Native blackhaw viburnum (Viburnum prunifolium) is only found in extreme south-west Iowa. There other more common hawthorns found in the state.
Hardiness: Zones 3 though 9
Growth Rate: Slow to Moderate
Mature Shape: Irregular
Height: 12 -15 feet
Width: 8 -10 feet
Site Requirements: Blackhaw viburnum prefers full sun to partial shade, with a wide range of soils, and is drought tolerant
Flowering Dates: April - June
Seed Dispersal Dates: Fall - Spring
Seed Bearing Age: 3-5 years
Seed Bearing Frequency: Yearly
Seed Stratification: Requires warm stratification followed by cold stratification. Sow seeds in the fall; they will not germinate until they have gone through two winters.