Mosses can be found from the Arctic region all the way through to the tropics and sections of the Antarctic. Even though they mostly live in damp, shaded areas in temperate climates, some survive in deserts while others live in bogs and streams. As a result moss can be categorised as a aquatic weed such as blanket weed.
In forests, mosses commonly form a mat that inhabits the ground or surfaces of rotting tree logs.
Mosses are capable of storing large amounts of water in their cells, but if a drought continues for an extended time, they become dormant until it rains. Most mosses reproduce asexually by fragmentation. Essentially, any part of the moss plant can grow and produce leaflike thalli.
While there are many ways to control moss, there is a single organic/natural product that is an effective moss killer, iron sulphate.
Iron Sulphate also called ferrous sulphate or sulphate of Iron is a type of salt that exists as a heptahydrate. Heptahydrate is a chemically combined compound that has seven molecules of water just the same as magnesium sulphate. Its chemical formula is FeSO4.
Iron sulphate is used in a wide variety of industries including the medical, manufacturing, and horticulture sectors. Iron sulphate is also used as a granular fertiliser.
Ferrous sulphate’s use as a moss killer helps to acidify alkaline soils to provide ideal conditions for a range of ericaceous plants. It is also effective and cost efficient means of controlling moss and algae and as an ingredient in both lawn sand and lawn dressings.
Iron causes moss to go black. In fact, iron sulphate causes a burn effect on the moss so that the plant becomes fragile and eventually dies. Because iron sulphate is good for use as a fertiliser, it will benefit your lawn and make it greener. Essentially, it has a selective mechanism that only targets moss.
An important key point to keep in mind is that moss does not kill lawns but grows on the surface of the grass. Over time, grass will have to try hard to compete for sunlight which can cause the lawn to go astray. Moreover, moss is an opportunist and thrives where grass does not.
Some key benefits of using this product are:
- The sulphate acidifies the soil and promotes fine leaved grass growth. High alkaline soil hurts grass growth.
- Controls unwanted moss that ruin the appearance of your lawn
- Reduces that chance of turf disease
- Fertilises the soil
Best Iron Sulphate Moss Killer
This ferrous sulphate of iron is the best and most popular one in the United Kingdom. It has rave reviews totalling close to 400 five-star ratings. It is a highly effective product and works to get rid of moss but keeps the lawn healthy. Furthermore, it has the power to make your lawn look greener.
How to use Sulphate of Iron
Before you begin treating your lawn or garden, you need to aerate the lawn to remove dead leaves and thatch. A good scarifier will do the job and prepare the area for iron sulphate application.
The two ways you can apply ferrous sulphate to your lawn and garden are through a spreader or a garden sprayer.
The best time to use iron sulphate is during spring or autumn.
Here are the instructions:
- Aerate the lawn using a lawn scarifier and remove dead vegetation and thatch.
- Choose whether you want to use a garden sprayer or spreader (check our garden sprayer reviews or choose the evergreen spreader). The Evergreen spreader is meant to spread granular lawn products so it is a perfect match of iron sulphate. From our standpoint, we do not recommend using a garden sprayer because often the salts from iron sulphate do not mix well with water and result in a clogged nozzle.
- If you choose to use a sprayer, then pick a day when there is little wind and ensure rain will not fall within a 24 hour period. To use, measure 17 millilitres of ferrous sulphate and mix it with 4.5 litres of warm water. This mixture will be able to treat 200 square metres. Next, position your sprayer and treat affected areas.
- If you choose to use a spreader, then you will need to water the treated area thoroughly or let the rain do it for you after using. No weather restrictions are using this method. To use: separate the iron sulphate into two halves, fill the spreader with enough substance and begin performing the spreading over the lawn.
- After the moss is dead, re-scarify the lawn or use a rake to remove the excess debris.
- Check the acidity of the soil with a soil pH test kit. The best soil pH for grass is between 6.5 to 7. If your soil pH is above 7, it is too alkaline, and if it is below 6.5, then it is too acidic.
- Apply five to ten pounds of lime per 100 square metres to neutralise the soil’s pH level (given the test indicates an acidic soil).
- Add organic compost to fertilise the lawn or garden.
Safety and Precautions
Following these pointers to maximise safety when handling ferrous sulphate
- Wear protective gear including overalls, gloves, goggles, and face mask
- Mix the iron sulphate in a separate container, then fill sprayer
- Handle carefully and avoid drift to concrete patios, paths, and driveways.
- Read the safety data sheet supplied with your purchase.
Laws and Legislation Controversy
There seems to be a workaround iron sulphate manufacturers are using to avoid legislative action to their products. By law, every form of pesticide, whether it be a herbicide, fungicide, or moss killer requires registration with the UK Health and Safety Executive. The catch is iron sulphate can be marketed as a fertiliser or a moss killer.
Companies who market iron sulphate as a moss killer must first get government approval. However, companies who market iron sulphate as a fertiliser do not need any permission whatsoever. In theory, the ferrous sulphate in these products is the same but are marketed for a different purpose and different price.
Moss does not compete well with a healthy lawn. And if you use ferrous sulphate to create a lush garden or yard then you will get your money’s worth. However, when treating moss one should take all the contributing growth factors such as season, climate, shade levels, rain levels, soil type, and nutrient content of the soil into consideration. By approaching garden problems in a holistic way, you can ensure your success as a gardener.