Can I get that on sale?

Appliances
You'll find specials year-round, but especially in May, Jun, and July - peak moving and renovation times.
Furniture
January which is usually a slow month for retailers
Lightning
January and July sales tend to coincide with stores' main buying times
Garden Furniture
August and September. Markdowns start in early August and gradually increase through September.
Perennials and trees
After Labour Day. Bonus, its actually better to plant perennials in September than in the extreme heat of July and August.
Sheets and Towels
January and August. Beware though, it can be difficult to find matching sets on sale.
Mattresses
Year round. Bargins can pop up at any time the year so you have to watch.
Pots, and Pans, China
Boxing week. Pre-Christmas warehouse sales, usually in November; also offer high-end selection.
Electronics
Prior to Super Bowl, Father's Day or Christmas. Sales tend to happen two and three weeks before major holidays and heightened male TV-viewing times.