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Resowing Pasture

Great horse track system in the UK

The grass in this particular district of the UK is so unsuitable for grazing horses all year round that this wonderful Track Livery was set up - such an asset!: Gawsworth Track Livery


We are seeing more and more reports of people purchasing ‘Horse friendly’ seed mixes only to find that the mix is totally unsuitable due to it being some guy at the seed merchants’ idea that low endophyte rye and white clover (or red) are fine for horses.

The picture of the paddock that is a ‘sea of white clover’ is what sprouted when a paddock was sown with a ‘horse-friendly’ mix. This wouldn’t be safe for any livestock let alone horses!

CLOVER is unsuitable forage for horses and although rye-grass is OK in SMALL quantities, the fact it is low-endophyte or endophyte free (which produce myco-toxins) does not render it suitable for horses.. Endophytes which produce mycotoxins are only one of the many reasons rye-grass/clover pastures play havoc with the horse’s metabolism.

Mineral imbalances, sugar content, fructans, photodynamic pigments which cause mud-fever & sunburn are all problematic in rye-grasses. Italian rye-grass for example, a zero endophyte’ strain turns out to be far from ideal.

We helped a lady several years ago who had resown all her horse paddocks with Italian Rye Grass thinking she was doing the right thing, and all seven of the horses grazing it came down with serious staggers as soon as spring hit. The ‘staggers’ was due to the mineral imbalances not myco-toxins (remember there are two causes of ‘staggers’).

Here is an example of what can happen if you don’t insist:

"Hello, I have watched your fb page for some time and taken careful note of your advice about types of grasses to feed horses for optimum results and calm and healthy horses.

Taking your advice from your web page I ordered new seed to be resown this coming spring. It has arrived in readiness - however I see the seed merchant could not provide Prairie Grass or Grazing Brome seed so substituted for 25kgs Nui Rygrass, 10 kg Emerald White clover, 4 Kg Relish ss Red clover.

I’m ready to tear my hair out about people who don’t follow instructions. I was assured that they were 'horse folk' too and they would substitute suitable seeds. I specifically gave them the list from your web page - Nothing in the list about rye grasses!!

I’m about in tears at the thought of what to do next. I would really appreciate your advice. The whole purpose of the resowing excersise was to make the whole place horse friendly grasses!

Why don’t people listen?!?!"

Field of white clover

An example of a paddock that was sown in (according to the seed merchant) ‘Horse Friendly Grass’!

Oxalate Grasses

Setaria. Paspallum. Kikuyu - These are Oxalate Grasses.

Oxalates are chemicals more abundant in warm season grasses, that latch onto calcium making the Calcium unavailable for the grazing animal to utilise.
It doesn’t take long for the resulting low blood calcium levels to cause the Parathyroid Gland to produce Parathyroid Hormone to tell the bones to release calcium into the bloodstream to make up the shortfall.

Calcium is vital to keep the heart beating, a job that, for obvious reasons, takes priority over maintaining strong bones.

If this process continues over a period of time and more calcium leaves the bones than is deposited back in, then a weak, porous skeleton results.
The trouble is you do not see this ‘demineralisation’ happening from the outside.

Horses exposed to oxalate pastures can start exhibiting signs of calcium deficiency within a couple of months of being moved onto high oxalate grasses. However usually it is more insidious with the first signs being vague and non-specific such as loss of weight and muscle tone and deterioration of coat and hoof quality.

If your horses are grazing these grasses, make sure that you are adding XtraCal to their daily feeds

Indie and Tawny grazing perfect grass

Perfect winter horse grass.


Kikuyu grass above and below

Resowing is a lengthy and expensive process so you don’t want to be doing it unless the grass you have is so unsuitable there are no other options.

Here are some aspects to consider...

We talk about ‘Horse-Friendly’ grass but what exactly is that?

It is grass that horses can consume every day, all year round, without developing any of the issues that horses grazing unsuitable grass inevitably do.
(See Health Check).

On your property, or at your place of agistment/livery yard:

  • The pasture grass may be suitable at some times of the year but not others.

  • The grass species present may be good but because there is no pasture management – the horses end up grazing short, green, stressed grass all year round, they are vulnerable to the changes in the grass which happen with the season and the weather.

  • Perfectly good grass can be rendered unsuitable because of fertiliser application or excessive harrowing.

