I’ve never been a fashion leader or even a follower. I just know what I like and dress accordingly. Carhartt and Wrangler are my “go to” brands for most occasions. The one piece of clothing I have that somewhat keeps me in vogue is the hoodie. The versatile sweatshirt-headwear-storage combo never goes out of style or function and is seemingly appreciated from rodeo to Rodeo Drive.
A good hoodie can save you on those occasional cool summer mornings and nights, but its real utility comes into play as the calendar turns to September, and it remains an indispensable clothing resource through fall, winter, and spring. Let’s also not forget about the hoodie’s large frontal pouch that can hold enough provisions to keep the human body alive for three weeks. It seems that only underwear can match a hoodie’s year-long serviceability.
As we approach the end of August, it’s the hoodie’s time to shine; it’s our time to ensure that our hoodie supply is readily accessible for any task or occasion. The manure-covered barn and cattle-working hoodies must be kept separate from the “going out to dinner” hoodies. All of this is to say that fall and winter are coming, and we’d better be ready.
While we take stock of our hoodie inventories, forage plants will metaphorically be putting their hoodies on, too. Perennial forages have mechanisms for surviving winters, but we need to allow them to get dressed for the colder weather to come. In Northern regions of the U.S., that process starts now.
A critical function
To understand how perennial forage plants prepare for winter, North Dakota State University’s James Rogers points us to the process of photosynthesis in his recent “Forage Matters” column. The forage crops production specialist notes that excess sugars from photosynthesis are stored as carbohydrates in plant organs. These stored carbohydrates are what the plant uses for regrowth and other survival functions.
“For alfalfa, carbohydrate reserves are stored in roots, and in grasses, storage is primarily in the leaf sheaths and stem base,” Rogers notes. “In spring, forage plants use stored carbohydrates to initiate growth until leaves are developed to the point that energy from photosynthesis is fueling plant growth. If the plant is left undisturbed, it will continue to increase stored carbohydrates till it reaches maturity.”
Once plants are cut or grazed, the plant uses its stored carbohydrates for regrowth until there is sufficient leaf area that photosynthesis generates enough sugars to fulfill the plant’s needs for growth. Once again, any surplus carbohydrates are stored for future use.
Initially, the amount of stored carbohydrates used for regrowth is dependent on how much leaf area is left after cutting or grazing and how frequently defoliation occurs. “If the last use of stored carbohydrates for regrowth occurs so late in the season that reserves are not replenished, then we have potentially hurt capacity for spring growth and plant persistence,” Rogers asserts. “But this is a manageable situation.”
Timing is everything
Rogers points to research that has found alfalfa needs 500 growing degree days or about five to six weeks prior to a killing frost for sufficient carbohydrates to build up and be stored in roots. For many Northern states, this means cutting no later than early to mid-September. Of course, for older stands that will be terminated anyway, it doesn’t matter when you cut.
If you’re in a situation where forage is needed, Rogers suggests waiting until temperatures get sufficiently cold that no regrowth will occur. With such late cuttings, leave at least 4 to 6 inches of stubble to help insulate crowns and catch snow.
“Alfalfa can also be grazed late to extend the grazing season — but be cautious — as there is an increased risk of bloat with freeze-damaged alfalfa,” Rogers writes. “Reduce bloat risk by allowing alfalfa time to dry down following a killing freeze prior to grazing.”
Grasses are different
Most perennial grasses are less prone to winterkill and injury from late-season defoliation, but there is an effect. Rogers notes that grasses grazed prior to winter dormancy have a delayed green up in the spring and reduced forage biomass.
“This effect is much easier to manage if you are in some type of rotational grazing system,” the forage specialist points out. “If a paddock or pasture is intensely grazed late in the season prior to frost, then delay grazing this same paddock in the spring until it has adequate time to recover. This might mean delaying grazing that paddock until the plants are approaching maturity.”
Where pastures have been continuously grazed, the delayed spring regrowth is more difficult to manage around because cattle are selective grazers and will tend to eat the same plants repeatedly, if allowed. This puts the most desirable pasture species at a high risk for being terminated.
Fall forage management impacts legume and grass stands in both the short and long terms. Make your cutting and grazing decisions intentionally and provide your fields with the same cold temperature armor and storage capabilities that a hoodie provides you.
