Blueberries aren't ripening
There has been loads of fruit on my blueberry plant for about 6 weeks now but they're still all a pale blue colour. Some of them have started to shrivel and fall off. The bush is in a pot of ericaceous peat-free compost in a south-facing border. Could the wrong type of fertiliser be causing this? I've been using tomato feed just out of habit but now I'm wondering if this could be the problem. If so, is there any way to get them to ripen?