CO-Horts

CO-Horts

Friday, April 10, 2015

Dog Tuff Grass: A New Turf Species?

Tony Koski, Extension Turf Specialist

African bermudagrass (Cynodon transvaalensis)
Beginning in 2014, I began receiving questions about a “new” turfgrass – being sold under the name Dog Tuff ™ African Dogtooth Grass. The sellers of this grass suggest that its Latin/scientific name is Cynodon hybrida.  I have searched databases for this grass and run it by prominent bermudagrass breeders and researchers – with no one recognizing any turfgrass (or grass, for that matter) with the Latin name C. hybrida.  For you plant nerds out there, you can check the validity of any scientific/Latin name at The Plant List, a working list of all plant species (currently contains over 1 million plant species names). If you want to be uber nerdy, you can even see a photo of the earliest specimen of this grass (housed in the herbarium of the Royal Botanic Gardens, Kew), collected in Africa in 1919. The species was officially named in 1921.

C. transvaalensis is a non-native grass, introduced
from the Transvaal region of South Africa.
Soooooo, this is far from a “new” grass. It is a species of bermudagrass, African bermudagrass (Cynodon transvaalensis Burtt-Davy), used by turfgrass breeders since the 1950s to develop new, interspecific turf-type bermudagrass cultivars. Tifway bermudagrass, released in 1960, has C. transvaalensis as one of its parents. African bermudagrass (AKA couchgrass, African dogstooth grass) is a native of the Transvaal region of South Africa, where it can be found growing on the high grass prairie (veld). This region of South Africa experiences sharp day (70s-80s)/night (30s-50s) temperature differences, and receives 18-24 inches of precipitation annually.


C. transvaalensis can produce a dense turf.
I have been growing this grass at CSU for many years, after finding it in a Denver lawn during the 2002 drought. It forms an attractive, dense sod. The leaves are very fine textured, and the grass spreads aggressively via stolons and rhizomes. It has excellent cold hardiness (one reason it is used as a parent in bermudagrass breeding programs). Left unmowed, it grows to a height of 3-6 inches, depending on how much water and fertilizer it receives. Because of its aggressive, dense growth, few weeds will appear in this turf. However, during the warmest times of the year, mowing will often result in scalping – causing a brownish appearance. Because of this tendency to scalp when mowed, it will probably look more attractive if left unmowed (or if mowed frequently…as in 2-3 times weekly during the summer).

Like all bermudagrasses, C. transvaalensis spreads
by aggressive stolons ('runners')
If this grass is so ideal, why don’t we see named cultivars on the market from breeding programs or sod producers – as is the case with other turf species? It’s because breeders recognize the limitations of C. transvaalensis as a turf grass by itself. It will tolerate very low mowing heights, but the tendency to scalp during the summer (even when mowed daily) is seen a as major impediment to using it as a turf on golf courses or for sports turf.  Its greatest value remains as a germplasm source for the breeding of cold-hardy, fine-textured, high-quality hybrid bermudagrasses. Those considering this grass should also be aware that it is a warm-season grass (like buffalograss), so it will green up sometime in May and become dormant/brown with the first hard frost in the fall.

Bermudagrass is one of few grass species that
spreads by both rhizomes and stolons - a growth habit
that makes it both a traffic-tolerant turf and a potentially
troublesome and difficult-to-control landscape weed
While some may find this grass useful as an aggressive ground cover for certain high traffic areas (dog runs, for example), it is important to recognize the potential for this plant to become a weed in the home landscape. In fact, the reason I found the C. transvaalensis that I currently grow at CSU is because of a homeowner request to ID a weed in their landscape. In recent years, one of the most common weed submissions (samples in the mail, or photos sent by phone or email) I receive throughout the summer is bermudagrass in home landscapes (lawns, shrub and flower beds, vegetable gardens) and on golf courses. In some states (including our neighbor Utah), bermudagrass is listed as an invasive species. In other words, be aware – if you decide to plant this grass – that is has the potential to spread into places where it might be unwanted. And…it can be remarkably difficult to eradicate…requiring multiple applications of glyphosate over an entire growing season.

