Saltgrass could be new turf variety
Native grass tolerates drought, salt, traffic
By Susan McGinley
Vivid green lawns can exact a high price in Arizona: they tend to guzzle a lot of expensive water because of our desert climate and harsh soil. Although Bermuda grass may handle the heat, it still needs regular irrigations and doesnt tolerate excessively high salt conditions.
Looking for an alternative, University of Arizona researchers in the College
of Agriculture and Life Sciences began collecting native saltgrass plants
from open areas in Colorado in 1995, and have been testing them for
possible turf cultivation in Arizona.
We got interested in this grass because it grows in areas that
only get periodic water, says David Kopec, a professor in the
UA Department of Plant Sciences. It grows in dry, salty soils
and tolerates salty water. We grow it at the college farm with well
water and it does fine.
Both are very salt-tolerant, Kopec says. They have
deep underground rhizomes, deeper than Bermuda. They are found where
there is runoff water, in saline soils. They are often the only grass
growing there. Like Bermuda, inland saltgrass is a warm-season
grass that goes dormant in the winter, but its slower growing
than Bermuda, and could be more invasive. It doesnt need mechanical
aeration because it lacks the stolons that make thatch. Instead, multiple
stems shoot straight out of the ground.
Kopec collected more than 200 individual inland saltgrass specimens
in Colorado in 1995, and brought them back to the UA Karsten Turfgrass
Center (see sidebar), where he conducted greenhouse trials on them in
1996 and 1997. He mowed the individual plants three times per week to
find out which could tolerate mowing and would thus be suitable for
lawns. He and his team then selected the best types and planted them
outdoors in replicated plots in 1998.
After treating them just like turf for three years, the researchers
identified seven or eight plants out of the original collection that
would fit the bill as true lawn types, according to Kopec. These plants
had a good, green color, high shoot density, were softer to the touch,
and covered the soil completely under mowing stress. Each was an individual
Between 1998 and 2001, Kopec noted that these plants survived for four
to six weeks each summer without any irrigation at all, although some
did lose color. It would be a big improvement to have a grass
that needs very little watering, he says. A standard lawn
of Bermuda grass needs more frequent irrigation than the Distichlis,
and the water quality has to be better. Other grasses would struggle
on the amount and type of water that saltgrass survives on.
Kopec plans to patent the better plant types through the UA and thus
is looking at ways to protect the germplasm. The cultivars dont
have names yet, just experimental designations. He is cooperating on
this project with researchers from Colorado State University, who are
studying ways to propagate these plants from both seed and sod. In about
five years he hopes a public variety will be available.
While collecting other specimens to test, Kopec found new saltgrass
types growing undetected on golf greens, tees and fairways. And
in Fredonia, Arizona, I found a plant growing in a restaurant parking
lot where trucks were driving over it, Kopec says. I took
it back to the greenhouse and grew it out. It was so vigorous it practically
turned into a pine tree.
In his field trials Kopec is running more tests to find out how to manage saltgrass as a lawn, including its tolerance to increased mowing and different mowing heights, to increased traffic stress, and to pesticides (although it doesnt appear to be susceptible to many insect pests). The toughest specimens will be planted later in really bad spots to see how well they do. One thing hes already figured out, though, is how to handle the weeds. Thats easy, he says. We just throw salt on the plots.