How to Control Lawn Moss: A Guide

Moss is a common problem in many lawns, especially in damp and shady areas. Moss can make your lawn look unsightly, uneven, and spongy. It can also compete with your grass for water, nutrients, and space, reducing the health and vigour of your lawn.

But don’t worry, you can get rid of moss in your lawn and prevent it from coming back with these simple and effective steps from Handy Andy Lawn Care.

Key Takeaways

• Moss in lawns is usually caused by poor growing conditions for grass, such as poor drainage, low soil fertility, acidic soil, shade, or mowing too short.
• To get rid of moss in your lawn, you need to remove it physically by raking or scarifying, and then apply a moss killer to kill any remaining moss and prevent it from regrowing.
• To prevent moss from coming back, you need to improve the growing conditions for your grass by improving the drainage, fertilising, liming, aerating, overseeding, mowing, and watering your lawn regularly and properly.
• You can also use organic methods to control moss, such as vinegar, baking soda, or iron sulphate, but these may have side effects on your grass and soil, so use them with caution and follow the instructions carefully.
• You can also reduce the amount of shade in your lawn by pruning trees and shrubs, or planting shade-tolerant grass varieties or ground covers in shady areas.

Step 1: Remove Moss Physically

The first step to control moss in your lawn is to remove it physically by raking or scarifying. This will help you get rid of the bulk of the moss and make your lawn look neater and smoother.

Raking is the simplest and cheapest method to remove moss. You can use a spring-tine lawn rake or a wire brush to rake over the lawn and pull out the moss. You can do this by hand or use a powered lawn rake for larger areas.

Scarifying is a more thorough and effective method to remove moss. It involves using a machine called a scarifier or a dethatcher, which has blades or tines that cut through the lawn and remove the moss, thatch, and dead grass. You can rent or buy a scarifier from a garden centre or hardware store.

The best time to rake or scarify your lawn is in late spring or early autumn, when the weather is cool and moist, and the grass is actively growing. Avoid doing this in summer or winter, when the weather is too hot or cold, and the grass is dormant or stressed.

Before raking or scarifying your lawn, you should mow it to a height of about 2.5 cm (1 inch). This will make it easier to remove the moss and reduce the stress on the grass. You should also water your lawn a few days before if the soil is dry.

After raking or scarifying your lawn, you should collect and dispose of the moss and debris. You can compost them, burn them, or put them in the green waste bin. Do not leave them on the lawn, as they can harbour diseases and pests, and cause more moss to grow.

Step 2: Apply a Moss Killer

The second step to control moss in your lawn is to apply a moss killer to kill any remaining moss and prevent it from regrowing. Moss killers are chemicals or organic substances that kill moss by drying it out, burning it, or changing the pH of the soil.

There are many types of moss killers available, but the most common ones are:

• Iron sulphate: This is a chemical that contains iron and sulphur, which react with the moss and turn it black and dry. It also lowers the pH of the soil, making it more acidic and less favourable for moss. Iron sulphate is often combined with a fertiliser to nourish the grass and improve its colour. You can buy iron sulphate as a powder, granule, or liquid, and apply it with a spreader or a sprayer. You should follow the instructions on the label and wear gloves and goggles when handling it. You should also avoid walking on the lawn or letting pets or children on it until it is dry, as it can stain your shoes, clothes, or skin.
• Baking soda: This is an organic substance that contains sodium and bicarbonate, which react with the moss and turn it brown and dry. It also raises the pH of the soil, making it more alkaline and less favourable for moss. Baking soda is a cheap and eco-friendly alternative to iron sulphate, but it may not be as effective or long-lasting. You can buy baking soda as a powder and apply it with a spreader or a sprinkler. You should use about 50 g (2 oz) per square metre (10 sq ft) of lawn and water it in well. You should also avoid applying it too often or too much, as it can damage your grass and soil.
• Vinegar: This is an organic substance that contains acetic acid, which reacts with the moss and burns it. It also lowers the pH of the soil, making it more acidic and less favourable for moss. Vinegar is another cheap and eco-friendly alternative to iron sulphate, but it may not be as effective or long-lasting. You can buy vinegar as a liquid and apply it with a sprayer. You should use a 5% solution of vinegar and water and spray it generously on the moss. You should also avoid applying it too often or too much, as it can damage your grass and soil.

The best time to apply a moss killer is after raking or scarifying your lawn, when the moss is exposed and vulnerable. You should also choose a day when the weather is dry and calm, and there is no rain forecast for at least 24 hours. This will ensure that the moss killer works effectively and does not wash away or drift to other plants.

After applying a moss killer, you should wait for a few days or weeks until the moss is dead and turns black or brown. You can then rake or scarify your lawn again to remove the dead moss and debris. You can also mow your lawn to a height of about 4 cm (1.5 inches) to encourage the grass to grow and fill in the gaps.

Step 3: Improve the Drainage

The third step to control moss in your lawn is to improve the drainage. Poor drainage is one of the main causes of moss in lawns, as it creates wet and soggy conditions that favour moss over grass. Improving the drainage will help your lawn dry out faster and prevent waterlogging and moss growth.

There are two main ways to improve the drainage in your lawn:

• Aeration: This is the process of making holes in the soil to allow air, water, and nutrients to penetrate deeper and improve the soil structure and drainage. Aeration also helps to relieve compaction, which is another cause of poor drainage and moss in lawns. You can aerate your lawn by using a tool called an aerator, which has spikes or hollow tines that pierce the soil and remove cores. You can rent or buy an aerator from a garden centre or hardware store, or you can use a garden fork or a pair of spiked shoes. You should aerate your lawn once or twice a year, preferably in spring or autumn, when the soil is moist but not wet. You should make holes about 10 cm (4 inches) deep and 15 cm (6 inches) apart, covering the entire lawn. You should also remove and dispose of the cores, or break them up and spread them over the lawn.
• Topdressing: This is the process of applying a thin layer of material over the lawn to improve the soil texture and drainage. Topdressing also helps to level the lawn, fill in the holes, and provide nutrients to the grass. You can topdress your lawn by using a mixture of sand, loam, and organic matter, such as compost or peat. You can buy ready-made topdressing from a garden centre or hardware store, or you can make your own by mixing equal parts of sand, loam, and organic matter. You should topdress your lawn after aeration, preferably in spring or autumn, when the grass is actively growing. You should apply about 2 kg (4.5 lbs) of topdressing per square metre (10 sq ft) of lawn, spreading it evenly with a rake or a brush. You should also water your lawn well after topdressing to help the material settle into the holes and the soil.

Step 4: Fertilise and Lime Your Lawn

The fourth step to control moss in your lawn is to fertilise and lime your lawn. Fertilising and liming your lawn will help to improve the soil fertility and pH, which are also important factors for moss control.

Fertilising your lawn will provide your grass with the essential nutrients it needs to grow strong and healthy, and to outcompete the moss. Fertilising your lawn will also improve the colour and appearance of your lawn, making it more attractive and resistant to moss. You can fertilise your lawn by using a lawn fertiliser that contains nitrogen, phosphorus, and potassium, which are the main nutrients for grass growth. You can buy lawn fertiliser as a granule, pellet, or liquid, and apply it with a spreader or a sprayer. You should follow the instructions on the label and wear gloves and goggles when handling it. You should also avoid over-fertilising your lawn, as this can cause problems such as burning, thatch, weeds, and diseases.