when to feed the grass

When to Feed the Grass

Follow a few simple rules to apply your lawn fertiliser and get the best results from your grass whether it's a spring, summer or an autumn feed

A guide on how to effectively feed your grass at different times of the year and using various application methods

Conditions for Application

To be read in conjunction with the product label

Adequate Soil Moisture

This means as long as the the lawn is actively growing and the soil is moist. It may not have rained for a week and there may be no rain in the forecast but as long as there is adequate soil moisture present then it is safe to apply. Some fertilisers do need watering in if there is no rain and this will be noted on the label. If the soil is dry and hard consider holding off until adequately watered.

Apply Before or After Rain?

Always apply after rain for two excellent reasons:

  • You can check there has been sufficient rain as forecasts aren't 100% reliable
  • Heavy rain can wash out you fertiliser in the early days

Apply after Mowing

Always apply fertiliser straight after cutting the grass. This means it’s got maximum time to settle into the lawn before the next cut.

It is beneficial when using iron or liquid products to leave the box off for the first cut after application if your mower instructions allow.

Spring Lawn Feed

Being flexible and using a little common sense is the order of the day when using lawn care products. Plan to apply the spring fertiliser between March and May. March if you're in the south with April being the target for most people.

Don’t rush to apply. Let the grass tell you when which is generally when you start mowing regularly. Quite often in late winter or very early spring, you notice the grass finally starting to grow and so you give it a cut. It may be another 3 to 4 weeks before you mow again because it’s still cool and growth is slow. Once you get into a rhythm of regular mowing at least every 7-10 days (perhaps the fourth cut of spring) then is the time to feed.

Summer Lawn Feed

You will normally apply your summer fertiliser between 10 to 14 weeks after the spring treatment. If the weather is dry then withhold fertiliser. It is not going to start working without moisture and though Lawnsmith® Fertilisers have little scorch potential, the salt content can add to already stressful conditions. If conditions suddenly change half way through the summer you can then feed the grass with a granular or liquid fertiliser.

Autumn Lawn Feed

September or October are the target months for applying your autumn fertiliser. Once again national temperature and weather patterns apply, but as a rule wait until the rains start in late August or September, and then apply your lawn fertiliser. Dependent on where you live you’ll find some years this may mean early September and other years late October.

Autumn treatments also need some common sense timing. My cut off for fertilising in Yorkshire is the first week of November. If you start putting nitrogen in too late in the year you can bring on some disease (fusarium). Therefore mid November could be the cut-off for balmy Bognor but perhaps mid October for crisp Cumbernauld.

Winter Lawn Feed

If you’re adding Green-Up Ferrous Sulphate in winter then consider September as your starter month. You can re-apply up to April very safely. Remember though that this is more like a vitamin and not food so you can and should still fertilise as normal.

If you’re using an iron fertiliser such as WINTER GREEN High Iron then November onwards is best with a mild spell between December and January being optimal. Don't use it at the same time as Ferrous Sulphate though because Winter Green contains ferrous sulphate, and you'd be over doing it if both were added in the same few weeks.

CAUTION: Iron whether in pure sulphate or fertiliser form will blacken moss at high rates in most conditions. This is the reason moss killer is ferrous sulphate based. It can blacken grass at high rates in dry conditions therefore always apply in cool wet conditions.