Common Name: Green Ash

General Information

Fraxinus pennsylvanica is a deciduous tree that usually grows around 12 - 20 metres tall, but can reach 30 metres or more[, ]
The plant is harvested from the wild for local use as a medicine and source of materials. It has often been planted as an ornamental and street tree[].
Fraxinus pennsylvanica is suffering the devastating impact of a recently introduced invasive pest, the Emerald Ash Borer, that has rapidly spread across much of its native range and shows no sign of stopping. The disease causes virtually 100% fatality and regeneration is almost non-existent. A population decline of at least 80% over the next 100 years (and likely much faster than that) is assumed. The plant is classified as 'Critically Endangered' in the IUCN Red List of Threatened Species(2017)[].

Known Hazards

None known

Botanical References

, ,

Range

Central, Eastern and southern N. America - Alberta to Nova Scotia, south to New Mexico and Florida

Habitat

Streambanks, floodplains, wet upland sites and occasionally in swamps, rarely in pure stands; at elevations up to 3,000 metres[, , ].

Properties

Conservation Status	Critically Endangered
Edibility Rating
Medicinal Rating
Habit	Deciduous Tree
Height	20.00 m
Growth Rate	Fast
Pollinators	Wind
Self-fertile	No
Cultivation Status	Wild

Cultivation Details

Fraxinus pennsylvanica tolerates a broad range of temperatures and precipitation and is probably the most adaptable of all the ash species[]. It is a very cold-hardy plant, able to tolerate temperatures down to around -30°c when fully dormant[]
Prefers a deep loamy soil, even if it is on the heavy side[, ]. Most members of this genus are gross feeders and require a rich soil[, ]. Plants succeed when growing in exposed positions[] and also in alkaline soils[]. They tolerate atmospheric pollution[]. A fast-growing tree[]. Plants have little tolerance of shade[].
Cultivated as a timber tree in C. and S.E. Europe where it is sometimes naturalized[]. The cultivar 'Patmore' is disease resistant[].
A recently introduced invasive pest, the Emerald Ash Borer has rapidly spread across much of N. America and is devastating the genus Fraxinus. The borer infests and feeds on all the North American ash species it has so far encountered. The nature of the infestation (larval feeding in the phloem) effectively girdles trees as small as 25mm in diameter, which is many years before reproductive maturity, leading to death within five years of infestation. The borer therefore causes virtually 100% mortality of Ash populations. The Ash species are unable to persist for very long through vegetative reproduction, and seeds only remain viable in the soilfor at most 7 - 8 years, so regeneration after borer infestation is minimal or nonexistent. Furthermore, the borer persists in forests in low population densities after major ash population crashes, so the orphaned cohort of ash seedlings that remains is quickly infested as they reach a suitable size[].
A dioecious species - both male and female forms must be grown if fruit and seed are required.

Edible Uses

Inner bark - cooked[, , ]. The cambium layer can be scraped down in long, fluffy layers and cooked[]. It is said to taste like eggs[]. Inner bark can also be dried, ground into a powder and then used as a thickening in soups etc or mixed with cereals when making bread.

Medicinal

The bark and leaves are a bitter tonic[, ]. An infusion of the inner bark has been used in the treatment of depression and fatigue[].

The root is diuretic[].

Agroforestry Uses:

A fairly wind resistant tree, it can be grown as part of a shelterbelt planting, and is used in reforestation projects[, ].
Fraxinus species in general are gross feeders with an extensive, fibrous root system, which makes transplanting easy, but means that other species will often not grow well if planted nearby, especially if they are shallow rooted[],

Other Uses

A red dye is extracted from the bark[].

Logs of wood can be beaten with mauls to separate the growth layers, these layers can then be cut into strips and woven into baskets[].

The wood is hard, heavy, rather strong, tough, elastic, brittle, coarse-grained. It weighs 44lb per cubic foot. Used for tool handles, furniture etc[, , , , ]. The wood is of poorer quality than Fraxinus americana, though it is usually sold under that name[].

Propagation

The seed is best harvested green - as soon as it is fully developed but before it has fully dried on the tree - and can then be sown immediately in a cold frame[]. It usually germinates in the spring[]. Stored seed requires a period of cold stratification and is best sown as soon as possible in a cold frame[]. Prick out the seedlings into individual pots when they are large enough to handle and grow them on in a cold frame for their first winter. Plant them out into their permanent positions or a nursery bed in late spring or early summer of the following year.
If you have sufficient seed then it is possible to sow it directly into an outdoor seedbed, preferably in the autumn. Grow the seedlings on in the seedbed for 2 years before transplanting either to their permanent positions or to nursery beds.