Alongside my garden are towering native swamp maples (Acer rubrum, more commonly called red maples), tulip poplars (Liriodendron tulipifera), and an occasional oak (Quercus rubra) and dogwood (Cornus florida) in the narrow swath of forest that is bisected by a small, spring fed creek. The native forest is a blessing, and sometimes a hindrance as thick branches crash to the ground after any gust of wind. The shallow roots of the maples make digging on this side of the garden a chore, and the resulting dry shade is a considerable challenge.
If you are expecting the autumn foliage of the native maples to be glorious in late October, think again, unless you favor faded yellow and spotted leaves to be in any way attractive (above). I refer to the maples as swamp maples rather than the more commonly used “red” maple because there’s not one trace of red to them. They’re all a sad yellow (unlike the glowing yellow of Sugar maple, Acer saccharum, or Trident maple, Acer buergeranum, below), and this is the predominant foliage color of any group of swamp maples that I’ve ever seen. Not just bordering my garden, but everywhere.
So, where do the maples with brilliant red autumn foliage that you see in the neighborhood come from? These are cultivars such as ‘Red Sunset’ (Acer rubrum ‘Red Sunset’, below) and ‘October Glory’ (and several others), trees that were initially selected from seedlings for one or more desirable characteristics. If I were to allow any number of the thousands of seeds that germinate annually in my garden from the forest’s maples to grow, there would be few trees that would grow to be identical. Many would appear the same, but there would be slight differences in leaf size, color, branching, or any number of characteristics that would hardly be noticed. A small percentage of seedlings would have red autumn foliage color.
If rooted cuttings, grafts, buds, or samples for tissue culture are taken from the red leafed tree, the newly propagated tree (a cultivar) will be a clone of the parent. Very often, seedlings from a cultivar will not duplicate the desirable characteristics of the parent tree, so many must be propagated asexually (rooted cuttings, tissue culture, etc.) rather than growing new trees from seed.
The question posed today is for you to consider which tree you favor, the yellow or red leafed tree? And, if you prefer (or demand) native trees, should cultivars be considered to be native, or not? Native tree purists insist that the cultivars are not native since they do not grow true from seed (among other reasons), but the red maple cultivars began as seedlings. These were not genetically modified, and they are not hybrids such as ‘Autumn Blaze’ maple (Acer x freemanii ‘Jeffersred’, below), a cross between silver (Acer saccharinum) and red maples with a fast growth habit and marvelous red autumn foliage.
In fact, an advantage of ‘Autumn Blaze’ is that it sets few seeds, so if these were growing in the forest bordering my garden I would spend many fewer hours plucking out the small seedlings. Cultivar maples ‘Sun Valley’ and ‘Brandywine’ are male selections, so these also set no seed. But, are they native, and does it make any difference to you? Or, is close enough, good enough?
I lean towards agreeing that the red maple cultivars are not natives, but to me the distinction is trivial. I regularly plant natives, but not exclusively, and I tend towards trees with outstanding characteristics (with red autumn foliage and seedless being my primary considerations in choosing a red maple). So, I would choose ‘Sun Valley’ or ‘Brandywine’ rather than ‘Red Sunset’ or ‘Autumn Blaze’, and any of the cultivars or the hybrid maple is preferable to the yellow leafed seedlings.
In fact, I won’t plant a red maple at all, not because of anything to do with it being native or not, or red autumn foliage. There are plenty of red maples in this neighborhood (too many?), and every other neighborhood, I suspect, and I’d like something a little different. There are too few katsuras (Cercidiphyllum japonicium), beech (Fagus), and any number of wonderful trees. Or, perhaps a blackgum should be considered, but do I plant the native or the cultivar ‘Wildfire’?
Next time, we’ll tackle dogwoods, and here there are similar choices to make. The native is a superb tree, but so are cultivars, and hybrids, and trees introduced from southeast Asia. So, here’s another worthy discussion for another day.