These are hardy lily bulbs that don't like to be kept in storage too long so as long as your ground isn't frozen, you can safely plant them in well prepared soil. Make sure you have good drainage and an organic mulch on top will help keep the bulbs cool as they settle in before the sprout comes up!

I hope this helps!

Cheers,

Riz

New Jersey is zone 6 with some zone 7 along the coast. I'm not sure exactly what part of NJ you're from, but I'm up north almost in Sussex county and the rule of thumb I go with is not to plant anything until Mothers Day, it can be tempting to do planting before hand. But you're definately out of the danger of frost by that time.

I am with Riz here. By Mothers Day you will have shrivelled dehydrated Lily bulbs. Plant them ASAP. If you will have a hard frost pedicted, you will protect your Lilies in case they will have big sprouts at that time. There is absolutely no need to protect Lilies in the ground in your area.