Christmas trees normally go on sale during the later part of September and early October. Christmas items are known to go on sale before Halloween and Thanksgiving.
There are many companies and websites that offer coat trees for sale. Some of these companies that offer coat trees are Pottery Barn, Ikea and Bed Bath & Beyond.
Christmas trees sales are so that people can buy cheap Christmas trees in the run-up to Christmas day. The trees sold in these sales are often cheaper than what you might find in your average shop.
The Ikea store regularly has huge sales. One can easily find out the date of the next sale on the official Ikea website or on the official Ikea Facebook page.
Garden centres can be a great place to go and find Christmas trees on sale. They come in various sizes, so you can get them big or even small to suit the space that you have for one in your home.
Ikea stores sell furniture and household goods. They do not sell trees for your yard.
July
According to IKEAFanscom where I always go for my ikea sale information (most accurate, plus real people including ikea employees give the details), the next sale is on now! Until November 11th. http://www.ikeafans.com/home/ikea-us-kitchen-sale-20-off-free-financing-for-24-months/ Get free financing too.
Yes, Ikea has a large selection of leather sofas, armchairs and loveseats on sale. You can browse their site to find what you like. They are for sale, but not necessarily on sale. The prices however are still very affordable.
The internet would be the best place to buy an aluminum Christmas tree. Stores such as Sears or The Bay might carry these types of trees during the holiday season if there is a demand.
Ikea. That's where.
Christmas trees are real trees.