Fairy Rings in the Lawn

Fairy Rings which are caused by fungi start to show signs of activity during the end of spring or early summer. They are easily recognisable with distinct dark green rings and/or fruiting bodies including mushrooms, toadstools and puffballs. The rings can be full or part circle.

Although there are thousands of types of fungi that cause these rings, there are in fact only 3 types of Fairy Ring, each having different characteristics. Fairy Rings start from a central point and gradually increase in size, with the rings getting larger as time passes. In most cases they increase about 80mm - 150mm in size each year.

Fairy Rings degrade the organic matter in the lawn, it is then broken down by micro organisms and released as nitrogen. The nitrogen is then made available for plant uptake, giving the lawn its distinct dark green ring.
They can be found in all types of lawns and turf, including luxury lawns, golf greens, sports fields and neglected turf.

There are 3 types of Fairy Ring.

• Type 1 fairy ring: This type of Fairy Ring is the most destructive and damaging as it produces a ring of dead grass. The dead area can contain fruiting bodies in the form of mushrooms, toadstools and puffballs. If a section of soil is removed from the dead area, white thread or hair like structures called mycelium will be visible in the soil. Mycelium is hydrophobic (water repellant) and it is this that produces the dry patch, causing the grass to die.
• Type 2 fairy ring: Type 2 fairy rings are identified by their dark green rings, with or without fruiting bodies. In fact it is similar to a type 1 fairy ring without the dead ring of grass. At worst this type of ring can appear unsightly with its lush growth, accompanied with fruiting bodies.
• Type 3 fairy ring: The most inconspicuous type of Fairy Ring, as the dark ring of grass is absent. Only the ring of fruiting bodies will be visible at different times of the year. The least damaging of the 3 types.

Control of Fairy Rings
Fairy Rings can be masked with applications of nitrogen when they appear. Nitrogen produces dark green grass growth helping the remaining lawn blend in well with the Fairy Ring. However it is important to apply excessive nitrogen, as it can lead to other lawn or turf problems.

If you are dealing with a type 1 Fairy Ring regularly soaking the infected area and treating it with a wetting agent may help. However this should be undertaken before the soil gets too dry, or it may prove very difficult to re-wet.

The final option is to remove the Fairy Ring from the lawn, golf green etc, by digging it out. Remove all of the soil from inside the ring and 500mm from the outside edge the ring, this needs doing to a depth of 300mm.

It is important not to drop any of the infected soil onto the healthy turf, so take extreme care when doing this task. Replace the soil that has been removed with fresh soil and re-seed. This method is only recommended as a last resort.

Although fungicides are available for Fairy Rings results may be mixed and in many cases unsuccessful. Many gardeners can accept types 2 & 3, it is type 1 that gives the most problems.

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Soil Compaction in the Lawn

What is soil compaction

Most lawns will have or will experience the affects of soil compaction during their lifetime. All soils require a certain percentage of air in order to support a healthy lawn.

Soil compaction occurs when the majority of the air is squeezed out of the soil by excess traffic. The traffic can include garden machinery such as mowers, vehicles like cars or people using the lawn.

The more traffic the lawn receives the greater the compaction, is likely to be and the soil particles are pushed together reducing the amount of pore space available for air.

Generally speaking soils with a high content of clay are more prone to compaction than sandy soils. This is because clay has a smaller particle size than sand and the air is squeezed out more easily, especially when the soil is wet.

When soils become compacted the following happens:

• Air space is reduced.
• Root growth is restricted and shallow rooted weed grasses invade at the expense of the deeper rooted desirable grasses.
• Drainage is impeded and water logging and puddling become the norm.
• As root growth is shallow, then the lawn becomes very susceptible to drought conditions.
• The lawn is open to attack from pests such as broad-leaved weeds and disease, as growth is likely to be thin and the grass plant will be unhealthy.
• As the grass becomes stressed due to soil compaction, nutrient uptake is generally poorer than on healthy turf.
• The thatch layer will build up quicker, as the micro organisms, which breakdown the thatch in the lawn, require air to survive.

