Spring has sprung! - when can we start sowing?

After a long gloomy winter in lockdown we have at last been blessed with some spring-like weather. Even more than usual people are keen to get outside and start moving on with their projects. As a result we are frequently being asked asked the question "how soon can we begin sowing wild flower seeds?"

March the 1st is the first day of meteorological spring!

Seeds need a combination of both warmth and moist soil (but not waterlogged ground) in which to germinate and grow.

These conditions are most often met sometime during March and April but the exact timing will vary depending on soil type, location, and the patterns of weather of that particular season.

Green roof sowing

Seed divided in two parts ready for sowing on chalky subsoil roof substrate

This winter has been particularly wet with record rain falling in most regions during February.  Most soils are too wet to cultivate and may take weeks to dry out enough to cultivate a seedbed.

How early you can start sowing will depend on character of your soil.

Light free draining soils warm up and dry more quickly, so are often ready from early March.  Where a soil is prone to drought later in summer, as for example on shallow green roof substrates, an early sowing can prove more reliable.

Cold wet clay soils are often difficult to cultivate to create a seedbed in early spring, and may not be dry enough or warm up enough to sow until April.

If you have ground preparation to do before sowing then you do need to allow enough time for this. If the soil is wet and unworkable you will need to delay until soil conditions improve to complete this and produce a good seed bed.

Where you can prepare a good seedbed in early spring sowing wild flower seed is a safe option in most years. Wild flowers are quite hardy, and should the weather turn cold for a spell the sowing will not come to any harm. Their seed is quite resilient; it can last for weeks or months in the soil and germinate at the next opportunity when conditions improve.  Many wild species are actually ‘primed' to germinate if exposed to a spell of cold weather after sowing then germinate more freely when the soil warms than seed sown directly into a warm seedbed.

Green roof seed mix

Mixing seed with larger volume of sawdust to aid spreading by hand

Posted on 01 March 2021,
Category: Advice