With the UK doing a good impression of turning into Water World, I thought it might be a good time to write a post on our efforts to find trees that can cope with waterlogged soil. During the recent storms, a low-lying patch in our orchard flooded – again. It’s just a giant puddle, really, but it takes a few days at the very least to soak away. We don’t really want to put in expensive land drains, as the water does go after a while. So, rather than do battle with the bog, we thought we’d just try to plant things there that don’t mind about wet feet.
Most trees can take a brief bit of flooding, but a prolonged spell under water can deprive the roots of oxygen, eventually suffocating the plant. However, there are a few hardy souls that will grow, even thrive, in such temporary wetlands. Unsurprisingly, trees such as alder and willow, that are naturally at home along river banks, do well in the wet. So far, we’ve planted a Common Alder (Alnus Glutinosa) and a Violet Willow (Salix Daphnoides). After one winter, both seem totally happy.
For a more extreme water test, what I think are Goat Willows (Salix Caprea) are growing happily in our seasonal pond. Their trunks are submerged in about 2 feet of water for several months every winter, before the pond dries up again in the summer.
As well as putting up with the water, the alders and willows have lots to offer. They grow fast, can be coppiced for firewood, and both have pretty catkins that provide early food for bees. In permaculture terms, that’s a lot of useful yields…
If you’re after a more ornamental garden tree that can cope with the wet, the RHS has a list. Failing that, trees can be planted with their roots raised up on a slight mound of soil, to keep them above the worst of the waterlogging. We’ve done this with a pear tree that is a bit near the Puddle of Doom, and so far it appears to be working. The RHS also advise forking through the base and sides of the planting hole in wet areas, to stop water filling it up like a bucket, drowning a newly-planted tree before it can get going.
If you have any other trips on trees – or other plants – that can tolerate a bit of time under water, I’d love to hear.