Box Elder

Acer negundo

Physical Characteristics

Acer negundo is a deciduous Tree growing to 21 m (69ft) by 8 m (26ft) at a fast rate. See above for USDA hardiness. It is hardy to UK zone 2. It is in flower from April to May, and the seeds ripen from September to October. The species is dioecious (individual flowers are either male or female, but only one sex is to be found on any one plant so both male and female plants must be grown if seed is required). and is pollinated by Bees. The plant is not self-fertile. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils, prefers well-drained soil and can grow in heavy clay soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil. The plant can tolerates strong winds but not maritime exposure.

Distribution

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

Habitats

Woodland Garden Canopy;

Edible Uses

Edible Parts: Inner bark Leaves Sap Seed Edible Uses: Sweetener The sap contains a reasonable quantity of sugar and can be used as a refreshing drink or be concentrated into a syrup[11, 46, 61, 82, 159]. The syrup is used as a sweetener on many foods. The sugar content is inferior to A. saccharum according to one report[149] whilst another says that it is highly valued as a producer of sweet sap[183]. The sugar from the sap of this tree is said to be whiter than that from other maples[183]. 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[85]. The flow is best on a warm day after a frost[213]. The best sap production comes from cold-winter areas with continental climates. 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[257]. The inner bark can also be boiled until the sugar crystallizes out of it[257]. Self-sown seedlings, gathered in early spring, are eaten fresh or dried for later use[213]. Seeds - cooked. The wings are removed and the seeds boiled then eaten hot[213]. The seed is up to 12mm long and is produced in small clusters[82]. Foraging: Sap: Can be tapped for syrup, though yields are usually lower than sugar maple. Still, it provides a concentrated, mineral-rich sweetener after boiling [2-3]. Leaves: Young leaves are edible when cooked, though usually bitter. They can serve as an early-season vegetable [2-3]. Buds and Flowers: Presumed edible but under-documented. Male and female flowers grow on separate trees. Male flowers taste somewhat better and, once cooked, make a decent vegetable. Boiling reduces bitterness. Steeping pollen in hot water can produce a sweet amber drink, though caution is advised for those with pollen allergies. Fruits (samaras): Young fruits can be eaten before the wings toughen [2-3]. They are bitter raw but edible after cooking [2-3]. Inner Bark: Edible in survival situations but fibrous and of little value [2-3].

Medicinal Uses

Emetic A tea made from the inner bark is used as an emetic[222, 257].

Known Hazards

None known