Common Name: Sugar Maple

General Information

Acer saccharum is a deciduous tree developing a broad, round-topped dome at maturity; it usually grows 12 - 25 metres tall, though it can reach 30 - 35 metres or more. The straight, cylindrical bole can be free of branches for up to 20 metres and around 90 - 120cm in diameter[].
The sugar maple has a wide range of uses as a food, medicine and source of materials. It is especially valued as the major source of maple syrup, and has become the centre of a multi-billion dollar industry in the U.S. And Canada[, , ]. The tree is also the source of a high quality timber and is considered by many to be the most valuable hardwood tree in N. America. A very ornamental tree, it can be grown in larger gardens, parks etc[].

Known Hazards

None known

Botanical References

, ,

Range

Eastern N. America - Newfoundland to Georgia, west to Minnesota and Texas.

Habitat

Found in a variety of soil types, doing best in deep rich well-drained soils from sea level to 1,600 metres[]. Rich usually hilly woods[].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Deciduous Tree
Height	25.00 m
Growth Rate	Slow
Pollinators	Insects
Cultivation Status	Ornamental, Wild

Cultivation Details

Acer saccharum is a very cold-hardy plant, able to tolerate temperatures down to around -35°c when dormant[]. Down to around -45°c according to another report[].
Of easy cultivation, it prefers a good moist well-drained soil but succeeds on most soils[, ], though it is more likely to become chlorotic as a result of iron deficiency on alkaline soils. Grows well in heavy clay soils. Trees need full light and a lot of space[]. This species is one of the most shade tolerant of the N. American maples[]. It tolerates atmospheric pollution[] and so is often used as a street tree, though it can suffer from soil compaction and the use of salt on the roads in frosty weather. Tolerates a pH in the range 4.5 to 7.3.
The sap can be harvested in late winter or early spring[[], the flow is best on a warm sunny day after a frost[]. Trees on southern slopes in sandy soils give the best yields[].
It is best to make a hole about 7cm deep and about 1.3 metres above the ground[]. Yields of 40 - 100 litres per tree can be obtained[].
The best sap production comes from cold-winter areas with continental climates.
A fast-growing tree for its first 40 years in the wild[], this species is often not a great success in maritime climates[], though it does better than once thought[]. It grows well in Cornwall[]. In cultivation it has proved to be slow growing when young[]. Trees can live for 250 years in the wild[].
A bad companion plant, inhibiting the growth of nearby plants[, ].
There are some named varieties[].
The sap can be tapped within 10 - 15 years from seed but it does not flow so well in areas with mild winters[].

Edible Uses

The sap contains quite a large proportion of sugar. This can be used as a refreshing drink, or be concentrated into a syrup by boiling off the water[, , , , ]. The syrup is used as a sweetener on many foods. The sap contains 2 - 6% sugar, thus about 32 litres are required to make a litre of maple syrup[].

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 about 6mm long and is produced in small clusters[].

Inner bark - cooked. It is dried, ground into a powder and then used as a thickening in soups etc or mixed with cereals when making bread[, ].

Medicinal

A tea made from the inner bark is a blood tonic, diuretic and expectorant[]. It has been used in the treatment of coughs, diarrhoea etc[]. The inner bark has been used as an expectorant and cough remedy[].
A compound infusion of the bark has been used as drops in treating blindness[].

The sap has been used for treating sore eyes[].

Maple syrup is used in cough syrups and is also said to be a liver tonic and kidney cleanser[].

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 ashes of the wood are rich in alkali and yield large quantities of potash[].

The heartwood is light brown, tinged with red; the thin layer of sapwood is lighter in colour. The wood is close grained, tough, hard, heavy, strong, not very durable. It takes a high polish; remains smooth under abrasion; has a high shock-resistance; holds nails well; is fair in gluing; dries easily and shrinks moderately[, , , , ]. The wood weighs 43lb per cubic foot[]. The wood is used for a wide range of applications including furniture, flooring, turnery, musical instruments and ship building[, , , , ]. Accidental forms with the grain curled and contorted, known as curly maple and bird's eye maple, are common and are highly prized in cabinet making[].
The wood is a very good fuel, giving off a lot of heat and forming very hot embers[, ].

Propagation

Seed - best sown as soon as it is ripe in a cold frame, it usually germinates in the following spring. A lot of the seed is non-viable, it is best to cut a few open to see if there is an embryo[]. An average of 95% germination can be achieved from viable seed[]. Pre-soak stored seed for 24 hours and then stratify for 2 - 4 months at 1 - 8°c. It can be slow to germinate, sometimes taking two years[]. 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.