Today someone asked me if an acer negundo was a good choice for their backyard. (Not a good choice in our area). I'm not a woody expert by any means, it just came up in conversation. My response was "ummm, wellllll" and then I remembered what I learned in a course I took on the woodys in our area and I responded "That tree is more suitable for reclamation uses, not for gardens". Thought I'd share that with woody fans although it probably would be appropriate for herbaceous plants too. Les
Multiple cultivars are commercially important and popular, among them 'Flamingo', 'Kelly's Gold' and 'Sensation'. http://www.jfschmidt.com/articles/sensation_boxelder/
It has a tendency to brittle branches, which makes it unsuitable for planting in places where people might be injured or killed by falling branches. Also often fairly short-lived. Conversely, its tolerance of very poor soil is what makes it suitable for reclamation of degraded land such as old mine waste heaps. So there is reason in what you were taught!
A more mannerly growth habit and improved branch structure results in as tough and adaptable tree that is less susceptible to storm damage than the species --Article at link above
Seedling box elders were once widely planted as fast-growing shade trees. Now mostly grafted cultivars are sold. The species is tolerant of difficult conditions, but does not age well in cultivation, posing problems such as breaking limbs. Still, the wholesale condemnation with which some people dismiss it is unfair and narrow-minded --A. Jacobson, North American Landscape Trees (1996, Ten Speed Press)
The reason Acer negundo is a poor choice locally (i.e. Canadian prairies) is rather less due to weak wood and short lifespan, and much more due to pervasive aphid infestation. The aphids secrete honeydew which falls on anything beneath the trees (lawn furniture in the case of shade trees, cars in the case of boulevard plantings) and then black mold forms on the honeydew. It is difficult to remove, and even seems to be rather harmful to the finishes on cars.
Manitoba Maples - Acer negundo - where do I start? I vascilate from hating them to liking them (somewhat and sometimes). Sometimes you get some that grow fairly straight and look like a reasonable tree for most of their lives. And other times you'll get one that won't stop suckering no matter what you do to try to stop it. If you're unfortunate to have a female tree then you become "blessed" with million of seedlings popping up everywhere in your garden; if you miss one, in couple of years you notice this small tree and if you don't pull it out then next thing you know it's a tree and you need to excavate around the trunk to get it out. I had two large specimens which provided shade for a newly made shade garden. One had three trunks and the other was single trunked. Both extended over a grass pathway over the other side of the shade garden, creating a tunnel effect. It was beautiful. Then last winter (06-07) we had a small ice storm before the ground froze and they both came out of the ground, falling onto parts of my garden. All of a sudden, my shade garden turned into a sun border. Hostas started burning in the summer of 07 and it really changed the look of things. I've learned to appreciate the new look. Some of the Manitoba Maples are growing as "weed" trees around the foundation of an old barn, some inside the foundation. Although they've been good in creating temporary shade, some are now falling and need to be removed. They are, at best, a very temporary inhabitant of a landscape. Even though we find many faults with them, they have their place. They just need to be "managed" more than most other trees. As for all those seeds and aphids, I've seen large flocks of Evening Grosbeaks congregate on them during the winter to feed on the seeds; and during the growing season, the aphids attract a multitude of birds who feast on them. There is always two sides to every coin.