Advice on cost-effectively overseeding a tired sward

Overseeding can be an easier, cheaper, quicker way to rejuvenate a tired sward, but it will only be cost-effective if it leads to successful establishment.

This year’s waterlogged fields and cold soils could delay the opportunity to drill and, therefore, increase the odds of failure for many farms.

Despite cutting out ploughing and cultivation costs, overseeding still requires seed (even at lower rates), diesel and labour – and they are not cheap, points out Adas senior consultant Gillian Preece.

See also: Top tips on establishing tricky herbal leys

Having to repeat a failed overseed, or resort to a full reseed, will be an expensive operation.

“It is still a significant cost [to the farm] to do it properly, and you need to evaluate this against chances of success. It may be better to spend a bit more and do a full reseed,” she says.

Optimum conditions

Gillian says it is hard to make overseeding work well given the right circumstances, so unless this is the case, she would advise waiting until autumn to try for a more favourable outcome.

“Be ready for the right soil conditions and weather window on your farm – don’t be determined by calendar dates and don’t waste money by overseeding in non-perfect conditions,” she says.

Once ground improves, it is critical to walk the field.

Surface compaction issues caused by floods and waterlogging will need rectifying before any work begins, and Gillian suggests putting a spade in to check soil conditions first.

But timing a field assessment to is going to be crucial this spring, whether an older pasture or a more recently improved ley is earmarked for a spring overseed.

© Tim Scrivener

Flexible approach

“An open sward now could be very different by the time soil is suitable to work seed into.

“The sward might not be as open if weeds [have colonised it] or the existing grass has begun to grow. So assess fields at the time you are thinking about drilling – and prepare to be flexible,” she explains.

Although autumn offers less competition from grasses in the existing sward to newly emerging seedlings, an overseed still requires the correct conditions.

This includes sufficient rainfall to get seed establishment, says Gillian, adding that whether this takes place in spring or autumn, it is essential to get the basics right.