Why over-seed a lawn.
- Improve the lawn characteristics – such as shade tolerance, drought tolerance, disease resistance, wear tolerance or generally improve the quality of grass plants within the lawn.
- Repair the lawn – and increase the sward density after renovation has left the lawn looking thin and weak.
- Encourage a harder wearing lawn – that will withstand a n increase in traffic and wear and tear.
- Encourage finer grasses – such as bents and fescues if your goal is to have a fine luxury lawn.
How to over-seed a lawn.
- Over-seeding is best carried out after some form of aeration and/or scarification as both of these operations encourage the seed to come in contact with the soil.
- Prior to over-seeding mow the lawn a little shorter than usual, this will help the seed to make better contact with the soil and will also make top dressing easier to apply and spread.
- Spread the seed to the lawn, ideally using a spreader but applying it by hand is fine just be sure to spread it evenly as best you can. I recommend that the application rate for over-seeding your lawn be 25g/m2.
- Apply a light top dressing (layer of sand/soil mix) to your lawn. Work it into the sward with a brush, lute or the back of a rake, this will help protect the seed, improve seed/soil contact and retain moisture.
To get the best results from your over-seeding it is worth noting a few simple points that will help with establishment.
- After your over-seeding program is complete it is important to keep the soil moist to encourage strong germination.
- Keep of the area as much as possible until the plants are strong.
- If your lawn has not been fed recently it would be very beneficial to the new seedlings to apply a suitable feed. Feeding your lawn is most beneficial after germination compared to prior, if your lawn is fed after germination it helps to reduce the competition from existing grass plants.
- Mow the lawn as normal raising the height of cut just slightly. Be sure to have nice sharp blades so the grass plants are cut cleanly (blunt blades tear and pull at the grass causing damage). Do not allow the new seedlings to grow too long before mowing as this will cause unnecessary stress.
Further tips for successful over-seeding.
Over-seeding into an established lawn can prove quite difficult as the new seedlings are having to fight for space, light, nutrients and moisture. However there are several factors that influence how successful your over-seeding program is. These are:
- Soil compaction – New seedlings will find it difficult to establish within a soil structure that is suffering from compaction as root development will be impeded, the soil will lack oxygen, drainage will be poor all to the detriment of seed establishment, this can be remedied by a suitable aeration prior to over-seeding.
- Excessive thatch accumulation – thatch is a layer of dead and living organic matter situated above the soil, this layer is soft and spongey. Seeds that germinate within the thatch layer do not establish well.
- Soil temperature – Grass seeds need warm soil temperatures to germinate well, soil temps above 4degrees and the seeds will germinate but the warmer the soil the better the results.
- Soil moist content – Grass seeds need moisture to germinate, it is important to remember that once the seed is moist it must stay moist for the next 3 / 5 days for successful germination.
- Seed/ soil contact – Just be sure that there is sufficient seed / soil contact and your over-seeding will be successful.
- Correct seed mixture and maintenance – All environments are different, be sure to have chosen the correct mixture for your environment and future usage. Be sure to maintain it correctly, regular mowing at the desired height of cut, regular fertilizer applications, water when dry and enjoy it.
- GRASS SEEDS GERMINATE IN SOIL TEMPS ABOVE 7 DEGREES – THE WARMER THE SOILS THE QUICKER THE GERMINATION.
- GRASS SEED GERMINATION RATES VARY FROM SPECIES TO SPECIES – BETWEEN 5 AND 21 DAYS
- GRASS SEED NEEDS CONTACT WITH THE SOIL. SEED / SOIL CONTACT = GERMINATION