With their bright array of yellows, pinks and purples, the thistles rapidly propagating in Marin County are lovely to look at. But to ranchers in need of healthy grasslands for their cattle, they are a menace.
The county is teaming up with the Marin Agricultural Land Trust to help Chileno Valley ranchers get rid of thistles and other weeds that are invading the region’s ranchlands. Cattle won’t consume the spiny intruders, which are far more drought-resistant than the grasses cows and sheep like to eat.
A new three-year pilot program aims to encourage ranchers to adopt non-chemical means of weed control, and to work together to tackle a problem that has reduced grazing land and contributed to the growth of fire fuels.
The pilot program will cover 50 percent of the costs incurred to implement sustainable measures to improve soil quality, with a $10,000 annual limit.
“This program is meant to help ranchers regain lost land so that it can be used for grazing,” said Stefan Parnay, Marin County’s agricultural commissioner. “Right now, those areas don’t get used much at all during the year.”
Marin is contributing $265,000 to the project, and MALT is chipping in $100,000. Tristan Brenner, a program manager at MALT, said invasive weeds are a problem that impacts everyone, not just ranchers. “Not only are working lands becoming unusable, but invasive weeds are outcompeting native plants and even increasing the risk of catastrophic fire in our community,” he said.
Chileno Valley was chosen for the pilot because of its extensive thistle invasion and its contained geography that will make it easier to track progress. If the pilot succeeds, Commissioner Parnay said, he hopes the Board of Supervisors will expand it to agricultural lands across the county.
Ranchers who currently use low-toxicity herbicides to manage the most difficult thistle infestations can participate in the pilot, he said, but the program discourages the practice. “One of the keys to this program is improving soil health,” Commisioner Parnay said. “There’s a lot we can do to make soil healthy.”
Ranchers have a variety of tools to promote soil health, including spreading compost, using soil amendments to limit acidity, reducing the number of animals that graze in a pasture and employing rotational grazing. If a herd grazes for too long in the same spot, the grass gets too low and weeds move into bare spots.
“If you have healthy soil, you are going to have a greater amount of forage, and your forage is going to last longer in the season, all the way into the early summer,” Commissioner Parnay said. “The root systems on the forage are going to be deeper and stronger and more drought-resilient.”
Ranchers know they must be good stewards of the land, he said, and the program will help them take the steps needed to protect it. “It’s just general ranch maintenance,” he said. “The land is what feeds them, and if they can’t successfully use the land, they’re going to have trouble staying in business and being viable.”
Sally Gale’s family has been ranching in Chileno Valley since 1862. She and her husband, Mike, graze beef cattle and sheep and grow apple and pear trees on 586 acres of farmland. They’ve been engaged in a years-long battle with distaff thistle, one of about several thistle varieties in Marin.
“That’s the weed that’s the biggest deal for us,” she said. “In this valley, it has spread really like wildfire. It spreads from one ranch to another, and it spreads over borders. If you don’t do anything to it, it just covers your whole ranch. It’s a very invasive and difficult plant to
eradicate.”
The Gales tried everything they could think of, from mowing and controlled burns to inviting a cellist friend to play while volunteers hand-picked the thistle. Finally, they resorted to an herbicide that has limited the spread of the weed, although it is still not contained.
“I prefer not to use any sprays at all,” Ms. Gale said. “I don’t use anything on my vegetables or flowers or trees. But this invasive thistle is so bad, we feel we have no choice. We use it sparingly.”
The new cost-sharing program has been enthusiastically received by all the ranchers Ms. Gale knows in Chileno Valley. “It enables a larger group of people to get on top of a problem that’s valley-wide,” she said.
Program funds can be used to purchase equipment such as seed spreaders, aerators and mowing equipment, and to cover the cost of soil testing and soil amendments. “It’s really expensive to manage these invasive weeds,” Commissioner Parnay said. “It takes a lot of energy and effort.”
Fifteen ranchers have signed up so far, and they can receive guidance from the University of California Cooperative Extension and the Natural Resources Conservation Service if needed.
“We recommend that landowners work together to purchase and share equipment to make their dollars go further,” Commissioner Parnay said. “Weeds know no boundaries. If one neighbor is working very hard at this, and the next neighbor does not, that’s a huge problem.”