Q.Planting Perennial bulbs in zone 6
I bought some allium bulbs at he Plant Show in Boston in March this year. I was told to store them in pots in a dark place in the cellar, spritz the soil occasionally to keep them from drying out. I did that. They are growing and are now about 6 inches tall! What do I do — plant them now or keep them in the cellar until the temperature rises?
Not sure what to do,
Zone 6 – Marlboough
Zella

Bring the allium up to a sunny window, preferably south facing. Water them but don't fertilize yet. There are many types of allium, some spring bloomers and some summer. If you have a summer blooming allium, I would not plant it out in the garden until after your frost free date. Otherwise, start the process of hardening them off so you can plant them soon. When they are in the garden and have started to grow, then you can fertilize them if you wish. Fertilizing too early doesn't give the plant the necessary time to establish a good root system so it can sustain new growth. Below are links to articles on hardening off and allium care.
https://www.gardeningknowhow.com/garden-how-to/propagation/seeds/how-to-harden-off-your-seedlings.htm
https://www.gardeningknowhow.com/ornamental/bulbs/allium/growing-alliums.htm
If your allium sends up a flower spike before you plant it, delay planting until after blooming is over.