Common Name: Box Elder

General Information

Acer negundo is a deciduous tree with an irregular, rounded crown; it can grow 15 - 20 metres tall. The bole is very short, dividing near the ground into a number of stout, wide-spreading or erect branches[]. The tree often produces suckers and can form thickets[].
The tree is harvested from the wild for local use as a food, medicine and source of wood. An ornamental plant[], there are several named varieties[].

Known Hazards

None known

Botanical References

, ,

Range

N. America - Nova Scotia to Florida, west to Manitoba and California

Habitat

Found in a variety of soil types, growing best in lowland sites along rivers, streams, ponds or seasonally flooded flats[].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Deciduous Tree
Height	21.00 m
Growth Rate	Fast
Pollinators	Bees
Self-fertile	No
Cultivation Status	Ornamental, Wild

Cultivation Details

Acer negundo is a very cold-hardy plant, able to tolerate temperatures down to around -18°c when dormant[]. Plants are hardy to about -40°c according to another report[].
Of easy cultivation, succeeding in most soils[] but preferring a rich moist well-drained soil and a sunny position[]. Grows well in heavy clay soils and in sandy soils[]. Tolerates a wide range of soils including poor dry ones[]. Plants often become chlorotic on very alkaline soils[].
A fast growing but short-lived tree in the wild, living for 75 - 100 years[, ]. It is fairly wind-tolerant[], but the branches have a tendency to break in strong winds[].
This species is cultivated commercially in Illinois for its sap[]. Another report says that this is one of the least productive species for sugar[].
The sugar content is inferior to Acer saccharum according to one report[] whilst another says that it is highly valued as a producer of sweet sap[]. The sugar from the sap of this tree is said to be whiter than that from other maples[]. To obtain the sap, bore a hole on the sunny side of the trunk into the sapwood about 1 metre above the ground at anytime from about January 1st until the leaves appear[]. The flow is best on a warm day after a frost[]. The best sap production comes from cold-winter areas with continental climates.
This tree is a bad companion plant that is said to inhibit the growth of neighbouring plants[, ].
This species is notably resistant to honey fungus[, ].
Very tolerant of pruning, it can regenerate from old wood if it is cut back hard[].
A dioecious species - both male and female forms must be grown if fruit and seed are required.

Edible Uses

The sap contains a reasonable quantity of sugar and can be used as a refreshing drink or be concentrated into a syrup[, , , , ]. The syrup is used as a sweetener on many foods.

Inner bark - raw or cooked. It can be dried, ground into a powder and then used as a thickener in soups etc or be added to cereal flours when making bread, cakes etc[]. The inner bark can also be boiled until the sugar crystallizes out of it[].

Self-sown seedlings, gathered in early spring, are eaten fresh or dried for later use[].

Seeds - cooked. The wings are removed and the seeds boiled then eaten hot[]. The seed is up to 12mm long and is produced in small clusters[].

Medicinal

A tea made from the inner bark is used as an emetic[, ].

Agroforestry Uses:

A fairly wind-tolerant tree, though with a tendency for large branches to break off in strong winds. It can be used in mixed plantings as a part of shelterbelt plantings[, ].
The plants fibrous root system and prolific seeding habit have led to its use in erosion control in some parts of the world[].

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[].

The heartwood is a creamy white; it is not clearly demarcated from the thick band of sapwood. The wood is soft, weak, light, close grained. It weighs 27lb per cubic foot[]. Of little commercial value, it is sometimes used for boxes, cheap furniture, interior finishing of houses, pulp etc[, , , , ]. Large trunk burls or knots have been used to make drums[].
The wood is used for fuel[].

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. The cuttings of this species usually root easily.
Budding onto A. negundo in early summer usually works well. The bud should develop a small shoot in the summer otherwise it is unlikely to survive the winter.