Heuver

Ash

Variety Description

Variety used for comparison: 'Patmore'

Summary: 'Heuver' is a seedless, green ash variety which produces symmetrical trees with a dense, rounded canopy, whereas the reference variety 'Patmore' has more irregularly shaped trees and a smaller angle between the branches and the trunk. The branches of 'Heuver' are significantly thicker and stronger than 'Patmore'. 'Patmore' grows longer into the fall, which makes the variety more susceptible to winter injury, while 'Heuver' is a more winter hardy variety. The bark of 'Heuver' is grey and smooth with few fissures, compared with 'Patmore' which has rougher bark that is grey with a bronze tinge. The leaflets of 'Patmore' are darker green, more glossy and more deeply serrated than those of 'Heuver'. The petiole of 'Patmore' is pubescent in the furrow, especially at the point of attachment of the basal leaflets, while 'Heuver' is a non-pubescent variety.

Description:

'Heuver' is a green ash variety which has an oval to rounded growth habit with a dense canopy and a very symmetrical branching structure. The branches are strong and form wide angles with the main trunk. The rate of growth is moderate. One year old shoots are light brown in colour and moderately thick, with no pubescence. In cross section the shoots are round. The vascular bundles at the leaf scar form an open 'C' shape. The bark of 'Heuver' is grey and smooth and the vegetative buds are medium to large sized, broadly ovate in shape and medium brown in colour. The buds are set above the leaf scar and are pubescent and valvate (no overlapping of scales).

The leaves of 'Heuver' are pinnately compound and the terminal leaflet is broadly elliptic in shape, with a broad cunneate base and acuminate apex. The leaflet margins are serrate. There is no pubescence on upper or lower leaflet blade surfaces but there is some sparse pubescence along the mid-rib on the lower surface. The upper side of the leaflet blade is moderately glossy and light to medium green in colour and the lower side is green with moderate to strong glaucosity. The petiole of 'Heuver' is shallowly furrowed with no wings and no pubescence.

'Heuver' is a dioecious variety which produces panicle type inflorescences on old wood just below new shoots. The calyx is present but there is no corolla. The flowers are small to medium in size and have no scent. 'Heuver' flowers early in the season. 'Heuver' ash produces no seeds.

Origin & Breeding History: 'Heuver' green ash was a selection from a group of seedlings which originated from a hardy seed source in Montana in the late 1970's. The green ash seed had been collected from a high elevation source in Montana that was subject to severe weather extremes. The seedlings were grown into large trees over several years at Foothills Nursery in Calgary, Alberta. In August 1987 several selections were made from these trees, based on growth habit, freedom from seed, winter hardiness, leaf glossiness and overall tree shape. Subsequent selections occurred with the final selection becoming the variety 'Heuver'.

Tests & Trials: Tests and trials for 'Heuver' were conducted at the Glenmore Farm of Foothills Nursery, Calgary, Alberta during 1999 and 2000. Fifteen trees of each variety were included in the trials. The spacing between the trees in each row was 3 metres and the rows were 3 metres apart. Measured characteristics were based on 40 measurements per variety.

Comparison tables for 'Heuver' with reference variety 'Patmore'

Length of terminal leaflet (cm)

Width of terminal leaflet (cm)

Length of petiole (cm)