Lawn aeration & aerators
What is lawn aeration
Lawn aeration is the process of creating air channels in the lawn to promote air movement within the soil or root zone. Grass that grows on a well aerated soil is more likely to be in a healthy condition. A healthy lawn that receives regular lawn aeration can withstand many common lawn care problems such as drought, moss, weeds, disease and more. A lack of oxygen or air in the soil leads to soil compaction and in turn grass growth is weak and patchy. A weak lawn will suffer from all of the problems mentioned previously, therefore if you desire a quality lawn, a regular lawn aeration program should be employed.
The benefits of lawn aeration
We have already mentioned that a lawn that receives regular aeration will be significantly healthier than one that receives little or none. However lets look at the benefits of lawn aeration in a little more detail:
- Relieves soil compaction - Over a period of time soils become compact due to traffic such as people, garden machinery and vehicles. This causes all of the remaining air to be squeezed out to the detriment of the health of the lawn. This when the soil becomes compacted. With little or no air the lawn becomes thin and weak, giving other lawn care problems an ideal environment to invade the lawn. A regular aeration program helps relieve soil compaction and maintain a healthy vigorous lawn.
- Improves soil and surface drainage - As lawn aeration creates holes into the soil it naturally helps remove any surface water and improves the soil drainage by encouraging the water to move through the soil.
- Encourages improved root depth and drought resistance - With regular lawn aeration comes increased air space in the soil. This in turn helps the roots penetrate deeper into the soil with the knock on effect being improved drought resistance.
- Encourages a healthy population of micro organisms - A healthy soil will contain a high percentage of micro organisms. These organisms perform many vital functions in the soil. These functions include the breakdown of organic matter or thatch, degradation of toxic chemicals and the suppression of the bacteria that causes lawn and turf disease. These micro organisms thrive in soils that contain a high percentage of air, in fact if the soil is deficient of air, it will have an adverse effect on the micro organism population.
- Breaks down and removes thatch in the lawn - We have already discussed how lawn aeration encourages micro organisms, which helps breakdown the thatch layer. Lawn aeration in the form of hollow-tining can also be employed to physically remove thatch. Hollow tines are hollow tubes which are punched into the lawn and in turn remove cores of thatch and soil.
- Aids the penetration of lawn care products and materials - Over the course of the lawn care calendar many products are applied to the lawn. Some of these products are more beneficial if they are allowed to penetrate into the root zone or soil. Tasks such as top dressing, over seeding, wetting agent treatment and irrigation all benefit from lawn aeration prior to their application.
- Reduces the incidence of lawn disease - Lawn aeration in some cases can help reduce the effects of lawn disease by helping correct the conditions favoured by the respective disease. Be it relieving soil compaction, improving drainage or reducing surface water to promote a dry foliage on the grass.
When to aerate a lawn
Although lawns can be aerated at any time of the year depending on surface and soil conditions, spring and autumn are the two most common times. Ideally early autumn is preferable to spring. However it can be carried out during both, especially if your lawn is suffering from problems that can be remedied with aeration.
The reason autumn is preferable is that aeration is usually carried out during the autumn program, as this compliments the other operations carried out in this program. Lawn aeration would normally follow moss treatment (if needed) and lawn scarification as this creates a good seed bed prior to over seeding and top dressing.
However over seeding and top dressing is sometimes undertaken in the spring program, especially if the lawn is very thin after moss removal is completed.
There can be other reasons for aerating during the year. Shallow spiking would aid wetting agent and water penetration during periods of drought.
Lawn aeration should only be undertaken during suitable ground and soil conditions. Ideally the soil should be moist so the machine or implement being used can penetrate into the soil without any problems. Avoid aerating when the soil is very wet or waterlogged as this can have an adverse effect on the soil.
It is also advisable not to aerate if the ground is too hard and dry, as you may damage your equipment. However shallow spiking that just pricks the surface to aid water penetration would be the exception to the rule in this case.
Different aeration tine types
When we talk about aeration types we are referring to the various types of tines used for aerating the lawn. These can include hollow tines, slit tines, cross head tines, chisel tines and solid tines. The two most commonly used tines on lawns are hollow and solid tines and it is these that we shall concentrate on.
- Hollow tines - These tines are hollow tubes which physically remove cores of thatch or soil from the lawn. They are particularly useful if your lawn has excessive thatch. Hollow tining is also more beneficial if a large amount of top dressing is to applied to the lawn. This is because hollow tining allows more of the top dressing material into the tine holes than conventional aeration.
Hollow tines are also more effective at reducing compaction than conventional tines, as the holes produced allow the ground to expand and compaction is relieved. Ideally hollow tining should only be used during periods of growth to encourage the holes to recover quicker.
- Solid tines - As their name suggests these tines are solid, a perfect example could be a garden fork. These tines are ideal for general aeration where thatch removal and top dressing penetration are not the primary goals.
How to aerate the lawn
When aerating the lawn either with a hand fork / implement or a purpose built machine there are a few rules to follow. Aerate the lawn so the tines create a square pattern on the lawn (In many cases if using a powered machine the operating speed of the aerator will be pre set).
Try to aerate the lawn to the maximum depth that the machine will allow. Most powered lawn aerators only aerate to a maximum depth of 4 and 6 inches or 12 - 15cm and for most lawns this is fine for them to remain healthy. However it is worth noting that grass roots can penetrate far deeper than this given the right soil conditions.
Types of lawn aerator
Lawn aerators fall into two different categories, hand held or hand powered implements or powered lawn aerators. Which type you use will depend on the size of your lawn or how fit and energetic you are.
- Hand held and hand powered implements - These type of aerators are ideal for small lawns and tight confined spaces. They can range from a simple garden forks and hand held hollow tine forks to pushed aerators where the tines are mounted onto a cylindrical drum. However care should be taken when using the push type aerators are they are not known for being very robust and are prone to breaking.
- Powered or towed lawn aerators - These machines are great for larger lawns where space is not an issue. They are often powered by a petrol engine or towed using a garden tractor or similar. The tines are in certain cases interchangeable. The downside to this type of aerator is the purchase price, they are very expensive. However hiring a lawn aerator in many cases is the best option as the usage frequency doesn't justify buying one.