My hanging baskets are looking really pathetic currently, and the potting mix looks pretty sad. I want to really boost them, e.g. with some kind of rich manure-based supplement, but will that increase flowering or decrease it due to nitrogen??
I don't want to use chemical fertilizers because they will just get washed through with the next rain, and they certainly won't help to revitalise the dead-looking potting mix. I also don't want to re-pot 12 baskets every 6 months for the rest of my life...
So, what's a good way to keep the soil in hanging baskets rich and productive over the long term, that will promote lots of flowers and not just green leaves?