I took this picture of my first Sweet Autumn Clematis (clematis ternifolia) blooms last week. I would like to say that planting it was an honest mistake, but I really should have known that the "white flowering clematis" I purchased at a local nursery last fall would turn out to be SAC instead of the native clematis virginiana, a.k.a. virgin's bower, that I wanted.
The white flowers are delicately pretty on both plants, but a little research would have told me that the smooth leaves were a dead giveaway that it was the non-native SAC. Due diligence on plant purchases is usually part of my whole process, but I failed on this one... seduced, I am shamed to admit, by end-of-season sales.
For the record, I am not a "natives only" militant but I like to use natives whenever I can. I will gladly use non-natives, however, if they are well suited to the site, fit my purpose, and are well-behaved. That last point is where the SAC seems to fail.
My online research points to clematis ternifolia being more prone to escaping the garden and invading natural areas in zones warmer than mine, but it has been known to escape. It is also known for being rather aggressive--some prefer the terms "robust" or "strong grower"--even when it stays in its general area. In fact, I could not find a consensus on which thug designation (aggressive, invasive, etc.) should be given to the Sweet Autumn Clematis, if it even deserves one at all.
All of this grey area gave me a perfect excuse to keep it around--for a little while longer, at least--and I really considered leaving it alone. However, I found myself avoiding that corner of the garden so that I didn't have to feel the twinge of guilt that seeing the plant created in my stomach. It simply had to go.
Sounds a little melodramatic, I know... and I would never advise someone who had Sweet Autumn Clematis growing in their own garden to rip it out immediately, or even lecture them on its pros and cons. (Purple Loosestrife might be another story!) But I think that every gardener has his or her own comfort level on the issue of invasive plants, and I have discovered that I personally am not very tolerant of even possible problem children.
I'm going to sound a little Pollyannaish, I'm afraid, but I like to focus on the positive. I can't singlehandedly pull up all of the garlic mustard, purple loosestrife, and other plants listed on Ohio's Top Ten Invasives list. I can't capture and kill all of the Japanese beetles, Emerald Ash Borers, and other introduced pests, either.
What I can do, though, is pull out a vine that may be a problem, and replace it with a better-behaved native plant that won't give me a guilt complex. I am leaning toward lonicera sempervirens 'Blanche Sandman'--a native trumpet honeysuckle with showy red and yellow flowers.
Of course, I won't be buying or purchasing this beauty until spring. Just because it's a native doesn't mean it's not invasive or a problem, so... I need to do a lot more research! Anyone grow this native vine and care to share a review? I would greatly appreciate it...