USDA Hardiness Zone 4
RHS Hardiness Rating H6
One of the most commercially successful of the forsythia clones derived from Bolesław Suszka’s breeding work at the Kórnik Arboretum in Poland in the 1950s; its parentage is listed as F. × intermedia ‘Spectabilis’ × ovata (Arbofux 2021), though it is presumably the same as the plant appearing in Hatch’s Cultivars of Woody Plants as F. viridissima ‘Konarek’ (Hatch 2021–2022); ‘Kanárek’ is also given by Esveld as a clone of F. japonica, a very rare species in cultivation but one which was hybridised by Suszka (Esveld Nursery 2022; Suszka 1959).
‘Kanárek’ (‘canary’ in Polish) makes a compact shrub to 2 m tall, with rather small and deeply toothed leaves (in some online photos); its shoots rise rather stiffly but neatly and do not criss-cross in the typically tangled fashion of a mature forsythia; it is described as hardy and floriferous.
‘Kanárek’ is represented in the UK National Collection of forsythias at Sculpture by the Lakes in Dorset by two quite different plants. One, purchased from Larch Cottage Nursery, so far shows the compact habit and small, deeply toothed leaves shown in many photos of the plant in eastern Europe. (Larch Cottage’s own description of their plant as ‘variegated’ is certainly misleading). Another is a cutting taken from a plant grown as ‘Kanârek’ in the former National Collection at Pershore College, which was a vigorous, untidy plant with rather large leaves (M. Gudgeon pers. comm.). At least one Polish source does describe ‘Kanárek’ as large-leaved, so it seems likely that more than one clone is now circulating under this name.