Are there other plants or bulbs which have roots which pull the bulb to the right level? Do daffodils do this?

Caroline, I am certainly no expert on bulbs but in my experience daffodils do not 'dig in' but can even come to the surface with a very little erosion over time. I love and grow various flowering bulbs and have had to deal with heaving and bulbs roots actually pushing the bulb out of the ground. I wish they all did the lily thing. lol

I do not get them coming to the surface,but occasionally the squirrels will dig a few.

I have found that my daffodils and tulips do "dig in" here. When I'm digging in sites where they've been planted before, I find them several inches deeper than what they had been planted.

Here's a link to a few Ohio natives with contractile roots. https://kb.osu.edu/dspace/bits...
Crocosmia is another plant. This link notes Narcissus and hyacinth and even contractile roots that move Muscari horizontally if planted at the right depth. Cool!
http://books.google.com/books?...

Very interesting! No wonder when we dig up a 'clump' of some bulbous plants we can't seem to get them all. They are under there sending some lower and even moving some out of the patch.

Most interesting!

Thanks for those refs.
That book on bulbs would be neat to have if it were not so expensive.