Seattle Public Utilities’ policies/schedule regarding Christmas-tree disposal:

Customers can compost trees and holiday greens for free from December 26 – January 31! Remove all decorations, cut into sections 4-foot or less, and place trees or bundled greens next to your Food & Yard Waste cart on your regular collection day. Apartment residents may place up to two trees next to each Food & Yard waste cart at no charge. You can also drop off up to 3 trees less than 8 feet in length at a Transfer Station.

And also, a reminder that the “regular collection day” is disrupted for some again this week:

No change for Monday, Tuesday, Wednesday pickup customers, but no collection on Thursday, so Thursday customers will get pickup on Friday, Friday customers will get pickup on Saturday. The transfer stations are closed on New Year’s Day too. So bottom line, you have until the end of January for free tree disposal – but if your tree is drying out, better to avoid fire risk by not letting it stay until it’s unsafe.