By Plantlove
United States 
I have two Flamboyant tree seedlings I have sprouted indoors. The tallest is about 4 inches. I currently leave the fluorescent light on them about 18 hours a day. When can I leave them without the light and place them near a window? When will it be time to take them outside? I live in zone 9 in california. Help Please!
20 Sep, 2017
I would start hardening them off now, gradually exposing them to more and more hours of sun and wind. The goal is to plant them in #5 containers, and keep them in a sunny part of the garden over the winter. Keeping them in pots is so you can whisk them under shelter when frost threatens the first winter. Once frost is past in spring, you can plant them out in a sunny, sheltered spot, and be ready for frost control in the winter.
All of this advice is based on the assumption that you are gardening in USDA zone 9 in southern California. If you live in northern California, USDA zone 9 is too close to the coast for enough heat to develop in summer for blooming. If you are talking about Sunset zone 9, you may have too much trouble with frost, as well as lack of heat.
20 Sep, 2017