Ammonium Sulphate & Clover in Lawns

Trifolium repens L,  White Clover can be seen as both a friend and foe of lawns. Clover is part of the legume family and has the ability to add nitrogen to the soil. This nitrogen is great for boosting grass growth as it is essential for development to the green tissue in plants. Other familiar plants that can carry out this process include honeysuckle, beans and peas. The process is known as nitrogen fixation and is the main reason why many farmland grass mixes include about 10% clover seed. While clover is a natural way of adding Nitrogen to the soil, Ammonium Sulphate is a synthetic way of adding usable Nitrogen directly to the soil

For those of us who want a pristine lawn free of weeds and all unsightly things then clover is just another weed and we want it out. There are a number of ways to reduce clover build up on lawns and the obvious option would be to use a lawn weed killer. lawn weed killers with the active ingredient dicamba, dichlorprop-P is a good chemical control option. This can be found in dicophar lawn weed killer and should be applied from mid spring until late summer for best results.

Before mentioning the benefits of using ammonium sulphate to control clover on lawn we will outline some other ways to reduce clover build up:

Raking your grass prior to cutting

This will raise all the spreading clover stems to the surface which can then be cut and removed by the lawnmower

Collect your cuttings

Clover self seeds very quickly, so regular cutting, while removing the cuttings is essential to prevent and reduce clover from reproducing

Cutting of grass

Ensure you cut your grass every 10 days and don’t scalp or cut too short as this will kill patches of lawn

Feed with phosphorus in Autumn.

Grass growth stops in late autumn, but roots continue to grow. Feed lawns in autumn with an autumn lawn feed or fertiliszer high in Phosphorus, i.e. 5:20:10

Using Ammonium Sulphate to Control Clover

Clover does not like Ammonium Sulphate for the following reasons:

Ammonium Sulphate reduces soils pH. Clover likes a pH of about 6.4 which is an alkaline soil. The more Ammonium you add the more acidic a soil becomes and this is not suitable for clover

Ammonium Sulphate is Nitrogen. The more Nitrogen you add to the slow the lower the rate of Nitrogen fixation. As clover works with bacteria in their roots to fix Nitrogen, this loss of this process slow down clover growth

Ammonium Sulphate is great for grass. Ammonium boosts grass growth as it is needed for foliage development, the more you add the better your grass will grow and so the quicker it will out complete the clover

When applying Ammonium Sulphate there are a few points to remember before application:

Rate of application to control clover: 15gm per m2

When to apply: Start in mid spring and continue over the summer every 6 weeks

How to apply: Ammonium Sulphate can be applied in its powder or liquid form. It is essential to ensure an even application. This can be achieve be mixing the product through sand or topsoil before applying