I had a chap in to clean and stain pour vast area of decking last summer, but new patches of mould etc. have now appeared. I have googled it and found various different methods for getting rid of this, but they all involve thoroughly rinsing the decking afterwards. I cannot do this without hosing the residue onto the flower beds, some of which lie below the decking. I cannot think that the bleach/soda crystals etc used to clean the decking will do the plants much good!
Any wise words to offer?
The main room in your house...


