Hello, There is still a chance to get them to grow, and possibly even bloom for this next season. I've bought late season bulbs from Walmart in the past in February due to very good pricing this is what I did

I planted them in plastic cups ( 3 bulbs per cup) and I stuck them in the fridge for the remaining winter months. It does not necessarily have to be a fridge, but it has to be a cool and dark place that is above 32.F. The purpose of this is to allow the bulbs to get roots and what promotes that is these conditions. Then in spring, you can plant them in the ground, but I would at least give them 12 weeks in the fridge or cool place, that means if you planted them now, they should ok to plant in the ground the second week of April.

When I did this with my bulbs I had lots of blooms the following spring, but I did notice they were much later then local ones but they bloomed. One you plant them you should leave them in the ground to flower next year to gain strength.

Others may have different ideas but this is what I would do.

That would only make them flower for next Spring, then, and not this Spring (2011)? I was hoping I could get them to bloom for this Spring.

12 weeks in the fridge would mean I wouldn't put them in the ground until the end of April. We still get frost here in April, sometimes (I'm on LI).

A friend of mine told me to just plant them 6" deep on a day where I can work the soil (like, if we get a sudden warm spell with snow melting, the soil might loosen up enough), and that they should come up this Spring. But, since a couple of bulbs look like they might have some green at the tops, I was afraid it might kill them.

Actually that's what I meant, if you to this process, you should still get flowers this Spring (2011) they would probably just be a bit later then local spring flowers.

Planting them in mid April should be ok even with frosts, it is actually common for young Tulip sprouts to endure hard frosts in my region. Normally my Tulips and daffodils sprout not long after the snow melts. So you can image how much chances for frost they would see between then and their bloom time.

You could try your friends suggestion, but it could be weeks before the ground is workable, although I see some chances for warmth by the end of this week, the ground may not become workable, and if you get them in the soil too late, (I would say past February 10th in your region but guess) the less chance you will have for descent looking flowers this Spring. So my recommendation is sill for what I mentioned above.

Outfamily, you don't say where it is you live...if in a southern clime, then the bulbs would have been given a cool period by the grower or seller.
Actually your opening line brings up a question:
My mother bought some bulbs at Christmas.

What place, what nursery, would sell a bulb at the end of December in a northern clime. It would be then at the minimum, a month past their proper time to plant.
AT that time, if you had planted them they still stood a chance of coming to something. Here it is February...4 months past when they should have gone into the ground

Spring flowering bulbs cannot be planted in the spring...they have to be planted in the fall, when, with cooling temperature OF THE SOIl, they acquire roots.
With roots that form in the fall, it can stand up to winter's worst...temperatures down to 40 below zero. C or F
Without roots, they are at the mercy of the environment around them...freezing temperatures, worms, mice, squirrels and what you.
Without roots they cant form their stalk, their foliage, the bloom...they have not been fed to make that happen.

You have planted them into cold, cold ground...they wont acquire roots...its too cold. When the warmer temperatures of spring arrive they will begin to go mushy and then rot. They have to, they are no different than other things in the ground...they decmpose.
Sad to say, they should have gone into the ground when your mother gave them to you....and even at that time, chances are they wouldn't acquire roots...but hope springs eternal...better there than out of the ground.
Now, planted in February soil....they don't have a prayer.

I have a sneaky feeling you live in the south somewhere..hence the reason why they were available at XMAS. If they had gone into the ground at the time of purchase, then you could have looked forward to having a bulb garden. Planted as you did, into freezing ground....and of course, you watered them...ice crystals would have formed right away next to the tissue and begun their going mushy....and then rotting.
Its a sad state when a bulb is purchased the instructions of when to plant is not understood to be IMPORTANT enough to believe and left to wither on the vine.

If the bulbs are still firm, of course they can be planted now, if you plant them indoors. Put them into a pot indoors or into a forcing dish of any kind and put them in the sunlight. They will grow roots, they will flower, and when the last frost has passed you can replant them outdoors to recharge for next year.

Happy Day, the spring flowering bulbs, tulips and daffodils require a cooling period when they acquire their roots.
A tulip, for example, cant flower until the roots appear and from these they take in food.
You cant just plant a bulb into soil in February and think they'll bloom in April. There's a time itnerval of the cooling --14 to 16 weeks and, while this interval time can be shortened by placing into a refrigerator, the time of rooting is nonetheless required.

Sometimes we get away with not planting at the proper time because the soil temperature is not so far gone --up or down, that the bulb notices it. Thus, even in December a bulb can be planted in the ground....or forced indoors.
But sooner or later the soil temperature rises with the coming of spring. When that happens it tells the bulb to sprout. It has everything in it..the foliage, the stalk, the leaves, the bloom...all is inside the bulb ready to come out when the soil temp tells it to.
A bulb planted into COLD, COLD, ground will freeze its butt off. If it doesn't acquire roots, it cant take in moisture or food. Any moisture it does take in surrounding it, will freeze it and as soon as the soil temperature rises, it will turn to mush and begin to rot.

That is what is so thrilling about how a bulb, planted in the ground in the fall, acquires roots, it then is ready to sleep the winter away without ever being at risk from freezing temperatures. But, without roots, it doesn't have the protection--that's what is so magical about it.
Its alsmost like a caterpillar that turns to a beautiful butterfly--in nature it really is something to wonder about.

I have a similar question .... my neighbor just gave me about 250 daffidil bulbs that she did not get a chance to plant last fall due to illnesses in her family. Can I plant them now (in North AL)? Some of them already have little shoots on them. I believe she had them sitting in her garage. I hope I can make use of them!

Yes go ahead and plant them. They may not bloom this year but they will grow if they still are firm, not soft. Next year they will bloom at the normal time. Al