University of Illinois Extension - Selecting Trees for Your Home
http://www.urbanext.uiuc.edu/treeselector
Eastern Redbud
Cercis canadensis
Hardiness Zone: 5 - 8 
Mature Height: 20-30 Feet
Features: Bright, magenta pink flowers in spring, produced in large quantity; yellow fall color; mildly shaggy bark shows up well in winter.
Culture: Full sun to partial shade; moist, well-drained soil (trees in full sun may need more water); tolerates alkaline soils.
Cultivars:

Many, including

  • 'Alba'-has white flowers.
  • 'Northland Strain'-very cold-hardy, from Minnesota.
  • 'Silver Cloud'-leaves variegated with cream.
Mature Form: Rounded to broad spreading, often taking on a picturesque form.
Native To: United States (and Illinois)
Soil Conditions:
Dry
Soil condition: Moist, Well-DrainedMoist, Well-Drained
Wet
Tolerance:
Tolerance: Alkaline SoilAlkaline Soil
Dry Sites
Salt
Soil Compaction
Wet Sites
Tolerance: WindWind
Uses:
Barrier
Border
Foundation
Hedge
Use for: Massing.Massing
Naturalizing
Screen
Use for: Specimen.Specimen
Foliage Color: Green
 
Fall Foliage Color: Green
Yellow
 
Additional Notes: An understory tree, so fairly shade tolerant. Tends to be a relatively short-lived tree (25 years or so)