Three years ago we had a large raised bed made from railway sleepers.This year it's mainly been full of strawberries with some spinach and beans at one end.Recently I noticed a thick, bright white waxy substance on the granite chippings around the base of the bed .It almost looks like snow.Today I was horrified when tidying up the strawberries and loads of leaves on the bed to find loads of this growth in the soil under the strawberries, and caring the wood of the sleepers .I have pruned the strawberries and scraped as much of this growth off the soil and the wood as possible.It has a weird,almost sweet smell.Has anyone any ideas ?I should have taken a photo before I got rid of as much as possible and it got dark.Sorry !I'm going to email the landscaper who built the bed,part of which is going soft.But I would appreciate knowing if anyone else has had this problem,and wonder will I have to dispose of all my strawberries and soil.I hope not !Thanks.