While truly cold weather may still be a few weeks away, how we manage fall pastures can impact plant health through the winter and ultimately production next spring. Are you giving your pastures proper care this fall?
As temperatures cool, plants that overwinter are working on building up reserves before they become dormant. Cool season species like brome, wheatgrass, bluegrass and fescue will often produce a flush of fall growth if moisture is available. Since this flush stays in a vegetative state, quality can be high.
For plants that have been stressed by high temperatures and drought this summer, grazing now can actually deplete energy reserves going into the winter. This may result in decreased productivity and increased weed pressure next spring. Stockpiling this growth for use after the plant is dormant this winter may be a better option. This maximizes productivity this fall while still maintaining forage quality, albeit a bit lower than if grazed fresh.
For many of our native warm season species, their annual growth is wrapping up. While grazing these plants now won’t have as big of impact as actively growing cool season species, they too can be stressed by overgrazing in the fall. Pastures that are grazed in the fall this year should be given a break next year during critical growing periods in early summer if possible to rejuvenate plant vigor.
In mixed pasture where cool season species are invasive, there may be opportunity to control or reduce these gasses with grazing. Animals grazing these pastures will graze the new growth harder, with limited utilization of more mature warm season species. Keep a close eye on grazing progress and pull animals once the cool season species have been used and they begin selecting warm season grasses. Follow this with more targeted cool season grazing next spring to weaken the unwanted plants and open the door for warm season grasses to fill in.
And speaking of unwanted plants, October and early November is an ideal time to control thistles in pastures. Most of our thistle species in the state fall into two categories, biennials or those that grow over two seasons and perennials, those that come back year after year. Biennial thistles like musk, plumless, scotch, and bull growing now are new plants that grew from seed this year and are forming a flat rosette. When trying to control biennial thistles, destruction of rosettes prior to flowering (bolting) is an effective means of preventing seed formation and subsequent spread.
Another thistle to look out for is Canada thistle. Canada thistle is a creeping perennial that can be controlled with fall spraying, in conjunction with other management options in the spring. Fall herbicide applications on perennial species deplete energy reserves and stress the plant as we head into winter. This weakening when maintained for several years, paired with spring control to prevent seed production can slowly shrink even hard to control Canada thistle patches over time. Just like their biennial cousins, this time of year, Canada thistles will also be primarily in a low growing vegetative form.
While in the rosette stage, thistles are more effectively controlled using herbicides. It is important to note that fall spraying of thistles is not a silver bullet and effective control often needs repeated applications. It will take several years of timely control before the soil seed bank is reduced to the point that new plants stop sprouting.
When it comes to treatment options, there are many herbicides labeled for thistle control. Take care when selecting a product that grazing or harvest restrictions meet your operational plans and that you are picking the correct product. Some products traditionally recommended for spraying thistles have recently changed product names, so keep an eye on the active ingredients to make sure a change in name doesn’t also mean a change in action.
Some options to consider are GrazonNext® HL, Milestone®, Chaparral®, Graslan® L, Stinger®, Overdrive®, and Tordon 22K® are all products that are labelled for use on biennial thistles as well as Canada thistle. 2,4-D mixed with dicamba is also an effective option but should be sprayed when temperatures are warmer for the highest efficacy. Tordon 22K® or Graslan® L, are both restricted use products containing picloram. Use extreme caution around other vegetation, especially trees, as both products will kill woody plants.
With harvest in its early stages, it may be easy to push pasture considerations to the side, but a little effort now could mean a big impact on productivity next spring. Manage late season grazing to give pastures time to recover before dormancy, or use selective grazing to knock back invasive cool season species. While we’re at it, right now is also the ideal time to spray troublesome perennial and biennial weeds like our invasive thistles. Control measures this fall can make a big impact on numbers next spring.
-Ben Beckman is a beef systems Extension Educator serving the counties of Antelope, Cedar, Knox, Madison and Pierce. He is based out of the Cedar County Extension office in Hartington. You can reach him by phone: (402) 254-6821 or email: ben.beckman@unl.edu