How to overseed your lawn with new grass seed

Thinking of overseeding your lawn? Here are the reasons why you should and some quick tips on how to overseed your lawn.

The grasses in any lawn can thin over time, causing bare patches and weak areas. This can be caused by many reasons including compaction, increased shade from shrubs or trees growing over the lawn, minor changes in the acidity due to fertilising or an increase in the thatch levels in the lawn, causing suffocation of the grass.

These slow changes in the environment can be very difficult for a grass plant to adapt to and tolerate, so they may weaken and eventually die.

This can be a good thing for a neighbouring grass plant in the same lawn, as they may take advantage of the extra space and start to spread. However, this is spreading behaviour is undesirable in most lawns as it leads to untidy sideways growth.

A deterioration in the mix of grass species can also mean that areas of your lawn can become “patchy” in colour. One species of grass dominating one area and another species in a different area. So for home-owners that are aiming for a perfect lawn, this is far from desirable.

Thankfully, many of these issues can be addressed by a simple lawn overseeding treatment

Overseeding is basically the process of injecting new grass into the existing turf by planting seed amongst the existing grass plants.

This treatment has the benefit of introducing a uniform colour of grass throughout the entire lawn. Evening out any tone changes from previous lawn repairs, areas of new lawn or additional patches of re-turfing. It also allows the lawn owner to plant a different species of grass that may be better suited to the lawn, such as wear-tolerant, shade-tolerant or a much finer grass to improve the overall look.

The very best time to overseed your lawn is straight after a heavy scarification treatment in the autumn. This is when the lawn will be at its thinnest and the soil will be exposed, planting the seed most effectively and, as the soil will still be warm and damp, it will have the best chance of germination.

If you don’t feel that your lawn needs a full scarification, then it is possible to overseed your lawn without scarifying. It is recommended that the lawn is checked for levels of thatch first. A thick layer of organic matter on the surface of the lawn will dramatically inhibit seed germination. This will reduce the effectiveness of overseeding.

Use a spreader to overseed your lawn

When overseeding your lawn, the only way to ensure even coverage is to use a good quality spreader. Choose a calm day, as grass seed is very light, you don’t want it blowing into your flower beds. Measure the lawn and weigh out the correct amount of seed. Then add half of it to the spreader and spread the seed in one direction until it has all gone. Then go in another direction with the other half. This will minimise the risk of missing areas between rows.

After spreading your seed, it is a good idea to work the seed into the ground. This helps to plant it. This can be done with a back of a rake, or ideally with a drag-mat. Run it back and forth over the lawn to help get the seed into contact with the ground.

It is then advisable to top dress your lawn with a suitable material, to level your lawn and to help plant the seed further. The extra covering also helps hide the seed from hungry birds!

I stock a large range of the highest quality lawn seed varieties. I would be happy to advise you as to the most appropriate grass seed to overseed your lawn.

Kris Lord
The Lawn Man