Grazing Bites: Time To Frost Seed Clover?

By Victor Shelton,

NRCS State Agronomist/Grazing Specialist

I know that there are a lot of people who really enjoy winter. I’m not one of them. The only good things about winter is I don’t have to mow the yard and I might find more time to catch up on my reading. The best part of winter is when it’s over!

Winter does tend to be one of the better times for me to do some maintenance. I spend time fixing or building fences, as long as the ground isn’t frozen too much, recycling old metal, removing brush, and frost-seeding clover. Just like fences need some periodic maintenance to keep them in good shape, keeping a sufficient amount of clover present in the pastures also takes a little attention.

Most of our white clovers do a fairly good job of sticking around from year to year. Typically they are white Dutch type clovers, a Ladino, or more likely a cross between the two. They are heavy nitrogen producers and add a lot of value to a pasture, boosting yield and feed quality. Some of the newer varieties of white clovers are a lot more aggressive than the older Dutch clovers. They are typically Ladino crosses and do a better job of getting leaves up higher in the canopy and competing with the grasses present.

This competition can be a problem. If it is a newly planted pasture, the more aggressive Ladino type clovers can start growing in the early spring before the grass takes off and become quite competitive for the existing grasses. This tends to be more of a problem if the clover and the grass are planted at the same time. It generally is better to plant the grasses first, such as in the fall, and then come back and over-seed or frost-seed the clovers on during the winter dormant months. That gives the grass a bit more of advantage that first spring. If planted at the same time, and especially if too much clover is planted, then stands in the spring can sometimes be sixty percent or better. Clover, especially white clover, that dense can cause bloat issues.

In pastures where the grasses are already established, the opposite is quite often true. The grasses can be too much competition for the clover to get established. This is one case where some pre-dormant, tighter grazing can help. By grazing the grass closer and not maintaining the normal prescribed stop grazing heights of three or four inches for cool season forages, you can delay the growth of the grass for the spring, which will help establish the frost-seeded clovers.

Red clover can also be a good legume for pasture. Red clovers are not as long living as white clovers and usually tend to thrive for two to three years. If you are going to be cutting the field for hay, red clover is a better choice over white clover. It yields better and certainly dries better than white clovers. It tends to have a fairly shallow root system, especially in wet years. If cutting for hay in a wet year, it’s best to cut a little bit higher than normal, at least three inches. I have seen almost ninety percent stand loss from cutting short and then the weather turning dry. There is some research that indicates that isoflavones in red clover may help reduce tall fescue toxicosis. It’s been preached for a long time that while diluting the alkaloids in tall fescue with clover and other species certainly helps, red clover may go beyond just diluting and may actually offset potential damage from the fescue alkaloids and also help ruminants digest protein more efficiently.

The negative aspect of red clover, or more precisely the isoflavones produced by it, is it can interfere with the estrous cycle in sheep and reduce lambing rates. This can be avoided by not grazing areas with high amounts of red clover at least 30 days prior to breeding.

Right now is a good time to be thinking about adding clover to your pastures or hay fields. Frost seeding is certainly one of the least expensive ways to enhance the stand of legumes in your pastures. It is basically the process of broadcasting the legume seed onto the soil surface during the winter dormant months. For the most part, I usually say the ideal time period is somewhere between Christmas and Valentine’s Day.

You already know that I’m not a fan of winter and could really pass on the snow completely except maybe for only about a week right before Christmas, but it does come in handy for frost-seeding clover. A light snow on the ground serves for a couple good purposes. First, it helps “catch” the seed and transport it to the ground. Second, it serves as a great marker for the tractor or ATV. A good heavy frost can also work. It just happens that I’m getting some snow as I write this today and have some clover that needs to be sown. Guess I know what I’ll be doing soon.

I usually recommend slightly higher seeding rates for frost seeding than for conventional seeding. White clovers can be seeded at 1-1.5 lb. per acre, remembering that it is a much smaller seed than red clover and will be around longer. You can get it on too thick and yes, I know, it’s hard to seed that small amount! I’ve found cat litter is not too bad of a carrier if needed; just make sure to mix it all well to distribute the seed evenly or have your seed dealer mix it for you, then allow for that carrier to get the correct seeding rate. Red clover should be seeded at 6-8 lbs. per acre. All legumes should be inoculated with the appropriate inoculants for that species to insure proper bacteria, good germination, and growth. That inoculant also helps to maximize nitrogen fixation, and you certainly want to take advantage of that! Most legumes have a specific Rhizobia (soil bacteria that fix nitrogen) so select the ones for the species being planted. Quite often, the inoculant is included on coated seed, which is also easier to plant.

Keep warm and keep on grazing!

Source: osu.edu