Don’t give up in despair if your garden is prone to flooding. Nature can work wonders and there’s much you can do to limit the damage.
Who could not feel desperately sorry for the poor souls sloshing around in December having been evacuated from their homes in eastern England and elsewhere. Obviously no-one is going to rush around protecting plants when several inches of filthy water is swirling around the kitchen but the effect on gardens can be utterly depressing.
My friend in South Wales arrived home one day to find her Belfast sink of lavender floating away down the garden and was astounded at the sheer force of the water flow.
“We lost all our pots,” she said. “Even those with large shrubs in them. And others lost whole sets of garden furniture so they should secure them firmly.” My friend said the worst of it was the sight of her garden covered in a layer of silt and the paths so disgusting they had to be pressure hosed. But her precious hosta collection and most of her herbaceous perennials lived to fight another day.
“The bonus is, if you’ve got a septic tank and it gets flooded, you end up with a very fertile garden,” she laughs.
Unlike trees and shrubs that can be destroyed by one flood alone, herbaceous perennials renew a large part of their root system annually and will recover once water levels recede. Most plants will survive a few days’ immersion in water but, like us, they need to breathe and if the roots are starved of oxygen they will die. So if your soil is waterlogged, especially with salt water, it’s best to gently lift the plants and heel them in elsewhere or in a pot with fresh compost.
For woody plants, keep an eye for signs of dieback, remove dead sections, prune into shape then give the plant a liquid feed and hope for the best.
Think about improving drainage, especially if you’re on clay which gets easily compacted. A couple of buckets of grit to every square metre will help. And plenty of organic matter to keep the soil open and friable.
Useful plants that will withstand a degree of water logging are hosts, dogwoods and that great stalwart Iris Siberica.
As a last resort, raised beds are not just for veg and can look amazing filled with your favourite ornamentals.