Box Elder (Acer interius)
At a glance
- Lifecycle
- Perennial (hardy)
- Exposure
- Full sun
Cultivation
We have very little information on this species, though judging by its native range it should be hardy in many parts of Britain. It is closely related to A. negundo and, like that species, is probably dioecious. The following notes are based on the general needs of the genus. Of easy cultivation, it prefers a good moist well-drained soil. 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. Most maples are bad companion plants, inhibiting the growth of nearby plants.
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 June or July. 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.
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 considerably lower than in the sugar maples (A. saccharum). The tree trunk is tapped in the early spring, the sap flowing better on warm sunny days following a frost. The best sap production comes from cold-winter areas with continental climates.
Material uses
The leaves are packed around apples, rootcrops etc to help preserve them. The wood is soft and weak, weighing about 27lb per cubic foot.
Habitat
Riversides.
Native range
Northern N. America - Kansas, Nebraska and the Rocky Mountains.