Pasture Management
for
Horses

Weed Control

Before talking about weed control it would be useful to consider how to avoid weeds becoming established.
Many weeds require bare ground and light to germinate. This includes ragwort.
Weeds will usually be discouraged by encouraging the grass to grow, therefore look at the whole management of your pasture, not just your weeds.
If chemical control is to be used, get professional advice and employ a professional to do the job as specialist skills and training are required. In all cases, any instructions on a spray container must be followed. Chemical weed control may be by the following methods.

1. Overall Application

This method will use a crop sprayer that will spray the whole paddock or an area of it. The crop sprayer may range in size from a large self propelled machine with a wide boom carrying the spray nozzles, a tractor mounted machine with a 12 metre boom, or a sprayer mounted on an "all terain vehicle" (ATV or quad bike) with perhaps a 3 metre boom.
The sprayer will have a tank holding a mixture of the spray chemical and water which is pumped under a pressure of 2-3 bar to the spray nozzles on the spray boom. The quantity of water required will usually be around 200L/Ha and the spray chemicals will be selective weedkillers (chemicals capable of killing weeds but not grasses, unless it is required to totally destroy the sward prior to a reseeding operation). There are also selective weedkillers available which will not harm clover though all weedkillers are likely to harm other "desirable herbs".
The benefits of this method are the accuracy of application (provided the operator is competent).

2.Spot Application

This method will involve the use of a knapsack sprayer (small sprayer carried on the persons back, having a hand pump and hand lance with a single spray nozzle and control valve). Individual weeds or patches of weeds such as thistles or docks may be sprayed by this method.
The benefits of this method are that it may be suitable for controlling the occasional small patch of weeds.

3.Weed Wiper

This method will use a wick soaked in weedkiller, mounted on a short boom trailed behind a tractor or ATV. The height of the boom is controlled to only allow taller plants to come into contact with the wick. This can be particularly usuful for controlling tall perennial weeds such as thistles, docks and nettles.
The benefits of this method are that the chemical and application costs will be considerably cheaper than overall application but can still be very effective in the right situation.

Considerations with all types of chemical application.

1. This is a speciallist job usually requiring the operative to be suitably qualified.
2. Always follow any instructions on the spray container.
3. Horses will not be able to graze the paddock for some weeks afterwards (as specified on the spray container) to be safe from any poisonous effect of the spray chemical.
4. If poisonous plants were present, it will be necessary to keep horses out of the paddock for a much longer period, unless these plants can all be removed.
5. It may be necessary to keep the horses out of the paddock for a few weeks prior to the application to ensure sufficient weed growth to absorb the spray, and sufficient grass growth to compete with the dying weeds.
6. In general, annual weeds are best controlled when small, and perennial weeds just before flowering.
7. It will be necessary to have a period of at least 4 hours without rain after the application to allow the chemical to be absorbed.
8. Good growing conditions are required - strange as it may seem, but weeds generally need to be actively growing.