Mowing Your Pasture . . .or NOT

Poisonous plants, training sheep to eat plants, and helping the grass take over.

I've read about some shepherds who've made a business of taking their sheep and/or goats to various overgrown properties and using these animals to clear out brush and weeds. I thought that was a great idea but after reading about this and then looking over my shoulder at the pasture it bugged me to see that my sheep weren't eating SOME of the plants.

Once again, research was needed on m y part and I soon learned what sheep eat and what they can't eat. I didn't realize that there are some plants that are poisonous.

Many of the articles and blogs I read contained comments where the shepherd appeared to be almost paralyzed finding out the a sheep of their recently died from a plant found in their pasture. Luckily, Blackbelly seems to be a LOT smarter. Blackbelly do a good job at knowing what is good for them and what is not -- Naturally. While they may nibble on poisonous plants, never enough to do harm, they are very selective about their diet and eat what satisfies them nutritionally. While you might have poisonous plants among the good forage, it's really nothing to worry about. 

What does this have to do with mowing?

As I began rotating my sheep through the pastures I saw that some plants were selectively 'remaining'. Keeping up this pattern it became quickly apparent that unless I mowed the sheep were helping the bad players in the field by eating everything BUT them. Given enough time these plants would take over completely with their eating pattern. The plants obviously didn't offer anything to my sheep and the more they spread the less land there would be for grazing. Mowing would be needed.

Even though Blackbelly are good at knowing what's what, in reality there are several reasons for some plants being left behind, 1) They're poisonous, 2) The sheep don't like them, or 3) They don't know to eat them.

Horse Nettle (left) - related to NIGHTSHADE (right)

both poisonous plant in my pasture   

After reading these reason I suppose that the first two make the most sense but the third may just seem a little out of the ordinary if this is the first time you've heard it. But how do sheep learn what to eat? When watching our sheep I'm sure you've noticed they don't exactly have the best communication skills. It seems well beyond the possibility to think that sheep are teaching each other anything at all. But about a year or more ago I heard that cattle can be taught to eat just about anything and I started to wonder if sheep weren't really all that much different; I started looking for clues in their eating habits and soon realized that the sheep actually do learn from one another . . . by watching.

False Dandelion or Catsear - Sheep love it !!

For example, I rotate my sheep through three pastures and found that there are at least two plants that the ewes won't eat but the rams have no problem with. They are the same breed and there is no significant physiological difference between males and females yet the'll eat the plants left by the ewes. Since I have only a few rams and one goat (2 adult rams, 2 young rams, 1 ewe goat) I tend to rotate the rams into the pasture after the ewes have just cleared the pasture and are leaving. The grass and brush may be short but there aren't enough rams to keep the grass short for long and they get a good balance between the brush and the new grass growth.

Trumpet Vine - Sheep hate it, it's a extremely hard to kill, and it roots are deep with shoots. It may be controllable in cold climates but it's exceptionally bad in warm/tropical climates.

While making one of these pasture rotations the weather became a bit too cold and there was less grass than normal. Somewhere along the line they all started eating one of the vines the ewes left behind. Seeing is believing and now knowing that these vines can't be poisonous (my rams didn't get sick) the only conclusion I could draw was that my goat taught the rams or the other way round. Goats tend to forage on similar plants as sheep even though they prefer brush and low hanging tree limbs. I feel that the ewe goat, being more of a nibbler than the sheep, started eating the vines and the rams learned from her. My ewes still won't eat these plants since they've never had the need, desire, or a teacher.

Training a Sheep to Eat Other Plants

I'm certain there are poisonous plants in my pasture and I still haven't taken the time to find out which of these "weeds" are bad and which are safe; be warned before you use this method. While there is a "trick" to teaching foraging animals to eat less-favored plants I personally don't use it because I'm afraid of what plants might be poisonous and their flavor hidden. 

Nevertheless, a simple way to teach sheep to eat a plant is by using a spray bottle filled with a small amount of a diluted molasses solution. Since your sheep are probably familiar with the taste of molasses (if you've used sweet feed in the past) the added carbohydrates of the molasses will make eating these weeds a lot more pleasant and offer a quick energy source. Keep spraying the plants until they are comfortable eating them and then slowly back away from the spray treatment. I'll repeat, I wouldn't suggest this trick until you're certain which plants are poisonous and which are not.

