My son seeded his lawn 3 weeks ago. It is 60 ft x 60 ft. There was a good lawn before building work caused it to be flattened and neglected for months. The soil is clay based. We roto-tilled it, raked and leveled before adding yards of topsoil which looked sandy. A spreader was used to seed. Then there was torrential rain which moved some seed into hollows. It has been kept damp and most areas are shooting. It is patchy. My question is “what next?”. Should we keep it damp and leave it alone? Any advice would be very welcome. Thank you.
Thank you for contacting the Toronto Master Gardeners concerning your son’s newly seeded lawn.
In general, late summer to early fall (mid-August to mid-September) is the best time to establish a lawn from seed. During this time period, the soil temperature and soil moisture is optimal for germination. Sowing seed in mid September ensures that there is enough time for seed to become established before winter.
Newly seeded areas should be kept moist until the seed germinates and seedlings become established. Germination for grass seed varies anywhere from 5-30 days depending upon the variety. Germination can even take longer during cooler temperatures. Seeds can also be buried at different depths, especially after a torrential downpour, causing variation in germination. Therefore, it is important to keep the surface area constantly moist until all seeds have germinated. Until your planted area is showing signs of dense green growth, do not allow area to dry out. According to K-State Extension: “Once the seed is sown the upper surface of the soil should remain damp at all times. This may require daily, light applications. It all depends on the amount of sun and wind. Be prepared to water when needed as lack of water will slow establishment.“
In the spring, if areas still show signs of patchy growth you can reseed these areas. The best time to apply seed in the spring is when the temperature is no cooler than 15C. This will ensure that the soil temperature is warm enough to encourage germination.
OMAFRA ( Ontario Ministry of Agriculture, Food and Rural Affairs) has an excellent factsheet on Lawn Establishment. You may also be interested in Landscape Ontario’s factsheet on Sowing Grass Seed.
Two other articles which may be of use are: How to Maintain a Healthy Lawn and Get Your Lawn Ready for Spring
Good luck with the lawn.
Oct. 10,2022