Q.What Time Of Year Is Best To Transplant A Pineapple Lily?
It has been with me about 5 years and finally bloomed.
Certified GKH Gardening Expert
If you do so, you will need to dig it up every year. It is not hardy in your area. I would recommend keeping this one in container.
Should you choose to transplant it outdoors, You will need to do so after all chances of frost are gone. You will need to dig it back up after the first frost kills the foliage back in autumn.
This article will give you more information on the plant's care:
https://www.gardeningknowhow.com/ornamental/bulbs/pineapple-lily/growing-pineapple-lilies.htm