The short growing season and cold temperatures of the mountains offer challenges to flowering shrubs as they must grow and produce flowers and seeds in a short time as well as survive a long cold winter. There are several beautiful flowering shrubs that can do well in these harsh conditions and provide color during the growing season. Two, lilac and mock orange, ae also known for the fragrance they add to the garden.
These five flowering shrubs are suitable for high altitude gardens up to 8,000 feet in USDA zone 3 or warmer.
Mock Orange (Philadelphus lewisii) ‘Cheyenne’
A native of North America, this spreading deciduous shrub has fragrant white flowers up to 2” across in early summer. The leaves are bright green and finely toothed.
Size: 6-8’ H x 5-8’ W
Light: Full sun to part shade
Soil: Average, moderately moist
Hardiness: Zones 3-6
Nanking Cherry (Prunus tomentosa)
This native of China, Japan, Korea, Tibet, Kashmir and the Himalayas is a dense, twiggy deciduous shrub. In early spring before the leaves appear white to light pink flowers 1/3” across are borne singly or in clusters of two. The fruits ripen to red and are attractive to birds. The dark green leaves are two to three inches long and covered with soft hairs.
Size: 6-10’ H x 6-10’w
Light: Full sun to part shade
Soil:Average, medium moist, well-drained
Hardiness: Zones 2-7
Bridal Wreath (Spirea x vanhouttei)
Native to North America, this decidous shrub is vase shaped with branches that arch to the ground. In early to mid spring small cup-shaped white flowers are profusely produced in clusters all over the bush. The dark green oval leaves have three lobes and are about 1.5 inches long.
Size: 5-8’ H x 7-12” W
Light: Full sun; tolerates some shade
Soil: Average, moderately moist, well-drained; drought tolerant when established
Hardiness: Zones 3-8
Common Lilac (Syringa vulagris)
An upright, suckering, deciduous shrub common lilac is native to southeastern Europe. In late spring it bears large conical to pyramidal clusters of small very fragrant flowers in various shades of magenta, purple and lavender as well as white. The oval to heart shaped leaves are three to five inches long and blue-green to gray-green.
Size: 8-15’ H x 6-12’ W
Light: Full sun
Soil: Average, medium moist, well-drained, neutral to alkaline
Hardiness: Zones 3-7
Snowball Viburnum (Viburnum opulus)
This native of Europe, northern Asia, and Africa is an upright and arching deciduous shrub. Large round clusters of white flowers in spring are followed by ¼” yellow fruits that ripen to red and are attractive to birds. The coarse round leaves have three lobes and may turn red in the fall.’Roseum’ is a sterile cultivar.
Size: 8-12’ H x 8-12’ W
Light: Full sun to part shade
Soil: Average, moderately moist, slightly acid
Hardiness: Zones 3-8