I received this question about fertilisation after scarifying from a Mr. Pricket in September 2017 through my ask a question page.
I’ve been through the annual slog of scarifying and re-seeding the lawn. Slightly concerned as I really tucked into the thatch and left quite a lot of open space between plants. Once the seed takes I’ll fertilise, but I’m unsure as to what balance to go with. To get the new grass going I was going to use nitrogen heavy and then in October/November go for something more balanced to go through winter. Thoughts? I live in St Albans (Hertfordshire). First time I’ve really got into the thatch on my lawn and don’t want to ruin what is usually a lush surface!M. Prickett
Hi Mr. Prickett,
In the autumn you really don’t want to be applying any high-nitrogen fertiliser to your grass, even if you have overseeded it. The light is fading and you will artificially stimulate the grass to grow soft, weak leaves. Too much leaf growth in the darker winter months will leave the grass susceptible to fungal infections and frost damage.
Fertilisation after scarifying your grass
Grass seed doesn’t need any fertiliser in the first few weeks of growth. It has enough food in the seed shell to put up a leaf and make a root. The scarified grass will certainly benefit from feeding though as it will be stressed and try to recover damage.
I assume these works were carried out in early September. I would apply a slow release autumn feed with some added iron within 4 weeks after the treatment. This will toughen the grass up and enable it to grow a strong root system to support lush top growth in the spring. The iron would help to keep any moss ingress down and stimulate toughness in the grass.
Hope this is useful, thanks for reading.
The Lawn Man