Managing Grazing to Target Cheatgrass and Other Weeds

Thanks for this article go to Ben Beckman, Nebraska Extension Educator, and Mitch Stephenson, UNL Range Management Specialist. They give us an excellent example of what to consider when managing grazing to target cheatgrass. We’ve added some notes on how you can adapt this to other grasses and weeds. Enjoy!

While Mother Nature has been giving us small tastes of spring, then pulling right back, the reminder that pasture green up is just around the corner shouldn’t be ignored. One of the earliest species we see greening up is cheatgrass (also called Downy brome and June Grass, Bromus tectorum). That makes early spring a good time to begin planning for cheatgrass management.

What Do We Know About Our Target?

Winter annuals like cheatgrass germinated and grew last fall. The seedling was dormant all winter but energy reserves from the fall allow for growth right away this spring. This allows cheatgrass to invade into several different plant communities and compete with native cool-season perennials. With warm spring temperatures, plants grow rapidly and mature quickly. Cheatgrass usually reaches reproductive maturity by May or early June.

Cheatgrass grows from 6-24 inches in height and will be a bright green until seeds set. Upon maturity, plants turn red brown in color. Leaves are covered with fine, soft hairs. Each plant produces a distinctive brome seed head that is 2-6 inches in length and droops to one side. The seed head gets a more fluffy appearance as awns dry. Dried seed heads stick to animal hair and fur, or human clothing as a method of seed dispersal. They are also really good at burrowing into socks and shoes. Due to the seed being so easily transported, care should be taken to reduce spread from one location to areas without cheatgrass. This could include moving cattle away from cheatgrass prone pastures before seed maturity to reduce transport.

Cheatgrass can be very invasive, taking advantage of disturbed sites and creating a monoculture where it out competes other plants for nutrients due to its early growth and maturity.  Once mature, the seed head contains awns that can cause irritation for animals grazing or eating cheatgrass contaminated hay.  Dead plants can also create a fire risk, being a fine, dry fuel source just waiting to catch a spark.

While mowing prior to seed set and fall herbicide applications can be effective management practices, there are still many challenges in managing this species. For example, mowing too frequently can harm some of the native cool-season perennials and some herbicides, if timed incorrectly, can affect non-target species.

Cheatgrass as a Forage

Dense patches of cheatgrass can provide high quality forage when it is green and growing, with crude protein percentages of 10 to 15 %.  Best times for grazing are usually from late-April to late-May. However, cheatgrass growth patterns can be highly variable based on temperature and precipitation. Once plants begin to turn from green to purple, the nutritional quality plummets and livestock are unlikely to graze it. With such fast maturity, the window of opportunity from high quality forage to unpalatable forage may only be a few weeks.

Managing Cheatgrass With Grazing

Early-season targeted grazing provides livestock with good quality forage and reduces the number of plants that reach maturity and produce seed. Targeted grazing differs from typical grazing management. It targets a particular species by grazing at a defined season, intensity, and duration to meet a management goal. Early season targeted grazing of cheatgrass patches should be done quickly, a strategy often referred to as flash grazing. Flash grazing allows quick movement, taking advantage of this early flush before it becomes unusable.

When you’re targeting this species, don’t wait for it to get tall. Start when it’s about 2 inches high. Confine animals to cheatgrass patches as much as possible and graze heavily for a short period and then move. Cattle will typically consume native perennial cool-season species along with the cheatgrass. The key is to set back cheatgrass at a critical stage (i.e., right before seed set) and then remove grazing to allow desired species the opportunity to fill in and establish. Critical to the success of targeted grazing is providing adequate time for regrowth of desired species before subjecting them to the stress of regrazing later in the year.

This short video shows results from on ongoing five year research project on cheatgrass targeted grazing. You’ll see what cattle are eating, and the suggested time for targeting the plant. (Video by Julie Kray.)

Planning now on how targeted grazing on cheatgrass may fit into your system is critical to being able to implement it over the next few months.  Knowing where your patches are, developing a grazing plan, and setting up infrastructure (e.g., water and fences) now can help with the success of managing cheatgrass when the timing is right.  Being able to pull the trigger fast can be the difference between successful utilization or missing the window of opportunity.

Now – Let’s Adapt This Concept to Other Potential Targets
Notes from Kathy Voth

Grazing management can be an excellent tool for managing weeds in pasture. It’s good for your pasture, and when grazing weeds you can add as much as 43% in available forage. Following, the example above from Ben and Mitch, let’s look at what we need to do to get started.

1. Know your target.

When does your target germinate? How fast does it grow? When does it set seed? How does its growth cycle compare to the preferred forages in your pasture?

The answers to these questions tell you the best time for focusing on your target. As Ben and Mitch showed us, cheatgrass greens up and starts growing earlier than other cool season forages. That means that we can graze it hard and limit impacts on forages that we prefer.

Does the cheatgrass lifecycle remind you of a plant in your pastures? In my life as a person training cows to eat things they normally don’t, folks have asked me about a variety of grasses that their livestock avoid. Typically this is because they grow quickly in the spring and lose their nutritional value as the grazing season wears on. If that sounds familiar, then consider the targeted grazing guidelines Ben and Mitch provide.

2. Spring Isn’t the Only Time to Target Graze

Depending on your plant, you may target it at a different season. For example, I’ve found it’s best to target spotted knapweed just as it begins to flower. This is typically about July in the arid west, when cool season forages have completed their life cycle and gone dormant. That means you can safely graze spotted knapweed without great impact to your other forages.

3. Make a Plan

How will you get your cattle onto the target weed? Will you need extra fencing and help? Can you coordinate with neighbors to get the most impact?

As with any time you’re grazing, you need to plan how many animals will be where and when. Once they’re grazing, close observation will be important. By paying attention to what animals are doing, you’ll know that if they’re getting as much forage as they need, whether the target plant is being impacted, and whether you need to move to protect your preferred species. There is no recipe for this. But by watching what’s happening you can adjust as you go.