Diervilla Mill.

All three Diervilla species are native to eastern North America and are typically found as suckering shrubs growing in rocky habitats or open woodland where they are pollinated by insects such as bees and hawkmoths (Lance 2004). Although Diervilla have traditionally been significantly less popular in cultivation than the closely related and more showy Weigela, which is native to Asia, they are enjoying new popularity in North America and increasingly so in Europe as a group of tough, reliable small shrubs. They will grow in almost any soil and situation and are noted for their drought tolerance and minimal maintenance requirements, leading to their increased use in municipal planting schemes. They will flower all through summer; the display can be improved by spring pruning but this is by no means an essential annual task. Propagation is made easy by their suckering habit: suckers can be removed and re-planted or potted in the spring, or soft-wood cuttings can be taken in summer; treated with hormone and placed in a closed case rooting should occur within a few weeks. Diervilla are generally trouble free, but can suffer from leaf spot and powdery mildew. Besides their use in municipal plantings they are increasingly met with in gardens in the shrub border, as a small hedge, or in the woodland garden where they naturalise well (Hillier & Coombes 2002; Brickell 2003). In the UK a National Plant Collection of Diervilla is held at Sheffield Botanical Gardens, South Yorkshire.

Recent years have seen much breeding work to improve the range of Diervilla available and many new selections, such as the KODIAK^® Series cultivars, are being trialled and registered in the United States with new names appearing frequently. By the mid 2020s modern hybrid cultivars are probably more widely planted in gardens than typical forms of any species ever were. As Larry Hatch points out they have many virtues, and he notes that ‘the best variegated, bronze-tipped, purple-leaved and compact clones of pure Diervilla give this genus a truly vivid future’ (Hatch 2017). The forms with colourful foliage are at their best when planted in a position that receives full sun for at least part of the day, but they will grow perfectly well in light shade and even in dry shade, too (Proven Winners 2025).

In the early 21st century some horticulturists have considered the potential of intergeneric crosses between Diervilla and Weigela, however it seems there are greater barriers to hybridity between these two genera than might have been imagined. To date, none of the few successful crosses have shown significant promise, except perhaps D. sessilifolia ‘Butterfly’ × Weigela florida, but living plants obtained from hybridisation were found to exhibit ‘low vigor and poor growth under greenhouse and field conditions’ (Touchell et al. 2006) and we are not aware that any intergeneric hybrids have ever come to market.

Diervilla is named in honour of the French surgeon Marin Diereville who observed the genus during his visit to Canada in 1699–1700. On his return to France he introduced D. lonicera to European cultivation and the genus was later named after him. By 1739 it was being cultivated in England by Miller, though D. rivularis would not be introduced here until 1902 when material arrived at Kew (Bean 1981). The introduction of D. sessilifolia seems to have passed without obvious record, thought it must have arrived in Europe by the mid-19th century, for it was in European cultivation that the hybrid D. × splendens arose at about this time. Bean described D. lonicera as ‘the least ornamental of Diervillas’ and praised D. sessilifolia for being ‘much superior’ on account of the larger and more showy inflorescences, but this view perhaps fails to take into account their equally good foliar characteristics. Both have probably now been superseded by the various selections of D. × splendens. Bean advocated that plants ‘should be pruned back in spring before growth commences, when it will send up a dense mass of shoots that will blossom during the summer’ (Bean 1981).