Early bulbs, especially those planted with a southern exposure or close to a house, might sprout prematurely. The first greenery to show is foliage with flower buds emerging much later. Cold weather might damage the edges of the foliage, but unless the flower bud has appeared, it will not affect the future flowering or health of the bulb.
A few of the small early bulbs – winter aconite, snowdrops and glory-of-the-snow can tolerate a bit of frost.
Check garden beds to be sure plants have not heaved out of the ground due to freeze-thaw-freeze cycles. Gently press the crowns of perennials back into the ground; avoid compacting the soil by not stomping heavily around plants. Apply mulch to root zone and not over the crown of the plant; Moana recommends G&B Organic Soil Building Conditioner.