- Written by Kevin R. Lee Kevin R. Lee
- Published: 03 November 2019 03 November 2019
In the eastern forests people enjoy nearly ten native maples, some introduced species plus the many gorgeous Japanese maples that come with kinder and gentler hardiness zones. Here in zone 3 we are very happy for the handful we have. Some Oriental maples are used here as accents, mostly as annuals. Perhaps someday a oriental maple will be bred to these harsh winters , we can only hope.
For now we will discuss the Manitoba maple. This stalwart westerner is the only full size maple grown here. Maples are dioecious trees, separate male and female trees, like the poplar family. If you really want this large tree, too large for most suburban lots, buy a male. the female is extremely fecund, producing thousands of double-winged seeds. The male clone Baron is a good choice.
The Amur maple is a long-time welcome guest from Asia, very hardy. Its sharp three-lobed leaves turn a good red in the right year. A little fussy about high pH clay soils, they sometimes exhibit chlorosis. I have never seen an Amur taller than 25 feet and with trunk diameters of about a foot. With a slow-growing, multi-trunked natural bonzai look, it's highly recommended.
The Tatarian maple is another good choice for a smaller tree, similar in growth habit to the Amur. There is a variety called Hot Wings, which describes the crimson red seeds, quite showy. The Tatarian has saw-edged leaves but not as deeply indented as the Amur.
There are two eastern maples that do well here, the Norway maple and the Silver maple. Both of these have much more of a traditional large maple leaf, the Silver is deeply insised with a flashing white on the back of the leaf like a white poplar. Try to find a prairie hardy grown tree in either case.
Maples have very few problems, especially the Manitoba which has passed the strictest survival test, of being used as a prairie shelter belt tree to guard prairie home sites. There is an aphid sometimes called the box elder aphid, Periphyllus negundinis, which on a peak population year can defoliate these maples. I have seen this once in my carrer. To give you a idea of the focus of this aphid, the latin binomial of the Manitoba maple is Acer negundo, the aphids species name is negundinis. The defoliated trees leafed out the following year.
Pruning is best done in the summer, or when the tree is in full leaf and green, not yellow. And not in winter. Maples belong to a group of trees whose wood is called diffuse porous. This means that the active upward transport vessels are laid down evenly throughout the growth ring each year. If diffuse porous trees are wounded during the dormant period, when spring comes they flush out a lot of sap trying to deal with the wound. This is the story of the making of maple syrup. Once the tree leafs out the sap flow from the wound quits. If pruned during the growing season, when the tree is full of green leaves, the tree will not lose any sap from the wound, or pruning sites.