I love growing them and have just planted out some more for tubs outside. I potted some up into a big tub by my kitchen door about two weeks ago and they're looking great. They had mildew though. First time that's happened!
I find them easy but I always start them off indoors. If yours are leggy then they are lacking light. Follow the packet instructions carefully and you should be fine. The winter flowering ones should be sown outdoors June-July, summer flowering ones sown indoors Feb-March or outdoors in May - July.
I don't sow direct into the lotty soil as they are a bit pricey to risk it so I do them indoors and then prick them out in modules for planting out when they're a bit bigger. I'd not sow them now personally as I'd prefer to wait til Feb, or later as I have no where to put them. Good luck