Sorry, but Crinums won't survive in Zone 5b. Some species and hybrids, such as C. x powellii, C. bulbispermum & C. moorei, can be grown in Zone 6, with heavy mulch as protection, but Zone 7 is generally listed as the borderline for most of the one's grown in the South, those that are usually referred to as Milk & Wine Lilies.
You could grow them in pots and overwinter the bulbs indoors, in an area where temperatures are maintained above 20°F.
Rb

I suppose the best thing would be to leave them behind and find another showy bulb that will take Ohio winters. Any thoughts?

I suppose it depends on what they are, but surely bulbispermum will survive zone 6 here in PA no problem at all with no effort to mulch at all except perhaps 1 inch of cedar mulch to make the bed look nice.....C. variabile (a species as well) will survive zone 5 under mulch in Indiana as noted on Shield's Garden web site....mine are still relatively small so I have not put them in the ground yet. I have several hybrids along with many, many species in various size containers coming up the walkway and they do great for the summer....many, many bloom spikes despite being likely underpotted in most cases....in the winter they go in my garage (35F) and then back out for the spring......with some accommodation you can easily do this. If you can plant in a nice southern exposure right up against the foundation you will easily gain a zone so I say dig a few and give it a try.....either in pots or up against your foundation....best of luck with your move :o) Dan

i"d bring a few and try them like bluebonsi suggests.
a showy summer bulb used in ohio is lycoris squamigera.
good luck.

diggerb

I've had various crinum in pots including the lovely 'Splendens' in zone 5a the last few years. They wintered in a dim basement or in a warm sunny S. window. They survived and seem to be in about the same condition wintered either way. The foliage, now in the sun, shows sunburn and some of the leaves are bent in the wind. You can see them in one of my photo albums at photobucket. Perhaps the June album. You can find the link on my member page.

A nice suggestion- Allium globemaster for now
Orienpet lilium bulbs like 'Altari' or 'Conca d' or' for June- July

Karen