DH has recently put a lot of plants in pots around the garden, which look lovely. The only thing is, he's not an experienced gardener (nor am I), and he didn't realise he needed to think about drainage, so now some of the pots are holding a lot of excess water. Is there any way to fix this without having to take everything out of their pots? They range in size and it would be a faff to do it with some of the bigger ones...