JANUARY 11, 2012
Jerry Sieve Spring 2012 classes @ Paradise Valley Community College
Go to My.maricopa.edu to register.
PVCC @ Black Mountain Campus is located near 60th St. and Carefree Highway.
Intro / Intermed Digital Photography (Tues/Thurs); Jan. 17 – May 11, 9-11:45 a.m.,
(3 credits, Art 142/143)
Non Credit Continuing Education:
Basic Photography for Everyone, Feb. 1-15, 7-9 p.m., 3 Wednesdays
Basic Landscape Photography, Feb 22 – April 4, 7-9 p.m., Wednesdays+field trip
Philosophy of Photographic Art, March 22 – 29, 7-9 p.m., Thursdays
BY THOM HULEN | JANUARY 11, 2012
A beautiful, but invasive grass, not to be befriended
Fountain Grass (Pennisetum setaceum) is a handsome perennial bunch grass (2 to 3 feet tall) that can be found in landscapes throughout the Phoenix metropolitan area, including the communities of Cave Creek, Carefree, Scottsdale and the unincorporated areas toward I-17. Planted for its attractiveness and hardiness, it can escape into wild undeveloped areas and exclude native plants including grass species through competition for space, nutrients and water. Fountain grass can grow in dense clumps whereas most native grasses do not.
Native to Africa, fountain grass is a less desirable food for native herbivores (plant eaters) than are the native grasses that have evolved in the Sonoran Desert along with the herbivores. Such life includes microorganisms, insects, rodents, rabbits, javelina, deer and big horn sheep. As one walks through one of the area’s many desert arroyos, it is not uncommon to see native bunch grass like deer grass munched to the ground while the adjacent exotic fountain grass remains uneaten.
Fountain grass growing in dense clumps can be a serious wildfire hazard. Adapted to respond favorably to wildfire in contrast to native Sonoran Desert plants that are poorly adapted to wildfire, fountain grass fires are hot and spread fast causing more damage to the native landscape and to private property. Fountain grass sprouts quickly after a wildfire thus giving it an added competitive advantage over native species.
Another advantage that fountain grass has is that with people planting and irrigating this plant in their yards, there is an ever-growing supply of seed being produced that can spread to wild areas. During dry periods when unirrigated native grasses may fail to set seed, nearby irrigated fountain grass continues to grow and set seed that can take over areas formerly occupied by native species. This species can set seed several times per year.
The Desert Foothills Land Trust responds to this problem on its preserves by removing by hand most specimens encountered. Removing specimens with ripe seed heads requires some finesse to make sure that seed is not scattered in the process. It is necessary to place a bag over the seed heads before pulling or cutting the plant down. It is better to pull the plant out roots and all, because the plant can re-sprout from its roots. When this is not possible, it is necessary to repeat the process several times until all the energy stored in the roots is consumed. Removing the stems and leaves prevents that plant from conducting photosynthesis or making its own food.
Homeowners and landscapers have other options available to them. Planting noninvasive native bunch grasses (Muhlenbergia capillaris, M. rigens, and M. emersleyi) is one option, especially if people want to attract native wildlife to their yards. People who insist on fountain grass can use a variety of fountain grass (Pennisetum setaceum ‘Rubrum’) that is reported to be sterile (does not produce viable seed). This variety has a purplish color and is readily available at most nurseries.
Exotic invasive species are a serious threat to natural ecosystems everywhere. To preserve natural species diversity we must be careful and vigilant with species we introduce to new areas. Remember, there are always unintended consequences for our actions.
For more information check out the following websites: Crimson Fountaingrass at Invasive Plant Atlas or Southeastern Arizona Wildflowers.
Or the book Plant Invaders: The Threat to Natural Ecosystems. Chapman & Hall: London. World Wide Fund for Nature written by Q.C.B. Cronk and J. Fuller, 1995 (available from Amazon).