Fraxinus ornus (flowering ash, manna ash)

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Fraxinus spp.

ashes

Oleaceae

Temperate Northern Hemisphere (North America, Europe, and Asia)

Attracts Butterflies Drought Tolerant

Native to North America

SunFull Sun – Part Shade

WaterMedium · drought-tolerant

HardinessZones 3–9

Overview

Fraxinus spp. is a genus of about 45 to 65 species of mostly deciduous trees in the Oleaceae family, spread across temperate and subtropical regions of the Northern Hemisphere. Trees reach 30-120 feet (9-37 m) tall with an upright trunk and a rounded to oval crown. Leaves are opposite and pinnately compound, 6-15 inches (15-38 cm) long, with 5-11 toothed leaflets that turn yellow or, in white ash (F. americana), purple to maroon in fall. Most species are wind-pollinated and many are dioecious, with male and female flowers on separate trees; the small flowers open in spring before or with the leaves. Female trees produce hanging clusters of single-winged seeds (samaras) that spin as they fall and can seed prolifically into open ground. Ash wood is hard, straight-grained, and shock-resistant, used for tool handles, furniture, and baseball bats. Across North America, the emerald ash borer (Agrilus planipennis) has killed tens of millions of native ash trees since 2002, and the threat limits new planting in affected regions. The genus also suffers from ash dieback fungus in Europe and weak branch unions that split in storms.

Native Range

Fraxinus spp. occurs throughout the temperate Northern Hemisphere across North America, Europe, and Asia, with a few species reaching subtropical climates. North American natives include F. americana, F. pennsylvanica, and F. nigra.

Suggested Uses

Historically grown as shade and street trees for their fast growth and tolerance of tough sites, though the emerald ash borer has ended most new planting in North America. The wood is harvested for tool handles, flooring, furniture, and sports equipment. Seeds and insects associated with ash feed birds and other wildlife.

How to Identify

Identify Fraxinus spp. by opposite, pinnately compound leaves and stout twigs with opposite buds, a pairing shared with few other trees. The bark of mature trees forms a tight diamond-patterned ridge network. Female trees carry drooping clusters of paddle-shaped, single-winged samaras that ripen brown in late summer. The opposite, compound leaves separate ash from walnuts and hickories, which bear alternate compound leaves.

Appearance

Size & Dimensions

Height30' - 120'

Width/Spread30' - 60'

Reaches mature size in approximately 20 years

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~2 weeks

Spring

Flowering occurs in spring, generally April and May, before or as the leaves unfold. Male and female flowers are usually borne on separate trees, are small and petalless, and rely on wind for pollination. The flowers produce no nectar and little display. Samaras ripen from late summer into fall and may hang on the tree into winter.

Detailed Descriptions

Flower Description

green to purple

Foliage Description

green

Growing Conditions

Sun Requirements

SunFull Sun SunPartial Shade

Requires 6-12 hours of direct sunlight daily

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range5.0 - 7.5(Neutral)

357912

Soil Types

loam clay sand

Drainagewell drained

Water & Climate

Water Needs

Medium

Frost Tolerance

hardy

Time to Maturity

moderate; about 20-30 feet (6-9 m) in 20 years

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Plants in this genus grow in full sun and adapt to a wide range of soils from sandy to clay across soil pH 5.0-7.5, tolerating both wet bottomlands and dry urban sites depending on species. Established trees tolerate drought, heat, and compacted soil, which made green ash a common street tree before the emerald ash borer arrived. In borer-affected regions, untreated trees decline within a few years, and insecticide treatment must be repeated to keep them alive. Growth is moderate to fast, around 12-24 inches (30-60 cm) per year. Other problems include ash dieback, anthracnose, cankers, and storm breakage at weak forks. Hardiness spans USDA zones 3-9 depending on species.

Pruning

Prune in late winter or early spring while dormant to remove dead, crossing, or weakly attached branches and to develop strong scaffold limbs on young trees. Training to a single leader reduces the split-prone forks common in the genus. Mature trees need little pruning beyond deadwood removal.