Jason wrote in the comments: “Now that you mention fall coming, it reminds me that I need to dig up and divide alot of bulbs. Do you have some recommendations for when to divide and a good method for keeping track of them?” According to Brent and Becky Heath, the best time to dig up daffodils is right before the foliage dies back completely. Then you either replant immediately or store in a cool, dry place until fall, when you replant. This is the only method that works for me, because otherwise I can never find them. I know other people have moved them before and after they have bloomed, without harm to the plants. If you can find them, I think it is okay to dig them up and replant them in early fall. I’ve been told, “Fall is the time they start putting out roots, so you want to dig them up before the roots form.” However, every time I have dug up a bulb by accident, whether summer or fall, it has always had roots on it, so I don’t know if the “experts” know what they’re talking about or not.
As far as keeping track of them goes, I think you mean keep track of them in the ground. I really don’t try to. I usually only move my perennials around in spring, since fall is so short for us, and I know where they are then because I can still see them. Some people put short stakes in the ground all around the clump of bulbs. Others recommend planting grape hyacinths around them, because grape hyacinths put up foliage in the fall as well as the spring. Other people say don’t plant daffodils in your perennial garden. I can’t be that kind of a segregationist, myself.
So, for me, it’s either late spring/early summer, or not at all. And there’s so much else that needs doing then, it’s hard to find time for it. I can’t tell you anything about tulips because they’ve never flourished for me long enough to need dividing.