We have contacted the RHS and they offer the following advice to those who have had their plots flooded. We continue to be in contact with the Council and the Royal Parks to see what, if anything, can be done to prevent this happening again.
The RHS advises for the short term:
After flooding, wash down hard surfaces and collect up debris to prevent drains blocking, soil surfaces being covered, and pollutants or contaminants lingering in the garden. Wear gloves and overalls to minimise contact with pollutants.
Keep off the soil until it is workable, to avoid compacting it and worsening the conditions.
Remove damaged shoots from affected plants.
After flooding, edible crops near to harvest are best not eaten: no assurances can be given that root crops will be safe to eat, so they should be discarded. Plants eaten raw should be discarded too, and it is prudent to avoid growing salads and other uncooked crops for two years in case disease spores remain in the soil. However, the following year after flooding, it should be safe to grow crops that are to be cooked.
Apply a balanced fertiliser in the spring, mulching over the root area after application – any well rotted organic matter can be used here.
Foliar feeds during the growing season may help improve leaf colour, and encourage new root growth.
Water thoroughly in dry spells after a waterlogged period, as plants will be more susceptible to drought stress.
There is more information on the RHS website. Search for ‘waterlogging and flooding’.