USDA Growing Zones: 2 to 11, depending on cultivarSize: Depends on cultivarExposure: Full sun 

The western redbud can also attract hummingbirds.

USDA Growing Zones: 4 to 9Size: 20 to 30 feet tall and 25 to 35 feet wideExposure: Full sun-part shade

USDA Growing Zones: Varies by species, mostly in the warmer zones, with some as low as Zone 7.Size: Varies by speciesExposure: Full sun

Other species of Crataegus trees also attract hummingbirds.

USDA Growing Zones: 4-8Size: 15 to 25 feet tall and wideExposure: Full sun

Also consider Aesculus x carnea, which is a cross between a horse chestnut and red buckeye.

USDA Growing Zones: 4 through 7Size: 50 to 75 feet tall and 40 to 70 feet wideExposure: Full sun 

You could also grow Southern catalpa (Catalpa bignonioides) to attract hummingbirds.

USDA Growing Zones: 4 through 8Size: 40 to 70 feet tall and 20 to 40 feet wideExposure: Full sun 

USDA Growing Zones: 5 through 9Size: Can be a shrub or small tree. Usually 10 to 25 feet tall and wide, but can grow over 30’ tall sometimes.Exposure: Full sun, part shade

USDA Growing Zones: 6-9Size: 20 to 40 feet tall and wide, sometimes growing largerExposure: Full sun

USDA Growing Zones: 8 through 10Size: 8 to 30 feet tall and wide, depends on the varietyExposure: Full sun to partial shade 

USDA Growing Zones: 4 through 9Size: 80 to 100 feet tall and 40 feet wideExposure: Full to partial sun