Spring sowing: timing and deadlines
We are often asked to advise on the best time to sow wild flower seed, and what is the latest time in spring you can sow and still expect results?
In practice this is quite difficult to predict as so much depends on the particular pattern of weather that develops each spring. Seeds need both warmth and moisture to germinate and grow. These conditions are most often met during March and April but can vary depending on season, soil type and location.
Early spring sowing is recommended wherever practical. How early you can start sowing will depend on workability of your soil. Light free draining soils are often ready from early March. Cold wet clay soils may not be suitable until April.
Experience shows that sowing hardy wild flower seed early in spring is a safe option in most years. Good results can usually be obtained if you sow whilst soil conditions allow with the expectation of better weather to follow. Wild flower seed is quite resilient and can last for weeks or months in the soil. Seed sitting in the soil will wait and germinate at the first opportunity given seasonal warmer weather combined with April showers. Many wild species are actually ‘primed' to germinate if exposed to a spell of cold weather after sowing; they can germinate more freely when the soil warms than seed sown directly into a warm seedbed.
Later spring sowing can also be successful if the weather is kind, but may carry a higher risk of problems if drought follows.
- Cornfield Annuals do need to be sown by the end of April to have enough growing time to produce a good display of flowers. Annuals sown in early May can work provided they have ideal growing conditions and get off to a quick start.
- Meadow and grassland mixtures are composed of perennial species and can be established at any time of year when there is sufficient moisture and warmth. Spring seed sown in the open before the end of April is successful in most years as there is usually enough rainfall for seedlings to establish ahead of summer. Sowing of meadow and grassland mixtures can be successful in May or even June if followed by a spell of good rain. Seed sown in May to July will often establish well in wetter western regions. Late spring and summer sowing is however more risky on drought prone sites in drier regions; unless the forecast for rain is particularly promising it may be safer to postpone sowing here until Autumn.
Posted on 10 April 2015,