Common Name: Oregon Maple

General Information

Acer macrophyllum is a deciduous tree that can grow 25 - 30 metres tall. The straight, cylindrical bole is unbranched for much of its height and can be 60 - 90cm in diameter[].
The tree has a wide range of uses for food, medicine and as a source of materials. Most of these are local uses, but it also produces one of the most valuable hardwood timbers of western N. America and it is often harvested for commercial use. A very ornamental plant, it can be cultivated in large gardens and parks etc[].

Known Hazards

None known

Botanical References

, ,

Range

Western N. America - southern Alaska to California

Habitat

Found in a variety of soil types, on the banks of streams, in rich bottom lands and on rocky slopes of mountain valleys[, ].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Deciduous Tree
Height	30.00 m
Growth Rate	Fast
Pollinators	Insects
Cultivation Status	Ornamental, Wild

Cultivation Details

Acer macrophyllum is a moderately cold-hardy plant, able to tolerate temperatures down to around -20°c when dormant[]. This species generally thrives in cultivation, though it can suffer damage in a severe winter if that follows a mild autumn[].
Of easy cultivation, it prefers a good moist well-drained soil[] and a position that is at least moderately sunny[, ]. Grows well in heavy clay soils. Chlorosis can sometimes develop as a result of iron deficiency when the plants are grown in alkaline soils, but in general maples are not fussy as to soil pH.
The best sap production comes from cold-winter areas with continental climates. The tree trunk is tapped in the early spring, the sap flowing better on warm sunny days following a frost.
Growth of young plants is rapid in the wild, slowing down after 40 - 50 years, with a maximum life span of about 275 years[].
Most maples are bad companion plants, inhibiting the growth of nearby plants[, ].

Edible Uses

The sap contains a certain amount of sugar and can either be used as a drink, or can be concentrated into a syrup by boiling off the water[, , ]. The syrup is used as a sweetener on many foods. The concentration of sugar is somewhat lower than in the sugar maples (A. saccharum).

Inner bark[]. Eaten in small quantities with oil[]. No more details are given but inner bark is often dried, ground into a powder and then used as a thickening in soups etc or mixed with cereals when making bread.

The leaves, when wrapped round food during baking, impart a nice flavour to the food[, ].

Yellow flower clusters - raw. They are sweet with nectar[].

Seeds - sprouted and then boiled[]. The sprouted seeds are generally bitter, but the young shoots are quite sweet and juicy[]. The seeds are about 6mm long and are produced in small clusters[].

Medicinal

An infusion of the bark has been used in the treatment of TB[].

The raw sap has been used as a tonic[].

Other Uses

We have two reports that the leaves of maple species, when laid in layers between crops such as apples, carrots and potatoes, have a preservative effect[, ]. The reports do not name any specific species[].

A sticky gum obtained from the buds in spring has been mixed with oil and used as a hair tonic[].

A fibre obtained from the inner bark is used for making scouring pads, rope and crude dresses[, , ]. It was harvested in the spring and was also used in making baskets[].

Young stems are used as coarse twine warp and weft in the manufacture of baskets[].

The heartwood is a rich brown, tinged with red; the thick layer of sapwood is lighter in colour, often nearly white. The wood is light in weight, soft, not strong, close grained. Specimens with the grain beautifully curled and contorted are common. It is highly valued for timber, furniture and indoor use and is also used for carving bowls, axe and broom handles, veneer etc[, , , , , , ].
The wood makes an excellent fuel, producing a hot smokeless flame[].

Propagation

Seed - best sown as soon as it is ripe in a cold frame, it usually germinates in the following spring. Pre-soak stored seed for 24 hours and then stratify for 2 - 4 months at 1 - 8°c. It can be slow to germinate. The seed can be harvested 'green' (when it has fully developed but before it has dried and produced any germination inhibitors) and sown immediately. It should germinate in late winter. If the seed is harvested too soon it will produce very weak plants or no plants at all[, ]. When large enough to handle, prick the seedlings out into individual pots and grow them on until they are 20cm or more tall before planting them out in their permanent positions.
Layering, which takes about 12 months, is successful with most species in this genus.
Cuttings of young shoots in early summer . The cuttings should have 2 - 3 pairs of leaves, plus one pair of buds at the base. Remove a very thin slice of bark at the base of the cutting, rooting is improved if a rooting hormone is used. The rooted cuttings must show new growth during the summer before being potted up otherwise they are unlikely to survive the winter.