Head Gardener's Blog: The Walled Garden Banks

The banks before and after treatment.

By late summer the banks in the walled garden were showing signs of stress, with bare patches and moss where grass had once been. This was down to a number of factors, but was exacerbated by Covid, meaning we missed our usual spring lawn treatments.

Before: The banks at their worst.

So at the beginning of September we as a gardening team set about trying to rectify these bald patches. The first part of this is to scarify the banks, nothing fancy here just a spring tine rake and a bit of muscle to scratch out the old thatch and moss. There is a large amount of thatch build up over the summer months as the only way to mow the banks is using a combination of a hover mower and strimmer. Both bits of kit that do not collect up the grass and therefore deposit it. Over time this cut grass builds up and becomes a layer of thatch that is detrimental to the grass. As this thatch robs the grass of the little amount of rain that we do have over the summer months.

Showing scarify and thatch raked out

Once this back-breaking job is achieved the banks look worse than ever with the bald patches even more prominent. Time to move onto the next job, moving topsoil so that a thin layer can be spread in the ever more balding patches, a process referred to as topdressing. This is vital for the seed that goes on top to be able to put its roots down into. 

 There is one issue with topdressing steep banks, that being gravity. All the soil wants to find its way to the bottom of the bank. For this reason very fine quality topsoil was purchased for this job as any large particles or clumps would only exacerbate this issue. Timing is also critical when it comes to this whole process as a heavy downpour would wash all the topdressing down the slopes. Fortunately the beginning of September was forecast to be dry with very little chance of rain.

 Once the topdressing is done, time for the seeding. The grass seed was also carefully chosen for this job. A mix of fescues was deemed preferable for the banks as they are more drought tolerant than ryegrass or other species of grass. Although there is one slight disadvantage to fescue over ryegrass and that is the germination is slower and can be slightly more sporadic. As speed of germination is critical, otherwise the topdressing would be washed away, we did come up with a method to shorten the germination time. That being 'chitting' the seed. This process involves soaking the grass seed in a bucket of water for a couple of days in a warm room. This allows the seed to imbibe water and start the germination process, in theory cutting as much as a week off the normal germination period.

 As the idea of the topsoil cascading down the banks before the seed had chance to germinate gave me nightmares (especially as this had happened last autumn). I explored options on how best to prevent this and found a product that effectively stuck the seed and topsoil to the bank. It contained a tackifer but also claimed to be a seed germination fertiliser and accelerator, which was an added bonus. Once applied to the bank and watered lightly the process was all finished.

The only thing left to do at this point was to continue to apply water to the banks, to try and keep the soil, and therefore the seed, from drying out. This proved to be some task in itself as September turned out to be a dry affair with little to no rain and plenty of sunshine. But, in fact, this worked to our advantage as this at least meant we could control the amount of water being applied to the banks.

 Hopefully the results speak for themselves.

Happy gardening!

Adam

Before and after: what a difference!