How to Water Grass Seed

If you haven't already, please read All about Grass Seed Germination to fully understand why this watering method is so essential for the adequate growth of grass seed.

Checking Soil Moisture Before Seeding

Once the ground is prepared, check that there is plenty of moisture. It should be moist down to at least 10cm. You can check this by opening a small hole and checking that the soil is the same dark colour and has a stickiness to it that water imparts. Your hands should get dirty quickly. You don’t want boggy or saturated!

If you use a polythene covering to protect your seed, follow the pre-seeding watering step and only start watering again after removing the cover. This will be at 1” to 2” (2.5-5cms).

Pre-Seeding Watering Techniques

If you’re not happy, but it is moist enough, start watering the prepared ground for several days. You want it wet but not muddy. Now, let the surface dry for half a day so you can walk on it without the soil sticking to your shoes. Wear smooth-soled shoes to reduce disturbance of the soil surface.

Watering Immediately After Sowing

Get your seed into the ground and immediately give it its first shower. As in the top image, a fine spray pointed upwards showers the grass like light rain. You don’t want a heavy jet of water or too much water that starts moving the seed around. A light shower to wet the surface is all that is needed.

Watering During Grass Seed Germination

You must not let the seed dry out, so depending on the weather, you may not need to water at all. However, if you encounter a warm, dry spell, you may need to water every few hours.

Once again, watering should be like a light shower to wet the surface. Stop when pooling starts.

Watering Once Grass Has Sent Root Shoots 

At this point, the grass seed has sent down root shoots, and if it doesn’t get moisture at this stage, it will shrivel and die, and you will have to start again. Keep watering as in the previous step until you see a green sheen across the soil surface.

Watering Once Green Shoots Appear

Give yourself a pat on the back; your seed is now out of intensive care. Be aware that not all your seeds will germinate; therefore, frequent watering is still necessary. Your soil will start stabilising with the new seedlings so you can water more heavily and less frequently.

Watering Grass Seedlings (2-3cm)

This will happen quickly, mainly if you are wise enough to use a pre-seeding fertiliser. If you’re overseeding, a seasonal fertiliser would be more appropriate and is best applied now or in the next week.

Continue to water daily, but do so a little more deeply.

Watering Grass Seedlings (5-8cm) and First Mowing

It's time to give the lawn its first cut! Do not water the lawn beforehand, and allow it to dry slightly. Mow in the afternoon on a dry day with a high setting and sharp, clean mower blades. Mow slowly, with no racing or sharp turns; everything is soft and tender. Give the lawn a good watering afterwards and continue watering every other day until the next cut.

You now have a New Lawn

Water the lawn at least once a week for a few weeks and more often if the weather is dry. The lawn will now thicken with regular mowing, which should still be done weekly. Keeping the mower on a high cut throughout the first summer will help the roots grow deep into the soil, reducing the need for watering.

See Mowing the Lawn and also Watering the Lawn