There are several hundred species of haws (Crataegus sp.) growing in the United States. Five are fairly common to Iowa: downy hawthorn, cockspur, pearhaw, punctate haw, and red haw. The dotted hawthorn is found in the eastern part of the state. It is extremely difficult to distinguish between the species.
Hardiness: Zones 4 through 7
Growth Rate: Slow to Moderate
Mature Shape: Small tree with wide, spreading branches and a round crown.
Height: Varies with species, most maturing between 10 to 30 feet tall.
Width: Varies with species, usually nearly equal to height.
Site Requirements: Hawthorns should be planted in full sun to part shade with moist, well-drained soils.
Leaves: Alternate, simple, with horns or spines
Flowering Dates: April - June
Seed Dispersal Dates: Fall - Winter
Seed Bearing Age: 4 years
Seed Bearing Frequency: Yearly
Seed Stratification: Prechill for 4-6 months at 36°F to 50°F
Found generally throughout Iowa except in the northwest section, this short tree, with thin, erect branching and a narrow, open crown, prefers the banks of streams and open hillsides.
The small leaves are narrowed or tapered at the base. The tips are round pointed and coarsely toothed, and the base is nearly smooth. The slender twigs are at first orange-green and smooth, later becoming bright chestnut brown and shiny. The older branches are ashy or reddish gray, with slightly curved spines of chestnut brown color, 3/4 to 1-1/2 inches long.
The fruit occurs in few-fruited, small drooping clusters. It is dark red or rusty orange in color with occasional dark dots and two or three seeds. On the trunk the bark is gray to dark gray-brown and breaks into narrow, flat ridges.