How Many Acres Does a Horse Need? Pasture, Dry Lots and Rotational Grazing

The short answer

Most US extension services give a rule of thumb like this:

• 2 acres of well-managed pasture for the first horse,
• plus 1 acre for each additional horse.

That much good grass can supply most of a horse's forage in the growing season, with some hay to fill in. Poor soil, dry climates and short seasons call for more land. In arid parts of the West, a horse may need 10 acres or more of native range to find enough to eat.

Horses are hard on pasture. They graze some areas down to the dirt, leave other spots where they've dropped manure to grow tall, and their hooves tear up wet ground. Five horses on five acres with no management will usually end up with a field of weeds and bare patches within a couple of years.

What a pasture is for

Before you count acres, decide which of these describes your plan:

1. Pasture as feed. The grass provides most of the horse's diet from spring through fall. You need enough land, good soil and active management.
2. Pasture as partial feed. Grass provides some forage, and you feed hay for the rest. This is the most common setup on small farms.
3. Turnout for exercise. The horse lives on hay, and the paddock is for movement and social time. Any safe, well-fenced space works, though larger is better for the horse's mind and body.

All three are fine for a horse. Trouble comes when owners plan for the third and expect the first.

Why grass height matters

Grass stores energy in the lower few inches of the plant. When horses graze it shorter than about 3 inches, the plant has to use its reserves to regrow and gets weaker each time. Grazed too short too often, it dies, and weeds take over the bare ground.

The simple rule:

• Start grazing a pasture when the grass reaches about 6 to 8 inches.
• Move horses off when it's grazed down to about 3 to 4 inches.
• Rest it until it grows back to 6 to 8 inches. In spring that might take two to three weeks; in midsummer, longer.

Rotational grazing

Rotational grazing divides pasture into smaller sections and moves horses between them, so each section gets a rest. It's the most effective way to get more grass from less land.

A simple setup:

1. Divide the pasture into three or four sections with temporary electric fencing. Polywire or electric tape on step-in posts is cheap and easy to move. See our picks for electric fences for horses.
2. Graze one section until it's down to 3 to 4 inches.
3. Move the horses to the next section, and mow the one they left to even out the tall clumps. Drag it with a harrow to break up manure piles in hot, dry weather, which helps kill parasite eggs.
4. Come back to the first section once it has regrown.

Water access in each section, or a central lane back to a waterer, makes rotation much easier.

The dry lot, or sacrifice area

A dry lot is a small, fenced area where horses stay when the pasture needs a break: during wet weather, in early spring, in drought, and in winter. Feed hay there. It's called a sacrifice area because you give up the grass in that spot to protect the rest.

• Size: at least a few hundred square feet per horse, more if horses don't get along. Bigger is better for movement.
• Location: high, well-drained ground near the barn and water, away from streams and wells.
• Footing: gravel or stone dust over a geotextile fabric holds up far better than dirt, which turns to mud.
• Shelter and water: a run-in shed and a reliable waterer.

A dry lot also helps manage easy keepers and horses at risk of laminitis, because you control how much grass they eat. See our guide to laminitis.

Fencing basics

• Height: perimeter fences for horses are usually 54 to 60 inches tall. Taller for stallions and jumpers.
• Visibility: horses run into what they can't see. Board, rail, vinyl and wide electric tape are all visible. Plain wire alone is not.
• Safe materials: board, vinyl rail, high-tensile wire with electric, and woven "no-climb" wire mesh are common. Avoid barbed wire, which causes terrible injuries to horses.
• Electric fence: an electric strand on top of a board or mesh fence keeps horses from leaning on and chewing it. Choose a fence charger sized for your fence length, and check it with a fence tester.
• Gates: at least 12 feet wide for equipment, with latches a horse can't flip open.

Walk the fence lines regularly. A sagging wire or broken board is an injury waiting to happen.

Shelter, water and safety

• Shelter: horses need a place out of wind, rain and sun. A three-sided run-in shed facing away from the prevailing wind works well. Allow roughly 100 to 150 square feet per horse.
• Water: each horse drinks 5 to 15 gallons a day. A tank or automatic waterer in each pasture or at a shared spot is essential.
• Toxic plants: walk your land and learn what grows there. Red maple leaves (especially wilted), black walnut, yew, oleander and several common weeds are dangerous to horses. Your local extension office can identify plants.
• Hazards: remove old wire, machinery, holes and trash from pastures.

Pasture maintenance through the year

• Soil test every few years and lime or fertilize based on the results. A soil test kit gives a starting point; your extension lab gives a full report.
• Mow after grazing to keep weeds from going to seed and to encourage even regrowth.
• Overseed thin areas in early fall or early spring with a horse-safe pasture mix.
• Control weeds by mowing, spot spraying and, most of all, not overgrazing.
• Keep horses off wet pastures. Hooves on soggy ground destroy grass roots and create mud.

Sources

• University of Minnesota Extension: Managing Established Horse Pastures
• University of Minnesota Extension: Pasture Site Planning
• Michigan State University Extension: Rotational Grazing for Michigan Horses
• Penn State Extension: Mud-Free Turnouts for Horses