Cotoneaster acutifolius Seeds | Peking Cotoneaster
LATIN NAME: Cotoneaster acutifolius
COMMON NAME: Peking Cotoneaster, Acute-leaf Cotoneaster
Plant Profile
Cotoneaster acutifolius is a deciduous shrub of the hills of northern and central China, growing on dry slopes, in thin scrub and on rocky ground, often over limestone. It makes a loose upright bush a metre or two high, with slender arching branches that layer where they touch bare soil, and leaves ovate to narrowly ovate with a wedge-shaped base and a drawn-out sharp tip. It reached European gardens through the French missionary-botanists who worked the Chinese interior.
The underside of the blade carries a soft grey felt of branched trichomes, many of them T-shaped, with a short stalk and a long cross-piece thickened at the wall. Their density changes with light, leaf age and shoot vigour, which is why cotoneasters are awkward to key out: a shaded leaf from a strong shoot can look like another species. Here the felt is thin enough for the blade to read green rather than white.
Small white five-petalled flowers, pink-flushed, open in short clusters on spurs along the previous season’s wood, and bees work them heavily. What follows is a pome, an apple in miniature: dry mealy flesh around two, occasionally three, hard smooth stones, each with one seed. Black colour comes only at full ripeness. Thrushes pass the stones intact, so seedlings appear under a fence line.
On a rockery, plant it where the arching branches fall over a stone lip; on a bank, group it so the roots bind the surface soil. Full sun gives the best autumn colour and the heaviest crop of pomes. Deer browse the young shoots in hard weather, and the spore bodies of Gymnosporangium rusts, whose other host is a juniper, can mark the leaves.
Science & Biotechnology
The genus has no great pharmaceutical tradition; its laboratory interest lies in the chemistry of the leaf, in the multiplication of selected plants in vitro, and in disease behaviour that interests fruit breeders.
Plants of the apple alliance move their photosynthate as sorbitol, not sucrose, and cotoneaster leaves carry the sugar alcohol with the phenolic acids that go with that metabolism. Leaf extracts are dominated by hydroxycinnamic acids, chlorogenic acid above all, with caffeic and p-coumaric acids, and by flavonol glycosides built on quercetin and kaempferol. The same leaf builds the anthocyanins that turn the bush crimson in autumn.
A nodal explant carrying one axillary bud will break and proliferate on a medium supplied with a cytokinin such as benzyladenine, and the shoots root readily after a dip in indolebutyric acid, so a chosen clone can be built up without the stone-by-stone lottery of seedlings. The genus also appears in surveys of fire blight hosts: Erwinia amylovora can live in cotoneaster tissue with little visible damage.
Uses & Benefits
The shrub earns its keep three times over: as a small hedge, as a subject for a rockery or a dry bank, and as a larder for birds in the lean months.
Set young plants 40 to 50 cm apart in a line and shear once or twice a season; they take hard cutting and can be kept to a little over a metre. The trade-off is berries: a hedge trimmed after flowering loses that season’s fruit, so where the pomes matter, shear in late winter instead and accept a looser outline.
Growing from Seed
Seed is easy to handle once the fruit has been cleaned, and the seedlings grow away quickly in their first season.
Mash ripe pomes in water, let the flesh float away and dry the stones on paper. The stones carry a hard coat and a dormant embryo, so they want a cold, moist spell before they will sprout: mix them with damp vermiculite in a sealed bag and leave it in a cold frame through the winter, then sow in spring, 5 to 8 mm deep in gritty compost.
The seed leaves are followed by the first true leaves, already recognisable by their grey undersides. Prick the seedlings into individual pots as soon as the second true leaf has opened, water from below, and stand them outside from their second spring. Pot on as the roots fill each pot, then plant out at 20 to 25 cm.
Our Take
I would plant the acute-leaved cotoneaster for the black fruit alone and keep it for the autumn leaves, low enough for backlit pomes to be seen against a hedge line. For a bigger, glossier foliage shrub on a windbreak rather than a rockery edge, the Peking cotoneaster is a different plant entirely. The pink crab apples of a Siberian crab apple make a fine autumn pairing across a boundary, and both sit well in front of an early lilac or a trimmed Japanese barberry.
Related Reading
More species in the same orbit as Peking Cotoneaster: