Most folks grow shallots and garlic to eat the bulbs, which makes propagation tricky at best :-) But if you have more than you need, yes, they can be grown from the extra bulbs. The ideal time to plant both is in fall, not long after the current season's crop is harvested. I'd pull the bulbs you want to replant, allow them to dry and the foliage yellow and ripen and then replant ASAP.

Hi, Gardengal48! Thanks. We had wanted to plant extra bulbs for this reason. :-) BTW, we know that these should all be planted in the fall but is it too late to plant some now?