‘Don’t be too eager to cut back perennials’
Perhaps surprisingly, spring is an important time in a late-summer perennial garden. Some Millennium Garden plants are real thugs and if we don’t thin them in spring we’ll lose others later, as they tend to dominate once they grow. We can’t get in to tend the border in summer because everything’s so densely packed, so perennial weeds, such as ground elder and bindweed, must be ripped out early on.
Develop your planting scheme with different species and varieties that give a similar feel. While we’ve expanded the Millennium Garden and experimented with many new perennials that have come on the market since the garden was first designed, we’ve always kept Piet Oudolf’s original masterpiece firmly in mind. Not every year is the same in a garden. North Norfolk had a very dry winter and spring, then a very hot period and now summer’s here with a lot of rain. We adopt the ‘Chelsea chop’ and cut some perennials back at the end of May but they didn’t produce as much growth as usual, so are considerably shorter this year. We can’t change the seasons, so we just try and enhance the environment by adjusting the shade cast from trees and other planting.
It’s never too early to plan for next year. It’s always more cost effective and satisfying to produce your own plants from seed, cuttings or division – many perennials bulk up quickly and can easily be split. Pensthorpe is a 700-acre nature reserve so we always need a good stock of back-up plants because birds will destroy them.
Don’t be too eager to cut back your perennials because the garden can be spectacular in winter with frost hanging on the seed heads, golden grasses and mist in the air. It’s also a huge benefit for wildlife as well. Leave it until early spring.