Pyracantha coccinea aka Firethorn

Pyracantha coccinea, or scarlet firethorn, belongs to the rose family. Its native range runs from southern Europe east to Iran. This woody shrub keeps its leaves in mild climates. In colder places, leaves may brown and fall through winter. Its stiff branches spread outward and carry sharp thorns. Garden plants often reach 8–13 feet [2.4–4 metres] tall. They can spread 12–13 feet [3.7–4 metres] wide. Some sources report plants reaching 18 feet [5.5 metres].

The smooth, reddish-brown bark has many small pores called lenticels. Young stems have fine hairs that disappear with age. The simple leaves grow in turn along each stem. They are dark green and glossy, with paler, hairy undersides. Their shape ranges from narrow ovals to spear-like forms. Small teeth or shallow scallops may edge the leaves. White flowers grow in close clusters on last year's wood. They bloom from late spring into early summer, often during May. Each flower has five petals and an unpleasant smell.

The orange-red fruit ripens in fall and may last into winter. It looks like a berry but is a pome. Birds eat the fruit and carry its seeds elsewhere. Many kinds of pollinators visit the flowers. Full sun gives the best fruit crop. The shrub also grows in part shade. It needs soil that drains well, without standing water. It accepts sand, loam, chalk, and clay across a broad pH range. Once settled, it withstands drought and hot, dry weather. Sources rate it for USDA zones 6–9 and UK H6. Cold winds and winter burn can still cause damage.

Its thorny growth suits hedges, screens, and boundary plantings. Groups can cover slopes and help hold soil in place. Gardeners can train it flat against walls or fences. Keep its sharp branches away from paths and play areas. Hard pruning after bloom reduces the fruit crop. Retain older flowering wood when shaping the shrub. Moving an established plant can be difficult. Deer tend to leave it alone.

Scab, fire blight, wilt, and honey fungus can affect it. Pests include aphids, lace bugs, scale, mites, and caterpillars. Birds may spread it into natural areas. Reports of invasive growth vary by place. PFAF records cooked fruit for jelly, marmalade, and sauces. RHS instead warns against people or pets eating the fruit. Treat it as ornamental fruit rather than a safe snack.