How to Water Grass Seed
To get a full understanding of why this watering method is so important please read All about Grass Seed Germination if you haven’t already done so.
Check for Good Moisture in the Soil
Once the ground is prepared check there is plenty of moisture in the ground. It should be moist down to at least 10cms. You can check this by opening up a small hole and checking the soil is the same dark colour all the way down and has a stickiness to it which water imparts. Your hands should get dirty easily. You don’t want boggy or saturated!
If you are going to be using a polythene covering to protect your seed, then follow the pre-seeding watering step then only start watering again when you remove the cover. This will be at 1” to 2” (2.5-5cms).
If you’re not happy 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 that you can walk on it without the soil sticking to your shoes. Wear smooth soled shoes to reduce disturbance of the soil surface.
The Day of Sowing your Grass Seed
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 before Germination
You absolutely must not let the seed dry out, so depending on the weather you may not need to water at all but if you hit a warm dry spell you could be watering every couple of hours!
Once again, any watering should be like a light shower to wet the surface. Stop when pooling starts.
Grass Seed Germination
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 have to start again. Keep watering as in the previous step until you see a green sheen across the spoil surface.
Green Grass Shoots Watering
Give yourself a pat on the back, your seed is now out of intensive care. Be aware though that not all of your seed will have germinated so frequent watering is still required but now your soil will start to stabilise with the new seedlings so you can water a little more heavily and less frequently.
Grass Seedlings 2-3cm
This will happen very quickly particularly if you were wise enough to use a pre-seeding fertiliser. If you’re over seeding, a seasonal fertiliser would be more appropriate and is best applied now or in the next week.
Continue to water daily and a little more deeply.
Grass Seedlings 5-8cm
Time to give the lawn its first cut. Do not water before hand and let the lawn dry a little. Mow in the afternoon on a dry day, with a high setting and sharp clean mower blades. Mow slowly, no racing or sharp turns; everything is still 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 every week. Keeping the mower on a high cut through the first summer will help the roots get deep into the soil and thus reduce the amount of watering.