Q.Hello-I Planted Tulip Bulbs In Pots In The Fall, And I Didn’t Know To Fertilize Them At That Time. I’m Trying To Figure Out I
f I can, and how much fertilizer I should use, now that they’re starting to grow. I have Bulb Tone food. They have started growing now, quite a bit, and we will still have frost and snow, so I’m not sure if I should leave them in the garage, or take them out when we do have nice days but put them back in the garage if it gets very cold out. They are very big to be moving them back and forth. Can they survive? Also, regarding my above fertilizing question, I have about 20 bulbs in 20” containers.

Certified GKH Gardening Expert
You are in hardiness zone 6 and tulips are generally hardy to zone 4. As long as there is no bud or bloom they can stay outside. If they bud or bloom and a freeze is expected, you can move them into the garage, cover them, or cut the blooms/buds and enjoy them in a vase.
It's too late to fertilize now. Most people in your zone 6 treat tulips as an annual, so if you plant again in the fall, you can fertilize.
https://www.gardeningknowhow.com/ornamental/bulbs/tulips/fertilizing-tulips.htm
https://www.gardeningknowhow.com/ornamental/bulbs/tulips/tulips-care-and-tulip-planting-tips.htm