Horse Pasture: Which Grasses Are Best for Your Horse?

October 7, 2025

Understanding horses’ digestive needs

Horses possess a unique digestive system that thrives on a continuous supply of nutrient-dense, high-fibre forage. This forage is digested through fermentation in the hindgut, providing essential nutrients and energy.

The type of grass your horse eats can have a significant impact on their digestive health, nutritional balance and general wellbeing. Different grasses contain varying levels of fibre, sugars, protein, minerals and naturally occurring compounds, some of which can cause problems for susceptible horses.

Understanding what is growing in your horse's paddock is an important part of managing their diet.

Impact of grass moisture content

The moisture content of grass significantly affects fibre intake. Green grass typically contains more water and less fibre by weight than dry, mature grass. Horses grazing on lush grass day and night without adequate fibre can develop imbalances in their gut microbiome.

A horse's hindgut acts as a fermentation vat, breaking down fibre and producing fatty acids that provide energy. Maintaining a consistent supply of suitable forage supports this natural digestive process.

Ideal grass for horses

Mature, dry grass provides valuable fibre for horses. However, many horses graze on short, green, fertilised or unsuitable grass species that have been selected for livestock such as cattle and sheep. These pastures can encourage rapid weight gain and may supply excessive sugars, protein or other nutrients for some horses.

Horses generally benefit from a forage-based diet that provides plenty of fibre without excessive energy or unsuitable mineral levels.

Even grasses generally considered suitable can vary considerably in their nutritional composition. Growth stage, weather conditions, soil fertility, rainfall, drought, frost and fertilisation all influence what a horse consumes.

Risks of unsuitable grass

Some grass species can contain high levels of sugars, fructans, protein, nitrogen, potassium, oxalates, mycotoxins or other naturally occurring compounds. These can affect susceptible horses in different ways, from influencing mineral absorption to contributing to digestive, metabolic, skin or behavioural problems.

Even a suitable grass species can become problematic under certain conditions, including spring or autumn growth, after frost, following fertilisation, after drought-breaking rain or when pasture becomes overgrazed.

If your horse isn't grazing mature, dry pasture, provide suitable grass hay to maintain adequate fibre intake.

Identify your pasture grass

Knowing which grasses and plants grow in your horse's paddock helps you make better feeding and management decisions. The following guide outlines common pasture grasses, their potential concerns and the species to watch for.

Generally suitable grasses for horses

The following grasses can provide useful forage when they're suited to your climate and managed appropriately. Their nutritional composition will still depend on growing conditions and maturity.

**Rhodes Grass**: Subtropical to tropical & dry climates.

**Creeping Blue Grass:** Temperate climates with moderate rainfall.

**Kangaroo Grass:** Warm, dry climate. Drought tolerant.

**Wallaby Grass:** Temperate climate to subtropical regions.

**Red Grass:** (Bothriochloa macra) Warm, dry climate.

**Weeping Grass (Microleana):** Warm, humid environments.

**Spear Grass:** Warm temperate climates. Drought tolerant.

**Timothy Grass:** Cool temperate climates.

**Yorkshire Fog Grass:** Cool, moist temperate regions.

**Queensland Blue Grass:** Warm, humid, subtropical climate.

**Brown Top:** Cool, moist temperate climates.

**Pangola / Digitaria Grass:** Warm
climates. Drought tolerant.

Problem Species

**Rye grass:** High in potassium and sugars; risk of metabolic disorders & ryegrass staggers.
Endophyte fungi living inside the grass can produce mycotoxins

**Clover:** Contains phytoestrogens that may disrupt hormone balance. High in starch & sugar. Phytodynamic pigments which can lead to skin issues & can aggravate head flicking.

**Tall Fescue:** Some strains may contain toxic endophytes. Associated with reproductive problems for pregnant mares. Also risks for laminitis horses.

**Kikuyu Grass:** High in sugars; risk of metabolic disorders and oxalate.

**Couch Grass:** Difficult to control; prone to overgrazing & oxalates.

**Sweet Vernal Grass:** Contains coumarin, which is toxic if it gets mould.

**Paspalum:** High sugar content and can get ergots on seedheads during humid weather. Also risk of paspalum staggers.

**Phalaris:** Can cause neurological problems such as phalaris staggers.

**Cat's Ear:** Potentially harmful toxins which can lead to stringhalt. Often confused with dandelion!

Oxalate grasses

Some pasture grasses contain oxalates, which can interfere with calcium availability. Long-term grazing on high-oxalate grasses can contribute to calcium deficiency and associated problems.

Read our guide to Oxalate Grasses and Calcium Deficiency in Horses to learn which grasses contain oxalates and how to support your horse.

**Green Panic:** Megathyrsus maximus subsp. pubiglumis: May also contain steroidal saponins.

**Pangola / Digitaria Grass:** Warm, humid climates. Drought tolerant.

**Guinea Grass:** Megathyrsus maximus subsp. maximus

When horses graze predominantly on oxalate-containing grasses, their overall diet and calcium intake need careful consideration.

Not all calcium supplements are equal. A suitable chelated mineral blend such as Xtracal can help provide nutritional support when managing horses grazing oxalate-containing pasture.

For more information, read our guide to oxalate grass and how to manage it.

Other compounds in pasture that may affect horses

Oxalates aren't the only naturally occurring compounds worth considering when assessing your horse's pasture. Potassium, fungal toxins and plant pigments can also influence the suitability of certain grasses and plants.

Mycotoxins

Some pasture grasses, including ryegrass, tall fescue, paspalum, phalaris, couch, clover and kikuyu, can harbour fungi associated with mycotoxin production.

Read our guide to Mycotoxins in Horses to learn more about where mycotoxins come from, the signs to watch for and how to support your horse.

Fluorescing pigments and photosensitivity

Some pasture plants contain compounds that can contribute to photosensitivity in susceptible horses. Clover, St John's wort, buttercup and plantain are among the plants to be aware of.

Affected horses can develop redness, soreness, inflammation or skin damage, particularly on areas exposed to sunlight. These changes can sometimes be mistaken for ordinary skin irritation or mud-related skin problems.

Toxic Trees and Plants

It's important to keep your horse's pasture free of harmful plants, particularly when grazing options are limited. Hungry horses may consume plants they would otherwise avoid.

Read more about Plants that are toxic to horses.

Know what is growing in your horse's paddock

Pasture is much more than simply grass. Different species can provide very different levels of fibre, sugars, protein, minerals and other naturally occurring compounds.

Knowing what grows in your paddock helps you make better feeding and management decisions.

When assessing your pasture, consider: