Fraxinus Americana (White Ash), Nigra (Black Ash), Pynnsilvanica (Green Ash)

by John Brouwer

Ash trees are very common in our climate zone. We have a number in our co-op along the northwest exit and around the fire pit. White ash is most common and is the ash found extensively along city streets. It is an average tree growing to up to 80 feet. Street trees never reach that height because of pruning. The white ash has a leaf composed of 5 to 7 leaflets. Black Ash and Green Ash are very similar to White Ash. The mountain ash having white flowers and showy red berries is a completely different tree.

Before it was replaced by aluminum and composites, ash was used as tool handles, oars, hockey sticks, and baseball bats. Babe Ruth's home runs were all hit using an ash bat. In earlier times ash was used in the carriage trade because of its flexibility and then found extensive use in the early airplanes.

The English longbow and its arrows were often made of ash. It was also a popular fuel as ash logs will burn without curing.

Black Ash was used extensively by native cultures to make baskets. The trunks are soaked in water for over a year and the wood can then be split into thin supple strands which can be dyed and woven. As black ash is now scarce very native communities have established black ash nurseries to replenish stock.

Ancient mythologies from various traditions give a prominent role to ash trees. In common with a few other trees, European ash leaves and twigs exude a sweet sticky sap in the summer which aphids convert to a honey-like substance – hence honeydew and manna. The ancients viewed the ash as the giver of honey which along with acorns were a staple in the diet. The infant Zeus was fed by ash honey. Germanic mythology has the first person formed from an ash tree.

Druidic wands were made of ash. The mythical witch brooms were made of birch twigs fastened with willow ties onto ash handles. The Nimbus 2000 is made of ash with a birch bush.

However the Canadian manufacturers of the Nimbus 2000 and the Firebolt are now in trouble.

Eastern ash trees are threatened by the emerald ash borer an insect thought to have be carried into North America on pallet wood from Asia in 2002. The borer has killed thousands of ash trees in Michigan and Essex, Kent and Elgin counties. If you are driving along the 401 you may recall seeing signs prohibiting movement of wood from this south-western zone. This is a regulation designed to stop the further distribution of the borer as it readily migrates inside pieces of wood.

The emerald ash borer larvae live just under the bark and borrow and consume the cambrium cell layers which carry all the nutrients in the tree. Infected trees wither and die (can be within two years of infection). The borers first disconnect patches of cambrium and keep going until the tunnels finally encircle the whole tree preventing all nutrient transport. A little ½ cm. Insect can kill a 200 year old healthy tree in two years.

In order to control the spread of the emerald ash borer the Ministry of Natural Resources removed all ash trees for a 10 km swath from Lake Huron to Lake Erie in 2006. This doesn't appear to have been successful, as emerald ash borer has now also been discovered in several location within Toronto.

Local ash trees are joining the millions victims of globalization. The experts recommend maintaining tree species diversity so that the spread of these and other insects and diseases is hindered and other trees can take over when some species are threatened. As a layman, I would encourage woodpeckers.

August 2008