Not being that confident in my plant identification skills it seems reasonable to spray only those things that another ruminant is eating and the rest I mow under before they seed and after rotating flocks to keeping these plants under control and not allowing them to reproduce.

Mowing has differing results on some plants

Grasses will always grow faster than woody or stemmed plants. The more you mow, the more the grass will crowd out other species until you're only left with grass as the other plants are unable to reproduce and die off from disease. If you mow frequently then the predicament you'll be faced with is that you'll be crowding out the wide leafed plants the sheep like in their diet, but if you don't mow then the plants they don't eat will thrive; especially of you rotate your sheep through pastures.

To get around crowding out the "good" weeds while suppressing the inedible plants I try to keep my mowing to a minimum and only in selected areas. I let the sheep eat through a pasture, then, as soon as I rotate them out of the pasture, I kick up the lawnmower and go after ONLY the patches they seem to have avoided. Perhaps if I have enough time I may even spend some time pulling a few of them out by hand to reduce their numbers in time. A few here and there add up in the same way a lot of small projects will eventually build a house.

Looking at the introductory "Pasture Care" page, you'll notice that the first picture shows a large group of red-ish tipped plants which are Trumpet Vine (picture at right). I loved this plant in my garden in N.Y. but it's a complete nuisance in my field here in Texas and grows like gangbusters as it clings to water spouts, fences, trees, other woody plants, barns, . . . you get the picture. What's particularly bad about this plant, pretty as it might become when in bloom, is when left to its own it will grow a thick hard woody stem that the lawn tractor has a hard time with, it is a thick bushy plant that crowds out other grasses the sheep like, and the sheep simply don't eat this plant! For this plant mowing keeps it in check and keeps it from going to seed if I mow at the proper time. But being that it's a deep rooted vine the plant can only be removed by pulling out the entire root system. 

Mowing a patch of the pasture to inhibit unwanted plants & vines

For another plant in the pasture the opposite is true. My pasture has been swampy for so many years that migratory birds have tracked in many varieties of plants. One such plant is grass-like; a type of very thin tubular hairlike grass that spreads among the regular grass the sheep eat. I found that mowing this spiky grass seems to spread it all the more. As opposed to the trumpet vine, mowing this grass would do more harm than good in the pasture because it promotes it's reproduction.

And a third type of plant I find is somewhat neutral to the affects of mowing. I've seen this plant in several states located in the lower lying areas along water and sometimes mixed in with cattails (bull rush) and resembling a small spiky bush of tubular stalks about two feet tall. This plant spreads through it's roots and mowing has no affect one way or the other. The only way to get rid of it is to dig it up.  

Returning nutrients to the soil - Amendments & Clippings

When plants are cut their clippings are returned to the soil as a kind of mulch. As the clippings decay they add to the biology of the soil contributing a significant amount of organics to the topsoil that help it retain water and giving back the minerals and other nutrients to the plants around it. Amusingly enough, this is exactly what your sheep do in contributing manure and urine tp your pasture.

There might be many reasons why a patch of land might not have vegetation growing on it but poor water retention is among the leading reasons. While I'd normally not suggest picking up yard clippings or leaves, there will be parts of your pasture that might benefit from adding organics to the soil. I first learned about soil amendments several years ago when trying to figure out why my grass was dying for no apparent reason in several spots in my home lawn. When I lived in California the type of grass I had required fertilizers but yard clippings caused root rot and hence they were collected. But my yard in the Northeast was suffering because the soil was being leached of all the organics by rain and I was aiding to the problem by not mulching the leaves and lawn clippings.

My discovery hit home after watching a home garden show teaching about the benefits of soil amendments that were lightly added atop the grass in the fall. As I learned, amending your soil by adding yard clippings, top soil, organic fertilizer, or thin amounts of mulch can revitalize the area as the added compost retains water and helps the plant survive long periods of drought. Higher water retention levels will give new seed/plants a better chance at survival and extended growth. The longer a plant survives the more complex its root system will become and that again adds to its chance of survival.

Getting back to yard clippings, if you have the ability to move some of the clippings to the dry or bald areas of your pasture then try applying a light coat (< 1/4") of wet clippings to the area several times during the year or simply add compost to the area and allow it time. Working either of these into the soil will greatly speed the process and adding seed to turned soil may show immediate results.

  Mowing unwanted plants can expose fresh grasses previously hidden