I'll start with the good advice and then give the backup plan :).
I dig mine right as soon as the leaves begin to show a little yellow, or 6 weeks after bloom. I lay them out to dry, come back in a few weeks, crumble off the dried roots and leaves and put them in mesh or paper bags until September for replanting.
The "other" plan is to replant them shortly after blooming while they're still growing. Dig up just like any other perennial, pull apart and replant. Works fine although the first method is preferred and the bulbs in theory should do better, especially for things like tulips and crocus which don't appreciate the root disturbance. Daffodils, hyacinths and snowdrops don't seem to care.

And yet another way of doing it, is to mark them with surveyor's tape, around bloom time. Just circle the foliage down at ground level and tie the tape. You can make notes on the tape too with black magic marker...cultivar name, or a description if the name isn't known, number of blooms the clump had this season, etc.
By circling them with tape, you can find and dig them much later, even if all signs of the foliage is gone. When you dig them, you can plant some back in the hole, and dry and store the rest as Kato described. They can then be planted in the fall, once the soil has started to cool down.

Here is a link that might be useful: Surveyor tape easily found in hardware or farm stores

Great advice and thanks for taking my question seriously. I'm sure a lot of people thought, "just do it, dummy!"

I don't understand the tape idea. Pictures?

Great advice and thanks for taking my question seriously. I'm sure a lot of people thought, "just do it, dummy!"
Seriously, it is a common problem that many of us often face. Life often gets in the way of being able to dig or move them at the ideal time of the year, which is while the foliage is still visible, yet has at least started to yellow.

I've even had very experienced daffodil growers tell me that they have moved them while 'in the green'. I've often found that the best time to do something, is maybe not the 'ideal' time for the plant, but what works for me and my gardening time.

I'll try to post some pics later of what I was trying to describe in the post above.

Sue

Cato B and ChemoCurl, thanks for your replies to the newbie ref: thinning of bulbs (daffies). I too am new to this website and just planted my first bulbs this past October. The daffies are up and not opened up yet and then it went to 19 degrees last night. Hope that doesn't kill them. Anyway, it's the experienced hands that can help us newbies along and it is greatly appreciated!

The daffies are up and not opened up yet and then it went to 19 degrees last night. Hope that doesn't kill them.
They should be just fine.

Anyway, it's the experienced hands that can help us newbies along and it is greatly appreciated!
But we too, were all newbies at one time.

I still haven't gotten a pic of the foliage marked with tape for digging later. Maybe tomorrow. I've come across a couple that I marked years ago, and still haven't gotten them dug. Maybe 2014 will be the year to finally get them done.

Sue

Several years ago, I set out to dig and divide my daffodils. Chemocurl was a great help to me in that process.

As the bulbs bloomed, I put plant markers right beside each clump with the name and/or description of the bloom written on it. (I use vinyl window shade slats, cut to size and marked with a sharpie.) It took a bit of discipline to keep up with it, but it was so worth it when it was time to dig.I also kept a list in my calendar of the order in which each variety bloomed in my yard. That was a great help when I was planning the re-plantings.

I marked my calendar for 8 weeks out once the bulbs bloomed (thus giving the foliage time to ripen, but not disappear), stuck the ID tags, and waited. Then I dug.

I sorted the bulbs by name and laid them on racks in my basement with the bulbs in a single layer to dry. I put the ID tags on each rack so I wouldn't get them confused.

I was able to lay them so that the foliage was all pointing in the same direction and the bulbs lay on top of the foliage of the row before them. I was able to get lots and lots of bulbs onto each rack, but still keep them all exposed to the air.

Then I just left them there for weeks. At some point, I needed the rack space, so at that point, I broke off the dried foliage, put the bulbs into onion and citrus bags I had been saving from the grocery and stored them WITH the ID tags.

Then I planted them that fall. It sounds like a terrible lot of work, and it kind of was, but by doing it in stages along the way, it wasn't so bad. I was thrilled with how many bulbs I got. I replanted the original area, plus another large area in my yard, PLUS a really large area at my church. It was worth the effort.

I just used string to mark mine. The circle left lying on the ground told me where to dig. I ID'd with a colored twist tie on the string. That's it. I don't have many kinds, though. I have one that is insanely prolific (Ice Follies, I think). So, for example, green twist tie for Ice Follies, white twist tie for pink daffodils.

A landscaper friend of mine gave me a bunch of these. I marked my big clumps while in bloom, then easily found them in fall to dig up, thin & transplant.

Here is a link that might be useful: link