Clover Control

Clover Control

White clover tends to create fewer problems in horses and can be used sparingly in seed mixes but should not make up more than 1% of any horse pasture mix.

Photo: iStock

Q. I enjoyed your recent blog post about pasture weed management. I, however, struggle with clover in my fields. It grows so low that I’m unable to mow it, and now it’s spreading and outcompeting the grass. Do you have any management suggestions to control clover that don’t involve herbicides?

Laura, via email

A. Laura, there are several reasons why an excessive amount of clover may be growing well in your fields—most of them come back to management techniques. Good for you for looking at the root of the cause instead of wanting to go to the quick fix: chemicals. We do need to be careful about the chemical choices we make in our daily lives as those impacts all add up.

The clovers themselves are not known to be toxic to horses; it is thought that the problems associated are a result of the different types of molds that grow on clovers. Clovers are not typically a problem in dry hay, although a high percentage of clover in hay can prolong drying time and increase the chances of moldy hay. Some horses do not find dried clover palatable.

Clinical signs of clover ingestion by horses vary (according to the type of clover ingested and how much mold) but include different degrees of photosensitivity on the white parts of the horse’s skin, yellowing of the membranes around the mouth and eyes, slobbering, even colic if the amount of clover (and mold) is very high.

A little clover can still be useful in horse pastures. Clovers are legumes and legumes “fix” nitrogen, adding it back into the soil. White clover tends to create fewer problems in horses and can be used sparingly in seed mixes but should not make up more than 1% of any horse pasture mix.

Clover generally takes over when the conditions for growing grass are not optimal. If grasses are growing well they get tall, thereby shading and outcompeting the clover. Here are some reasons why your grasses may not be as productive and some ways to manage that:

  1. Overgrazing. Horses tend to select for grasses instead of clovers. This means that over time grasses are eliminated, leaving only the clovers.
    Solution: Cross fence pastures and implement a rotational grazing system. Never graze below three to four inches. This leaves grasses with at least three inches of leafy material for rapid regrowth.
  2. Poor soil fertility. Clover tends to grow in nitrogen deficient soils. If the soils are low in nitrogen, the grass plants can’t grow tall and outcompete the clover.
    Solution: Have a soil test done for your pastures and apply amendments (such as lime, fertilizer, or compost) accordingly. Soil testing is relatively inexpensive, usually $15 to $35 per test. Contact your local conservation district, extension office, or Natural Resources Conservation Service (NRCS) to get a list of soil testing labs and information on how to take a soil sample. Applying any amendments without a soil test is purely a shot in the dark, potentially a waste of money, and definitely an environmental hazard (because of runoff of unused materials.)
  3. Compaction. Clovers are tolerant of poorly drained soils and, along with weeds, tend to grow in compacted soils that make water infiltration and grass root growth difficult.
    Solution: In the winter keep horses off saturated and rain soaked soils and dormant or frozen pasture plants. Soggy soils and dormant plants simply cannot survive continuous grazing and trampling in winter months.

By utilizing these simple pasture management techniques you will be creating healthier, more productive grass plants, which means less clover. Healthy pastures also have the added benefit of making happier, healthier horses; a prettier picture for you and your neighbors; and a cleaner environment for all!

About the Author

Alayne Blickle

Alayne Renée Blickle, a lifelong equestrian and reining competitor, is the creator/director of Horses for Clean Water, an award-winning, nationally acclaimed environmental education program for horse owners. Well known for her enthusiastic, down-to-earth approaches, Alayne is an educator and photojournalist who has worked with horse and livestock owners since 1990 teaching manure composting, pasture management, mud and dust control, water conservation, chemical use reduction, firewise controls and wildlife enhancement. She teaches and travels North America and writes for horse publications. Alayne and her husband raise and train their reining horses at their eco-sensitive guest ranch, Sweet Pepper Ranch, in sunny Nampa, Idaho. She also authors the Smart Horse Keeping blog.

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