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While the first frost of the year isn’t here yet, how we manage pastures in the fall 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 stressed by high temperatures and drought, 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 grazed this fall 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 unwanted plants and open the door for warm season grasses.
And speaking of unwanted plants, fall is an ideal time to control perennial and winter annual or biennial species in pastures. Biennial thistles like musk, plumless, scotch, and bull growing now are new plants that started from seed this year, forming a new rosette. When trying to control biennial thistles, spraying the new growth of the rosette means better control than after plants have bolted next spring. This is true for all winter annual species like downy brome, pennycress, mustard, marestail, sheperdspurse, and prickly lettuce.
Perennial weeds can be better controlled by fall applications too. While spring applications are our best option for control, fall spraying can 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 weed patches over time. The best candidates are perennials that have new growth which can better absorb chemical, like leafy spurge and Canada thistle. Be sure to spray before leaves change to fall colors, as the amount of herbicide that will be translocated to the roots will be lessened after this occurs.
Fall usually is focused on harvest and it may be easy to push pasture considerations to the side, but a little effort now could mean a big impact on pasture 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. Right now is also time to plan for control of perennial and biennial weeds like thistles. Actual spraying should wait till closer to a killing frost. Control measures this fall can make a big impact on numbers next spring.
