DRY SPRING SOWING UPDATE
This years’ early spring with pleasant warm dry weather has made it easy to get on with seedbed preparation. The record lack of spring rainfall however is not as welcome as it gives rise to worries with delayed germination of sown seed.
Fortunately wild flower seed is quite resilient and can last for weeks or months in the soil - it will germinate as soon as sufficient rain arrives.
Spring seed sowing in the open if completed before the end of April is usually successful as it is reasonable to assume that we will have enough rainfall at some point before summer. Sowings of meadow and grassland mixtures can be successful in May or even June if followed by a spell of good rain.
Rolling seedbeds in drier conditions can help improve seedling establishment.
Rolling will firm the seeds into contact with the soil and connect them by capillary action with moisture below the surface. Loose seedbeds by contrast are prone to dry out at the surface depriving surface sown seed of moisture.
Watering is perhaps an option for smaller sites. If you do decide to water make sure you water thoroughly and can keep watering through the dry spell until your seedlings are well established.
Irrigation is probably necessary for most green roof sowings in spring. The shallow depth of growing media used on most green roofs can only hold a limited amount of water and sowings on roofs are therefore more likely to experience drought conditions.
At Emorsgate we have just sown a new green roof demonstration trial which we gave a ceremonial topping off - watering with Adnams Ale!
Posted on 15 April 2011,