During the past week, I attended two classes in the City of Santa Monica’s Sustainable Landscape for Professionals Program, taught by Russell Ackerman, Water Resources Specialist. Tuesday’s topic was “Lawn Alternatives.” It was more about alternative types of lawns (e.g., UC Verde™ Buffalo Grass) than about alternatives to lawns (e.g., a native garden or an edibles garden.) Still, it was very useful information. In designing gardens, I must listen to clients’ wishes, and be ready to present lots of options.
Below is a photo I took of a new UC Verde™ lawn in Santa Monica featured on a Lawn Alternatives Tour. We met the homeowner and passionate member of the (commercially sponsored) GrassRoots Program, Tom Engelman, who designed, installed, and mows the lawn himself. He experimented with turf colorant by Becker Underwood (Ref: here) and one called Kameelyan Bermuda by D. Ervasti (Ref: here), and only mowed one side of the lawn. Of course, it would not have browned that early, but Tom admitted to being a bit heavy-handed with fertilizer, which left a few burned areas he then treated with colorant. It is irrigated using a subsurface grid of Netafim Techline CV™ dripperline, available through local irrigation supply houses. (Ref: here) To keep stolons from invading nearby beds, Tom surrounded the lawn with a swath of river rock between concentric rings of synthetic bender board. The lawn was planted in spring 2009 and photographed in September 2009. I must admit my bare toes were quite happy walking around on this fine-textured lawn. And, I suffered no ill effects, owing to it being a virtually pollen-free, sterile, female hybrid. Allergy index scale rating is “1” (lowest) on OPALS. (Ref: Allergy-Free Gardening, Thomas Leo Ogren, 2000, Ten Speed Press.)
Tuesday’s class featured a presentation by Tom Hawkins, President of Florasource, Ltd. plant brokerage, which markets UC Verde™ Buffalo Grass (variant of Buchloe dactyloides.) While the species is not native, and has performed poorly here, this particular variant was developed specifically for our milder, coastal and inland lower elevation climate zones by University of California, Davis, and introduced in 2004. (Above 2,000 foot elevation the variant ‘Prestige®’ is recommended. And, in colder climates, ‘Legacy®.’ Both were developed by University of Nebraska.) Supposedly, once established, the lawn uses less than 40% of the amount of water used by a Bermuda lawn, and compares even more favorably to tall fescue lawns, such as Marathon. So far, it presents naturally disease and pest resistant in the landscape. Recommended mowing height is 2 to 3 inches. Tom indicated 3/4 to 1 inch height is tolerated, but appearance suffers. Of course, it can be left un-mown for a meadow look, and it will attain a height of approximately 6 to 8 inches. It thrives in hot sun, but does not perform well in shade. Minimum half-day sun is recommended.
It has a softer, finer texture and color than more typical turf grasses. Believe it is better suited in a drought-tolerant landscape than as a foil for rich green, hardy shrubs of a traditional landscape. It goes semi-dormant in California, becoming “straw green.”
Downsides discussed: Being sterile, UC Verde™ does not seed, and given its structure, sod is not practical. It is established via plugs, a rather labor-intensive process. Having less volume and weight, however, plugs maybe more economical in terms of transportation/resource cost. While it will stand up to casual play, it doesn’t tolerate heavy trampling such as on a sports field. Tom said it is as susceptible to salt damage as a conventional lawn, so pet urine can be problematic. However, if left un-mown, the spots do not show as much. It is a running grass, which stolonizes, spreading above ground. This helps it knit together over damage spots. However, it does not spread rhizomatically and it has no seedheads. It is, therefore, not expected to be widely invasive. While it appears to aggressively resist weed infestation, it can be overtaken by Bermuda. Tom was quite candid about this, suggesting if one has a well-established Bermuda lawn, which is less thirsty than tall fescue, it might be more sustainable to leave it in place than to resort to heavy use of chemical means to eradicate the Bermuda. Without fully eradicating Bermuda, planting UC Verde™ may be a wasted effort.
A warm-season grass, UC Verde™ is best established during extended heat – mid-April through summer. To establish, especially in hot, inland areas, Tom suggested placing the crown of plugs slightly below grade and applying a generous layer of fine organic mulch (e.g., seed topper.) Soil around plugs needs to be kept moist. If too dry, runners will arch in the air and will not take root. Also, tips will turn brown. (Spray) irrigation recommended is 3 to 5 minutes daily to establish. Tom recommends using Zeba cornstarch-based polymer (according to product directions) for water retention in areas with 2-day per week watering restriction. (Ref: here) In Los Angeles, for example, with drip irrigation this may be unnecessary under current phase of Water Conservation Ordinance as drip is exempt from the day of week restriction. Once the plugs have spread into the native soil (3 to 4 weeks), the plugs should be “mowed” to encourage faster, denser spread. Once established, one may choose to leave it un-mown. However, Tom recommends mowing once per year in November, just as it goes semi-dormant. The period of semi-dormacy is generally early November through mid-February. Although he does not recommend, Tom has seen it successfully planted as late as November. Plugs lay dormant under over-seeded topper. When this is done, Tom’s recommended species for over-seeding is the native annual Vulpia microstachys. This information may be moot in view of our water situation. Over-seeding would likely require winter irrigation, a waste of water, in my opinion.
Additional note regarding irrigation: If you have a Weather Based Irrigation Controller, you may need to use an override feature to properly irrigate this plant material. It is not yet listed on WUCOLS (Water Use Classification of Landscape Species), but this should be rectified with the next edition of WUCOLS.
During class, I asked Tom Hawkins about establishing and maintaining UC Verde™ organically. He said, “yes.” However, I believe it would take longer to establish, requiring a longer period of intensive irrigation, and more diligence in the weed control department.
Recommendation: Generally, I do not favor turf-type monoculture. However, if intent on having a lawn, UC Verde™ is worth considering, subject to confirmation of economic and other benefits/concerns in your real world setting. If a designer, when specifying, consider including the words “NO KNOWN EQUAL” to avoid contractor substituting inferior/wrong variant or the species.
Tom showed a photo of plugs being installed directly through killed “cool season” (fescue-type) lawn left in place as a cover. This certainly saves having sod hauled away. It would not be effective with a rhizomatic lawn like Bermuda, or even a more shallowly rooted running grass like St. Augustine.
More information about UC Verde™ may be found on the following sites:
While I am lawn-less and loving it, I guess if you have to have a lawn...
Thursday’s class was half in Spanish (which I understand little of), but fortunately, there was a companion slide presentation and quite a bit of discussion in English. The topic was “Sustainable Garden Maintenance.” It focused on maintaining a native and drought tolerant garden, emphasizing the need to move away from reliance on fuel consuming power tools. There was some lively discussion from a diverse audience of gardeners, landscape maintenance crew, contractors and even a couple of designers. Key take-aways:
• Pajote! = Mulch!
• Don’t turn soil! = No voltiar la tierra
• Pull weeds = Sacar la raiz [root(s)] manual [or, manualidad? = manually]
All of the Santa Monica classes emphasize water and other resource conservation in the landscape. To achieve this we should include plants naturally from similar “Mediterranean type” climate zones (see relatively small dark areas on map below.) And, we should minimize or eliminate use of plants from other parts of the world with moist summer weather (e.g. tropical, temperate and colder zones.)
Above slides used by permission of City of Santa Monica, Office of Sustainability and the Environment.
5 days ago