It seemed an inevitable topic for this week, Living in the Derwent valley, thankfully on top of quite a hill I watched the waters rise on Friday from the average height of between 0.53 and 0.92m to an unprecedented 3.33m at its peak. Even though by Saturday afternoon the river was back within its boundaries the damage had been done and the ground that had been flooded was still saturated. It will continue to be so while we are still in the grip of wet weather. So I thought we had better look at what happens to plants when they are submerged in water. Is it the end? What should you do with wet soggy ground? and any preventions steps we can take for the future.
First things first, if your garden has been underwater or is just looking full of puddles and very squelchy. Get Off It. Stay away and look at it out of the window. When you walk on wet soil, It compacts the soil much more than walking on dry ground, this means, it changes the fine balance of particles in our soil. As with lots of things the space, silence and air are as important as the bits that are in between. When we walk on wet soil we squeeze the space between the particles out of the soil and squash together the soil particles . This will make it harder for roots, worms and water to move through the soil. This has a knock on effect on nutrient levels and microorganisms within the soil and the amount of oxygen available to plants and organisms that keep our soil healthy.
Plants can withstand being waterlogged for a short period of time.So don’t panic. However if the soil is permanently waterlogged plants have to resort to anaerobic respiration and this uses 19 times more of the plants energy to keep it breathing than aerobic respiration so your plants are going to use up their energy reserves pretty quickly
So once the puddles have disappeared and the ground feels drier you can get out there and get to work. If it was a temporary natural disaster that flooded your garden all you can probably do is loosen the ground by digging or forking it over, carefully around the roots of plants. this will get some air and space back into the soil and break up the compacted surface to allow any more rain to drain away easier. If you have discovered an area of your garden that is waterlogged just from rain not draining away there are various options to look into from digging in well rotted manure and grit to break up heavy soil. Raised beds can also be a good option to counteract the soggy soil. If the problem is more serious adding land drainage or a soak away may be your only options.
Getting back to work when you can. Don’t forget to keep dead heading your winter pots to keep them flowering.
Windrock, can also be an issue to contend with over the winter. Plants such as Buddleja, Roses, Salvia,Lavatera and Hibiscus can all be prone to being blown over in the wind. With the exception of the roses, the other plants on this list I would not prune until next spring. As they need the top growth to protect the plant from the winter weather however you can, shorten the top growth by 1/3, to make sure the plant is stable enough to make it through the winter. Especially if it is in an exposed spot. Roses, traditional rose beds were pruned hard back to about calf height in November to outward facing buds. these days we often grow roses in mixed borders and need to keep more height on the plants but my rose pruning has also changed since the cold winter of 2010. I tend to leave some growth on all roses in case of a bad winter and then have to gamble against late frosts when I prune them harder back in spring. It really is a lottery pruning and the weather as our temperatures can vary so much and the forecasts are so unreliable. The pruning itself, which people often find the scary bit it actually easy, make a good clean cut to an outward facing bud, cut sloping away from the bud. Judging the weather is the trick.
And so as the rain tips down again, always Tuesdays and Thursday at the minute. I wonder why? It feels cruel that we have problems with too much water while parts of Australia burn as they are so dry. If only we could get all of our floods down there. Anyway, Remember no walking on the garden, including turf, until it dries out a bit. You make lots of mess and do too much damage. Happy days, looking at the garden from the window! x