World Plants

Acer negundo (Box Elder or Manitoba Maple)

Michael's Opinion

A tree not worthy of planting for any reason, since if planted by the homeowner it will ensure a life of regret. Even the wood, rich in sap, is difficult to burn. Seen as a unkempt, broad spreading, weedy tree, that produces suckers and seeds in quantity at the slightest provocation. Thankfully often short lived.

Botanical Information

Family	Sapindaceae (Aceraceae)
Genus	Acer
Species	negundo
Category	Woody
Type	Tree (deciduous)
Origin	Western Canada.
Pronunciation

Details

USDA Hardiness Zone	3-9
USDA Hardiness Ref.
Canadian Hardiness Zone	2
Canada Hardiness Ref.
RHS Hardiness Zone	H7
RHS Hardiness Ref.
Temperature (°C)	-40
Temperature (°F)	-45 - (-10)
Height	15 m
Spread	12-15 m
Growth	Fast
Flowering Period	April

Description and Growing Information

General Description	A horrible, weedy, unkempt, weak wooded, nasty tree. My apologies to the western provinces of Canada where this tree is native and is grown as an ornamental.
ID Characteristic	Easily identifiable by its compound leaves, young twigs are covered in a blue bloom that when rubbed off reveals the smooth olive covered stems beneath. Foliage is bitterly aromatic when crushed.
Shape	Often broader than high; about 15 m.
Landscape	None, in fact it should not be used in the landscape since the wood is very weak and limbs may come crashing down in winter storms. Cultivars may be accepted, as they are often slower growing and do not reach the size or breadth of the species.
Propagation	Seed, 2-3 months at 4°C. For cultivars grafted on species rootstock.
Cultivation	Often a volunteer species in neglected fields, meadows and hedgerows where the soil is often rich.
Pests	Many minor infestations such as leaf miners, galling insects and aphids, unfortunately not any that affect the tree vigorously enough to ensure its demise.
Notable Specimens	None, but many large specimens throughout the province.
Habitat	Plains of Western Canada.
Bark/Stem Description	Shallow fissured, grey to beige in colour.
Flower/Leaf Bud Description	Buds are about 5 mm long, two scaled and covered with silky hairs.
Leaf Description	Rich, almost shiny, light to medium dark green, leaves which are compound often with 7-9 leaflets to a leaf, leaves to 15 cm in length.
Flower Description	Flowers in dense clusters before the leaves emerge.
Fruit Description	Seeds held in large drooping clusters, often persisting into the winter months.
Colour Description	Pale yellow autumn colour not worthy of note.
Texture Description	Coarse, weedy textured plant.