Seed & Turf Quantities

How to Plant Grass Seed for Guaranteed Success

You will need:

  • Viable seed harvested and bagged within the previous 12 months. Lawnsmith seed is guaranteed fresh
  • A seed bed that is not compacted and contains air
  • Warmth, ideally above 12 degrees ground temperature
  • Fertiliser – a Starter Fertiliser for new lawns or a Seasonal Fertiliser for seeding patches or after scarifying
  • Constant moisture for the first 2 weeks at least

Procedure for Sowing Grass Seed

This general procedure is suitable for a new lawn, over seeding or patching prepared ground:

  • Time with warmth in mind – generally April to September
  • If the weather has been dry, water the area thoroughly for several days prior to seeding to build a reservoir of moisture in the soil. Leave the surface to dry a little before walking on it to plant seed
  • Hard ground is usually dry ground – if you can push a screwdriver at least 10cm into the soil with ease it should be moist enough
  • Lightly score the soil surface with a rake no deeper than a few millimeters
  • Split the seed into two lots if you are confident of spreading evenly, otherwise split into four equal lots
  • Spread the seed by hand or spreader working in a different direction for each lot e.g. north to south, then south to north and east to west etc. This will ensure even coverage. A smaller than recommended setting (say 1/3 open) on the spreader will prevent you running out of seed too quickly but means more trips up and down the lawn
  • Very lightly rake or brush the area after spreading the seed to make sure the seed is mixed with the soil
  • Good seed to soil contact is essential so lightly roll, tread or firm the area as best you can to press the seed into the soil surface. It is not necessary to add soil unless top dressing the lawn
  • Water lightly and frequently so that seed is not washed away but the area does not dry out. This is normally once or twice a day but may mean watering more often in dry windy conditions
  • To avoid the hassle of watering and protect from frost, drying and birds try this. Heavily water the area before seeding then, after seeding, cover with a sheet of polythene pinned in place with bricks or pegs. Remove it once green shoots are an inch high then start watering. Very large polythene rolls can be obtained cheaply from builders’ merchants etc. Do not use in hot weather or you will cook the grass!
  • To speed growth once germinated your ‘starter’ (new lawns) or seasonal fertiliser (over seeding) should be added. This can be done on the day of sowing for convenience or within 2 weeks of germination. Do not use ‘weed & feed’ type products.

Spreading Grass Seed

Because of the elongated shape of grass seed it does not 'flow' consistently through rotary or broadcast spreaders. This means that though a spreader is an excellent method for spreading seed, settings are unreliable which is why we suggest a one third open setting to start and applying in several lots to ensure consistent even coverage.

Procedure for Seeding Patches

If all you need to do is seed a few badly damaged patches then follow the procedure above but lightly sprinkle 10 to 20 seeds per square inch into the patches. Watering before and after and fertilising remains the same.

Mowing New Grass Seedlings

If patching or over seeding you need to keep the existing lawn in check so mow before seeding then mow on your normal schedule (perhaps every 7-10 days) on a dry day on a high setting with sharp blades.

If mowing a new lawn start when grass gets to 3” (7 to 8cm). Once again mow on a high setting on a dry day with sharp blades. In either case lower the setting gradually after 3 months if you wish.

Related video for this article