Chester Thornless Blackberry

Rubus fruticosus ‘Chester’

In general, Rubus fructicosus is a semi-erect, scrambling, perennial, deciduous shrub with entangling and arching stem growth. The shrub typically grows in woodland threshold sunny edges, dappled in shade and is typically thorny with varying degrees of fruit production and disease resistance. The shrub is believed to have its origin in Armenia, and is now distributed throughout Europe, Asia, Oceania and North and South America. The ‘Chester’ cultivar was developed and later introduced in 1985 through a joint effort by breeding programs in Illinois, Ohio, and Maryland. The variety was named for University of Illinois fruit researcher, Dr. Chester Zych. The cultivar is a thornless variety that reliably produces large, firm blackberries of excellent eating quality that mature throughout the summer. Like the species, the variety is self-pollinating and typically performs best when staked or grown on a trellis for additional support. Although the flowers are attractive and the leaves retain attractive fall foliage, this blackberry is grown primarily as a food crop and it not considered appropriate for ornamental use. The shrub easily/annoyingly roots wherever canes droop or touch the ground. Shrubs are perennial, but canes are biennial – meaning berries will be produced only on second year growth or older (generative canes). For established shrubs, we recommend tip-pruning new vegetative canes (non-fruiting <1 year) in summer. Immediately after fruit harvest, remove all generative canes that fruited to the ground. In late winter to early spring, remove any canes damaged by winter and thin the remaining canes to 4 or 5 strong, well-spaced canes plus trim the laterals thereof.