Fraxinus ornus aka Manna

Fraxinus ornus is known as flowering ash or manna ash. This deciduous tree belongs to the olive family, Oleaceae. Its native range spans east-central and southern Europe to the Caucasus. It also grows naturally in parts of western Asia. Garden trees reach 40–50 feet [12–15 m] in height. Their rounded crowns spread 25–50 feet [7.6–15.2 m] across. Trees in Europe can reach 75 feet [22.9 m]. Some trees form several upright trunks beneath a dense crown.

The bark stays smooth as the tree grows older. Its colour ranges from greenish brown to grey. Stout twigs carry hairy, grey-brown buds. Leaves grow in opposite pairs along the stems. Each pinnate leaf has five to nine leaflets. The leaflets have toothed edges and dark green upper surfaces. Their undersides are paler, with hairs along the veins. Leaves turn yellowish in autumn before they fall.

Fragrant white to cream flowers bloom from April to May. They appear with the leaves or shortly after them. The flowers form loose clusters called panicles at shoot tips. Each flower has four narrow petals. Winged fruits, called samaras, hang in clusters after flowering. They ripen from late summer into autumn, turning green to tan. Some fruit clusters stay on the tree through winter. Heavy seed crops can lead to many unwanted seedlings.

Grow flowering ash in full sun for best results. It favours deep, fertile soil that drains well. Moist loam rich in organic matter suits it well. It also grows in chalk, clay and sandy soils. Established trees tolerate some drought, and cool summers favour growth. Missouri Botanical Garden advises shelter from strong winds. Sources place its lower USDA hardiness limit at zone 5 or 6. The RHS gives it a UK rating of H5. Garden uses include shade, street, lawn, woodland and coastal planting. Its flowers add spring interest, and it attracts birds.

Pest reports differ: Oregon State suggests resistance to emerald ash borer. Missouri Botanical Garden warns of susceptibility and advises against new planting. Other reported problems include borers, flower gall mites and ash yellows. Honey fungus and ash dieback also merit attention. Cuts in the stems release a sweet substance called manna. People use it as a sweetener and mild laxative. Contact with the sap can cause local or wider allergic reactions. Its laxative use can also cause wind and pain.