Every winter I cringe when I hear people say that they graze grasses down to the ground because the grasses will come back from the roots in the spring. It is true, the grasses probably will come back from the root reserves, but at what price? There are a multitude of reasons not to graze your dormant cool-season grasses to the ground in winter and I’ve listed five of the most compelling below. Even one of them alone could convince me to graze higher, but up against five, I don’t have a snowball’s chance of arguing against it.
I do recognize that others have different priorities, climates and systems. I am sharing with you my experience in Zone 7 trying to bring back overgrazed land with a large emphasis on getting rid of dewormers while keeping the above- and below- ground herds healthy. My primary cool-season grass, fescue, goes semi-dormant during the coldest few months.
1 SPRING BACK IN SPRING!
Cool-season grasses use their leaves as solar panels to actively grow in fall and spring. They have carbohydrate reserves in their stems and lower leaves(+). They also have a backup plan of using root reserves if something traumatic happens, like a fire, but that is a triage measure, and not meant as a prolonged growth method all on its own. Allowing animals to graze to the ground takes away the solar panels and the carbohydrate reserves. If we are proactive and keep our grass longer, we can use the carbohydrate reserves and those solar panels to jump start the growth in the spring. Allowing grasses to have both the solar panels and the carbohydrate reserves will not only make growth skyrocket in the spring when things warm up, it can help in the fall and winter too. Fescue will start to regrow with only 3 days of temperatures above 60 degrees F. That means that if you have warmer winters, or even just a few days of warmer temperatures, you may even be able to grow some forage during the winter.
In addition, the grass crowns that aren’t eaten during a heavy grazing are more vulnerable to hooves if they are uncovered. Damaged crowns may weaken the grass and inhibit growth in the spring.
It is counterproductive to destroy the carbohydrate store and/or root crown so the animals can get one more mouthful so you don’t have to feed hay as soon in the fall. If kept intact, that valuable part of the plant may enable your grass to start growing a week (or more) faster than ‘grazed to the ground’ grass. That is a week or more that you won’t be feeding hay in the spring while your ‘severe’ grazing neighbors are still battling bales.
Grazing expert extraordinaire Jim Gerrish states “The only safe conclusion we can draw is dormant pasture and range should not be grazed “to the ground” even in winter. For tall grass native range, plan to leave a minimum of 4-6 in. residual. For mid or short grass range, leave at least 3-4 in. On mixed cool-season grass-legume pasture, 3-4 in. is good. On tall fescue-dominant pastures, feel free to take it down to 2 in.”
All of these heights are lower than I like to graze mine because of reasons 2, 3, 4 and 5 below.
2 MERRIER MICROBES!
Remember, you are nurturing your micro-herd of beneficial biology below the soil as well as your above-ground herd, and that means 365 days a year. Soil microbes are alive and well in winter(*) and many experts say that is the best time to build soil health. The micro-herd needs food, habitat and water. They can get their food and habitat from the cover you leave for them, and the cover also holds in soil moisture during dry winters. Some people say to graze to 4″, but I disagree. 4″ does not leave enough leaf to lay down and cover the spaces between grass clumps. 6″ is barely enough to be able to do that and frankly I would rather see 9″ on my fields. The best scenario is to have a minimum 1/4″ layer of dead thatch flat on the ground with live leaves over it. This insulates the ground from cold longer, and gives the fungi something to eat. Since most of us are trying to move our soils from a bacterially-dominated to fungally-dominated micro-biome, ignoring the soil cover will never move you in the right direction because you are starving the fungi.
3 SOIL STAYS PUT!
Bare soil is the best way to ensure that you have soil erosion. My goal is to be able to toss a quarter anywhere on my property and have it land on covered soil instead of bare soil. A layer of soil the depth of a dime eroded off of your one acre field is equal to 7 tons of topsoil! Since topsoil is what you are trying to build it is counterprodctive to allow it to float away with stormwater runoff. Keep it covered, all year.
4 PRODUCE A PARASITE PURGATORY!
While parasite eggs may not be able to develop in the winter because it is too cold, some worm larvae can easily survive snow and freezing temperatures to infect your livestock. Many parasites stay in the bottom 4″ of the grass stems, so, as in the summer months, if the animals don’t graze down below that 4″, they have less of a chance of being infected. I can’t definitively say that keeping my forage long in the winter is the only thing that has cut our deworming schedule from 2-3 times a year to zero times in the last 4 years, but I do believe it is part of it. I try my best to graze high all year long.
5 WASTE THOSE WEED SEEDS!
Leaving bare soil allows sunlight to stimulate the weed seeds in the soil seed bank in the spring. The best way to inhibit weeds is to keep your soil covered. Think about what a great job mulch does in keeping most annual weeds from germinating. If you are constantly battling annual weeds in the spring, it may be because you grazed too low in the winter.
The only time I would recommend grazing to the ground would be if I was going to plant annuals the next spring. Since I don’t have any equipment, my best bet to get a good stand is to graze a field severely, broadcast my seed, and then use the animals to stomp the seed into the soil to get good contact. Otherwise, I plan to keep my grass at 6-9″ year round.
If it looks like the animals are grazing too low during the winter, I hold them back on a high area and feed hay, spread out on the ground. I choose higher elevation areas because 1) the soil is usually poorer there and 2) there is less chance of the animals pugging the soil and making a mess on the hilltops since the water runs downhill to pool. I use the animals to sheet-compost the area with hay, urine and manure, and then move them on. Just as I move them daily in the summer, I move them daily in the winter so that parasites don’t become a problem. These areas (usually no more than 10% of my pasture area) do take longer to come back in the spring because they have been grazed hard where the hay is, but they have the added organic matter to improve the forage that year. I have found that it is a worthwhile trade-off.
Some people feel that this hay feeding is a waste of money since I still have grass in some places, but I strongly believe that the return on investment will set me up to feed much less hay in the future. I am feeding my below-ground herd in two places (hay feeding areas and tall grass areas) instead of setting them back by grazing my grass too low and exposing the soil.
Healthy soils to you!