Bulbs for Naturalizing

Hello! I would like to plant large drifts of spring blooming bulbs on our backyard hill, and I have noticed in some bulb catalogs they sell 'Bulbs for Naturalizing' - usually daffodils. I was planning on mixing daffodils with other bulbs because we have a yellow house, so I thought all-daffodils would be a little too much yellow. =) But I'm not sure which other bulbs would be 'tough enough' to natualize an area on our rocky clay hill. Does anyone have any suggestions?

Blue or purple would be a nice contrast, perhaps Grape Hyacinths (Muscari), Siberian Squills, or Chionodoxa. They all naturalize well.

Oh yes, the blue and yellow would be gorgeous - I especially like the chionodoxa. I'm not sure what the Siberian Squill are - I will have to look that one up!

I assume the reason why they mark some bulbs as "good for naturalizing" is that some, like most tulips, don't come back reliably year after year. I agree with gemini, and the squill is one of my favorites. Here's a photo from a neighbor's yard, I haven't been able to get mine to fill in as nicely

ericabelle species tulips will naturalize in your zone for sure and ditto to what gemini sage said.

Sorry so late in responding - I didn't realize I hadn't been on DG for a while! I would love to grow tulips, but the squirrels and chipmunks think they are candy. I am going to try to plant some among the daffodils or the aliums in my flower beds - bulbs they don't eat. We recently planted daffodils, grape hyacinths, and spanish bluebells for naturalizing in the woods/yard. We had to put chicken wire over the ground to keep the squirrels from digging them up - they don't eat those, but they just dig them up for fun. It's hard to get mad at them, they are so cute!