  • The grass species are a good mixture of species but the ‘pasture’ is unsuitable because either clovers/plantain/cat’s ear/cape-weed or other broadleaf plants have become too prevalent.

The point of listing these scenarios is that resowing may not be necessarily the best plan. It could potentially be better for the long term to:

  • Eliminate the broadleaf plants from the grazing areas annually

  • Create some kind of ‘dry lot’ option where you can safely keep your horse
    *Where he isn’t cooped up in a little square
    *Where he has choices of shade and shelter
    *Where movement can be encouraged
    *Whereby some pasture management strategies can be implemented
    *Whereby in the event of really wet weather the pasture can be saved from being ‘trashed’
    *Where access to suitable grass can be ‘customised’ according to individual requirements if necessary

Years ago we thought that, to achieve calm, healthy horses, all we had to do was eliminate rye-grass and clover and re-sow with grasses like Grazing Brome, Prairie grass, Brown-top, Poa’s, and Timothy. Then all our troubles would be over - right?
Our horses would be able to graze all day long and not become ‘grass-affected’......

What actually happened was that, although we no longer experienced the hormonal issues or the mud-fever/sunburn problems associated with clover, the horses still got spooky, twitchy, agitated, footy, head-flicky and sometimes scary! Especially in spring and autumn and especially after rain.

Fast forward a few years after a steep learn curve about grass physiology. The take home message is that ‘stage of growth’ of the grass is equally and often even MORE important than ‘species’.

The potassium, Crude Protein & soluble sugar content of ANY grass species, ‘horse-friendly’ or not, are the nutrients we need to be aware of because when they are present in excess they place undue and cumulative stress on the horse’s metabolism.
They tend to cause issues for horses when the grass is

  • short and stressed because it is overgrazed

  • in rapid growth mode, (spring, autumn, after fires and drought-breaking rains)

  • green and lush

  • subject to consecutive cloudy days or frosts

  • overly harrowed

  • inappropriately fertilised

It is far more difficult to keep horses calm, healthy and moving properly in the long term IF THEIR PREDOMINANT FORAGE is any of the above because they will become ‘grass-affected’.

Whereas mature, fibrous grass of pretty well any species (Rye-grass and Tall Fescue being amongst the exceptions) is very compatible with keeping horses calm and healthy because grass at this stage of growth no longer has the huge requirement for potassium and nitrogen and has slowed down sugar production.

Therefore, if you, like most of us live in regions where grass stays green pretty well all year round, and you don’t have enough land to keep nice mature grass ahead of your horses then the most horse-friendly grass you can feed your horse is in the form of HAY! Hay, hay and more hay! Clover-free hay.

Yes it is a great step in the right direction to sow other species where possible in order to increase the bio-diversity and grow great hay but you still need to ‘manage’ how and at what stage you allow your horses to graze it.

If you would like your horses to be able to go out and graze NEXT spring, put aside a paddock NOW so that it grows slowly all winter and will be at a more mature stage of growth by spring and safe for at least some grazing time.

Paspalum seed heads


Paspalum in New Zealand and Australia can become a dominant grass in warmer regions, particularly during summer and autumn when most other grasses will have browned off.

The problem is that Paspalum harbours a fungus called Paspalum Claviceps manifesting on the seed-head as ‘ergots’ (which resemble mouse droppings). Ergots are chokka full of chemicals known as toxic alkaloids:  The Paspalum ergot ONLY affects the flower/seed-head, NOT the rest of the grass.  Roots, stem and foliage are free of this fungus and safe for livestock to eat.

So the grass itself is not toxic, but the seed-heads are a problem when parasitized by the ergot fungus which can produce toxic ‘pyridine alkaloids’ (nasty chemicals) in the little ‘mouse-droppings’ that appear in late summer or autumn.

*The best strategy, although not easy to achieve, is to keep it grazed so it doesn’t go to seed. If you mow or slash Paspalum, it just produces smaller seed-heads on shorter stems!

To date, I have never known of horses developing ‘Paspalum staggers’, likely because when Paspalum matures it becomes less palatable so hopefully they don’t consume enough and will go for other options. The little ergots however stick to the horses muzzle and legs and are liable to be ingested accidentally.

FYI: Affected animals become very excitable, start trembling, lose muscular control, stagger and even fall over. They recover in a few days if removed from the infected pasture.

*This can be done in short bursts of an hour or more a day so they are not constantly grazing the short green!

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