none of them extended a rhizome (underground lateral shoot) into the killed area during two growing seasons and none of them came close to the self healing properties of Midnight Kentucky bluegrass during that time.
I have read the spreading claims and seen complicated graphs showing how certain tall fescue varieties spread by rhizomes. It seems to me the seed marketers are measuring a distinction without a difference. When you talk to homeowners about spreading grass, they think of Kentucky bluegrass. It is clear from my trial that the term spreading with regard to tall fescue has a completely different meaning than spreading of Kentucky bluegrass.
This trial reinforced the value of tall fescue as a desirable lawn species for northern growing conditions. All five of the tall fescue cultivars had similar color and leaf texture compared to Midnight Kentucky bluegrass. All of them greened-up several weeks earlier than Midnight and stayed green longer under unusually hot summer weather in 2012.
I saw no winter damage in the tall fescues over two winters.
Based on this I will continue to recommend tall fescue as a reasonable alternative to Kentucky bluegrass in the Northeast and upper Mid-West.
If I was a buying tall fescue for my own lawn I would not allow my purchase decision to be influenced by unsubstantiated claims of rhizomes in tall fescue.
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