Rainbow Pillar Serviceberry Tree

Rainbow Pillar® is a narrow, upright serviceberry selected for a compact footprint, white spring flowers and orange-red fall foliage. It can serve as a specimen or a lightly repeated screen, though its final width varies with taxonomic treatment and training. ## Landscape use and seasonal interest Iowa State Extension lists ‘Rainbow Pillar’ with Canadian serviceberry and notes its upright habit; the Dawes Arboretum records it as ‘Glenn Form’ and reports the alternate name ‘Glenn’s Upright.’ Dawes also documents US Plant Patent PP 9,092, issued March 28, 1995. The patent citation is historical and does not establish current legal status. Minnesota Extension lists the cultivar at about 20 feet tall by 10 feet wide, with orange and red fall color. See [Iowa State Extension](https://yardandgarden.extension.iastate.edu/how-to/serviceberries), the [Dawes Arboretum record](https://dawesarb.arboretumexplorer.org/taxon-19964.aspx), and the [Minnesota guide](https://extension.umn.edu/garden-and-home/yard-and-garden/lawns-and-landscapes-in-minnesota/trees-and-shrubs/serviceberry). ## Identity and siting Cultivar references do not use a single taxonomic combination: Dawes lists *A. canadensis* ‘Glenn Form’ and gives *A. laevis* ‘Glenn’s Upright’ as a synonym, while other horticultural references place Rainbow Pillar among serviceberries more generally. Keep the narrow cultivar identity clear and confirm the supplied nursery label before changing its botanical classification. Serviceberries generally grow in full sun to part shade and moist, well-drained soil; spring flowers and berries support seasonal wildlife value. ## Maintenance Water while establishing and during prolonged dry periods. Prune selectively after flowering to maintain clearance and the desired narrow outline. Check the base for suckers and remove only those that would interfere with the intended tree form.