All of the above symptoms and conditions, result in a weak lawn and something must be done to restore the lawn to its former health.
A good way to test if you have soil compaction is to push a garden fork or soil profiler into the lawn. If there is too much resistance, you may have compaction and steps will have to be taken to address the issue.

Controlling soil compaction

Compaction can be relieved using some form of lawn aeration. In fact regular aeration should be carried out at least once a year on most lawns. Clay soils may need additional aeration they are more at risk to compaction than light sandy soils.

There is a variety of aeration equipment and tools available to the amateur gardener to combat soil compaction. These include hand forks, hand corers and powered spikers and corers. For more information on these you can visit our lawn aeration and lawn aerators page.

Once you have successfully controlled compaction it is important to prevent it from returning by aerating the lawn on a regular basis. Aerate at least once a year, twice if you soil is prone to soil compaction.

Aeration is regularly carried out on sports turf such as football fields, golf and bowling greens. Turf professionals know the ills of soil compaction and do something about it prior to it becoming a problem. Sports turf receives a large amount of traffic and regular routine aeration is required to prevent soil compaction.

Turf professionals have a variety aerators at their disposal. These aerators include verti-drain machines which heave shatter the soil, hollow tine machines which remove cores of thatch and soil, shallow spikers, air injection aerators and more.

Each machine has its own benefits and uses in the battle against compaction. Another important factor is that turf professionals vary the depth of aeration to stop a pan forming in the soil.

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Sulphate of Iron on Lawns

Sulphate of Iron is one of the most widely used products in the professional turf care industry. This is because it is very versatile, it had many uses and is also relatively cheap to purchase. This product is primarily used for controlling moss during the spring months, however it can also be used to help prevent certain lawn diseases and discourage earthworm activity, thus preventing worm casts.

It is also a great product for giving the lawn a quick green up, particularly during the winter months when the grass is looking yellow and tired.

Moss Control

For many generations sulphate of iron has been the best product for controlling moss in the lawn. It is one of the main ingredients in lawn sand. Lawn sand is made up of:

• Sulphate of Iron - This product controls the moss in the lawn. 
•  Sulphate of Ammonia - This is a nitrogen based fertiliser which creates rapid grass growth, thus helping the lawn recover rapidly once the moss has been killed and removed. 
•  Sand - This is simply used as a carrier to bulk the product up. This helps with the application of the product.

Lawn sand should be applied during the spring time when grass growth is just getting started. After 2 weeks the moss should have been killed sufficiently for it to be removed from the lawn with a powered lawn rake or scarifier.

Sulphate of iron is also Incorporated into many other lawn feed products used for moss control. Most fertiliser companies have weed feed and moss control products. The vast majority of these products contain sulphate of iron.

Worm Suppression 

Worm casts can be a major nuisance during the autumn and winter months when the conditions are wet and humid. As Iron sulphate acidifies the surface of the lawn this helps discourage worm activity, as worms don't like acidic conditions.

Sulphate of Iron applied every 4 - 6 weeks at a rate of 10g/m2 during periods of worm activity, can help reduce worm numbers thus reducing the number of worm casts. Worms tend to be more problematic on heavy clay soils rather than lighter sandy soils.

Disease Prevention

Although turf diseases are not an issue on most typical garden lawns they can be a major headache on closely mown sports turf such as golf and bowling greens. For these reasons sulphate of iron is also regularly used in conjunction with turf fungicides to help prevent and control disease, especially fusarium patch disease.

Applying this product every 4 - 6 weeks at 10g/m2 will help prevent any fusarium patch disease problems.

Application Methods

Sulphate of Iron is readily available in a powder form, and although it can be applied in this form it best dissolved in hot water and applied through a sprayer or a watering can. It is also important that it has dissolved properly as it can be prone to blocking sprayer nozzles if it hasn't been mixed enough.

Take care when mixing, as Sulphate of Iron can stain clothes or concrete path ways. If any solution is splashed onto your clothing wash them separately to other garments as it may contaminate them too.

For sulphate of iron based products such as lawn sand and weed, feed and moss control products always follow the instructions on the packaging.

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