Several of my customers want to buy a live potted spruce for Christmas, keep it inside for a short period of time, then plant it in the spring. So far the info on chilling requirements I've found indicates that Colorado spruce *may* have met it's chilling requirement by Christmas. I've found nothing for white spruce. Here's the dilemma: Chilling requirment met: Tree may be triggered into breaking dormancy by time inside. Put outside, all buds die. But, can keep inside in cool room by south window, and tree will have an extended summer. Chilling requirement not met: No reasonable amount of time inside will cause tree to break bud. Putting it outside if done gradually will re-acclimate to winter, then plant in spring. Anyone got a lead to more information about how dormancy works in P. glauca and P. pungens?
My normal reccomendation to clients for that issue (here in Burnaby BC, generally mild at Christmas) are: leave tree in cool spot as long as possible bring inside gradually if temps are drastically different between out and indoors. 'water' tree with 1 or 2 trays of ice cubes daily (keeps roots a bit cooler and helps keep water from just pouring off over the rootball) keep lights etc off as much as possible, keep room as cool as possible put back outside and plant as soon as possible, acclimatize to outdoor temps gradually if needed. keep fingers crossed The blue spruce is a good choice for survival chances, the harder needled spruces do better than softer needled firs in general.