Bermuda is a warm-season grass, so will have a long
winter dormant period in Colorado
So, yes, it is in many ways a tough grass – because it is bermudagrass. Remember: the perfect turfgrass (for every lawn situation) has not yet been discovered or developed by breeders. Every species has its positive and negative sides – and this one is no exception.

11 comments:

  1. Joe Ferdig, City of ThorntonApril 10, 2015 at 10:49 AM

    Tony, could you say a few words about the true hybrids like 'Riviera', 'Yukon', 'NorthBridge' and 'Latitude 36', especially how they compare to the 100% African Bermudagrass in aggressiveness? I noticed that one sod producer is offering 'NorthBridge' and 'Latitude 36' Bermudagrass; is it safe to assume these are more suitable for landscapes without becoming a nuisance?

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    1. Hi Joe,
      Good question. The short answer is: they are all bermudagrasses, so all of the cultivars have the potential to be weedy. 'Riviera' and 'Yukon' are cold-hardy C. dactylon cultivars that can be seeded. 'Northbridge' and 'Latitude 36' are C. dactylon x C. transvaalensis hybrids - which produce no fertile seed. Thus, they are only propagated vegetatively (sod or sprigs). Both 'Northbridge' and 'Latitude 36' are aggressive growers, making them ideal for sports turf and golf course use - where recovery from traffic and wear is important.

      My point isn't to necessarily discourage the planting of bermudagrass. It's important for people to understand what they are planting, the potential for weedy behavior, and to plant it in the right place/situation. Bluegrass can be weedy too - growing into flowerbeds and vegetable gardens.

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  2. Great post, Tony. I so appreciate the clarification regarding this grass. We get so many questions about the "best grass" at the Colorado Springs Utilities Xeriscape Demonstration Garden. It's great to have the best information available to complement the marketing info out there.

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    1. Thanks Catherine! I've been getting so many questions about this grass. No grass is perfect for every situation...as you know. But that's the question we always get.

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  3. Tony, I think you are confusing Dog Tuff with the species Cynodon transvaalensis. Dog Tuff is a hybrid form of Cynodon and most likely a cross between C. dactylon x C. transvaalensis and produces no fertile seed. This is very important and prevents this selection from being invasive like weedy seed grown varieties. While it is an aggressive spreader in the landscape, it is very sensitive to glyphosate. Using a lawn edger to separate the runners from the main lawn (to prevent translocation of the herbicide), the runners can be sprayed with glysophate and will die quickly. This grass will likely become a very popular lawn grass in CO because of its very xeric nature, its cold tolerance, esistance to weeds and its ability to withstand intensive foot (paw) traffic.

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  4. Thanks for all your efforts that you have put in this .very interesting information.i would like to do all the information

    artificial grass suppliers in delhi

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  5. Can you add a Cynodon hybrid to your existing lawn ? and if I would to start a new lawn which would be the best if you have dogs
    Thanks
    Karl

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  6. We haven't done anything to our 'yard' but there is no grass. We bought this place almost a year and half ago and it had been vacant for a few years before that (repo) so no one did any maintenance. The previous owner landscaped it with small rock. But being neglected for a few years allowed foxtails and other weeds to work their way up through the rock. We live in the high desert so grass is not really practical here, but this rock is rather boring. I would like to scrape it all up and start over with a more natural desert look. Just haven't had the energy to begin such a large project. Guess we will have to put it on our list pre-spring next year.
    Artificial Lawn

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  7. Once your land is all set, you can drop the seeds. If it is small area the seeds can be sown with hand. Else, you can use lawn spreader or a mechanical seeder for larger areas. But make sure that you do not sow mo0re than 16 seeds per square inch. After the seeds have been planted cover them with a layer of soil and fertilizers and water them regularly. grass seed suppliers

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