Ventenata

Ventenata (Ventenata dubia) is a non-native annual grass native to Eastern Europe. It has been well established in the Great Basin for many years and has become increasingly common in Montana in recent years. It was added to Montana’s Invasive Species List in 2019.  It is a “winter annual”, which means the plant only lives one year, sprouting its initial growth in late fall thru early spring and maturing in mid-summer.  It is extremely aggressive and can out compete all of our native grasses - even the non-native scourge cheat grass. It grows to a height of 6-18” and forms dense monoculutures. Because of its very high silica content, grazing animals will not eat it, selecting instead the more palatable nearby plants and giving ventenata an even better potential to invade. Ventenata, possibly more than any other invasive found on the RMF has the potential to radically change the unique grassland ecology that makes the RMF a productive and diverse place. Given the movement of forage such as hay (particularly in drought conditions) across state lines, the potential for invasion on the RMF is high.

So far ventenata has only been reported at two sites on the RMF – in the rights of way of Highway 287 and Highway 200, both in Lewis and Clark County. The Montana Dept of Transportation has been successfully treating these areas.  In terms of detection, ventenata is fairly easy to overlook. From a distance it looks somewhat like cheat grass, but does have a tell-tale “look” once a person sees it and makes a positive ID.  It matures in July, which, along with cheat grass makes it stand out as one of the earliest maturing grasses and aids in detection. It is becoming wide-spread and locally common in Western and SW Montana.                                               

To this end, the RMFWR will be embarking on systematic ventenata surveys of public roads leading west into the RMF from Highway 89, 287 and 434. We will “Divide and Conquer” by splitting the RMF into sections that will be traveled in mid-July each year on a rotational basis.  Any suspect patches will be inspected closely for positive ID and any ventenata infestations will be reported and aggressively treated by the proper County Weed Districts. In this way we hope to stay on top what will surely be an inevitable invasion. As always, Prevention is the cheapest and easiest form of weed management. While ventenata is relatively easy to control with herbicide, the cost of effective herbicide is high. Our aim is to stop the problem before it explodes into something extremely costly to manage.                                             

  Photo courtesy Jane Mangold

For more in-depth information on ventenata, check out the references below:

https://apps.msuextension.org/montguide/guide.html?sku=MT201810AG

https://agr.mt.gov/Topics/N-P/Noxious-Weeds-Pages/Task-Force-Pages/Ventenata

If you believe you have found an infestation of ventenata, please mark the location in someway that makes it easy to find again and contact the Rocky Mountain Front Weed Roundtable and/or your County Weed District. Thru education and working together we can all help keep the Rocky Mountain Front a unique and productive landscape for all of its inhabitants.