Forgot to mention, we have a garage that stays about 40 degrees. Would that be an option to slow bloom development?

The hyacinth are at a point of showing what color they will be, pink or lilac and I am wondering if they are going a little too fast and will be spent by the April 17.
They will probably be fine. What I would do with them, is let them mature a good bit until they are nearly in full bloom. Then put them in the garage and dark would be best.
That should 'hold' them at that point for several days. They should then be very pretty and fragrant for the 17th and not immediately decline.

I know your bulbs are potted but below is a pic of 4 daffodil blooms after they been picked and stored in the cool dark basement for 5 1/2 days. I was really surprised at how well the blooms stayed nice after being cut that long.

{{gwi:11721}}

hth. Good luck!

Sue

Thanks for answering so soon, Sue. I will take them out of the cool, no sun room and put them back in the sun and grow light room until they are in bloom. Then to the garage. Your daffodils really did stay beautiful by keeping them that way.
I now do see that the white tulips are starting to show maybe some color, or at least a real bud. I may be keeping them too warm as they are under lights or else in bright windows because I want them to hurry up. I can see the white tulips are already getting a bit leggy, probably from being so warm. Daffodils are still nice and compact but no sign of blooming. It is going to be an adventure. Thanks again for answering.
Sherry