What to do when my garden has been flooded?

What to do when my garden has been flooded?

The severe flooding experienced across Cumbria in 2015 left many Cumbrian gardens with heavily water logged soil and has led to the loss and damage of a number of trees, shrubs and perennials.

How do plants drown?

As the floods begin to subside, gardens which are poorly drained and in which the water is unable to drain away will become waterlogged, and unfortunately few garden plants are able to cope with long periods in ground saturated with water. The water fills all the air spaces between the soil particles preventing oxygen from reaching the roots, the soil stagnates and the roots are unable to grow.

Plants which have been underwater for anything like up to a week are not necessarily lost, but it is probably wise to take cuttings where possible. Roots of plants which seem to have survived may actually have been weakened or damaged and may die the following season so, if you can take cuttings then it is probably wise to do so…

Unfortunately it is shrubs and fruit trees that suffer most in waterlogged soil. Unable to put on new roots as quickly as perennials, shrubs cannot cope for long periods underwater.

How do I get air back into my compacted soil?

For any borders that have become particularly wet and compacted, the best way to help the soil aerate is to use your fork and gently ease the prongs in and then backout so lifting the soil rather than turning over. Do this every 6 inches or so, to let much needed air get back into the soil.

Do not eat any vegetables which could have become contaminated – unfortunately there is no solution to this other than to dig it up and make a flood compost pile – keep this pile away from your normal composter and then layer leaves, stems and debris with the mud brought in by the storm, give lots of time to rot down and then put it back onto your garden – At least something good can be put back into the garden after the damage.

How do I clean my plants after flooding?

Remove mud and other pollutants from your garden plants by – yes, watering! The good you will do in removing the pollution outweighs the damage of further saturating the soil and dilutes the concentration of any pollutants brought in by the flood water; they will be less harmful to the plants and natural recovery will be faster

Once the plants are cleaned (or as clean as possible) you will be able to see if any are actually broken and you will have a better idea of where pruning is needed.

Deal with major damage first – large trees and anything which looks dangerous needs to be removed before you can start on the smaller plants.  Prune any broken stems back to the next new shoot, but be aware that hard pruning after such extreme weather can add stress to plants already under pressure so, if you are not sure, just prune the bare minimum. You can always come back in a couple of weeks and see if anything else needs to be done.

Do I have to empty any pots which have been flooded?

Any pots still standing in your garden will have been able to drain out the excess water so saturation of the soil within is not so much of a problem. Do allow the soil to dry out before you start watering again and add in a good quality fertiliser to boost soil properties.

Most flooded gardens will recover fairly quickly and often once the water has receded the new soil which has been brought in by the floods will contain high levels of organic matter, so there is a silver lining to be found from the devastation.

Grass and Ground cover plants will need to have the majority of the soil which was washed in by the floods removed. Once the tips of the plants are showing rinse the remainder of the soil below the tops of the leaves and let nature do the rest!