Whoever named this Deep South native the bottlebrush buckeye must have had one mighty big bottle. The inflorescences range from 8-12″ on the species to 18-30″! the cultivar ‘Rogers.” This is a plant I recall seeing only twice in the Seattle area and I don’t understand its scarcity. Summer-blooming shrubs aren’t very common and the inflorescences on Aesculus parviflora are big, beautiful and eye-catching. The shrub itself is okay too. So is there some big, secret downside to this plan that explains why you don’t see it all over Seattle? Not that I could find.
First, I’ll go right out there and say that I’m not 100% sure the shrub shown in these pictures is A. parviflora, although it sure looks like it, right down to the red anthers. If this is some other exotic Aesculus that someone recognizes, let me know. For the rest of this post I’m just going to assume my i.d. is right.
WHAT ARE THE POTENTIAL DOWNSIDES?
So back to what could be the problem with the bottlebrush buckeye. Aesculus parviflora is a member of the horsechestnut tribe. The horsechestnut itself (Aesculus hippocastanum) is a big, messy tree. The leaves are large and plentiful and probably can asphyxiate quite a few plants or small, unwary animals if they aren’t raked up in the fall. They drop really big, hard, spiny fruits. A. parviflora has the same large, palmately compound leaves and large (1-3″), hard fruits. Since A. parviflora is a shrub, neither the leaf nor the fruit drop is really a problem. Don’t grow anything underneath it that might get smothered unless you’re prepared to rake. According to Dirr in his Manual of Woody Landscape Plants* worrying about what grows under the bottlebrush buckeye may be a moot point since nothing much wants to grow there anyway. Also, there may be little fruit here. Dirr notes that plants grown in the north tend to have less fruit, perhaps due to the shortness of the growing season. Our growing season (the period from last to first frost) is long but pretty wussy compared to what this Deep South native plant is used to.
Other downsides, the shrub is deciduous, losing its large leaves in the fall so you’re left with a bare plant. My man Dirr notes that the tree has “excellent form and texture in the branching structure” so it probably is better looking than a forsythia during the winter. (Photos of shrub in winter available in about 4-5 months.) The shrub will likely want some summer water, coming from the Deep South. It’s a big shrub, 8-12′ H x 8-15′ W. Now there’s a problem for a lot of city gardens – that would take up one whole side of my front yard. Limbing it up and growing things underneath it is likely a no-go as well. It takes sun to part shade.
So why isn’t it grown here in the land of similarly-sized, window engulfing rhodies and camellias? Probably because it just hasn’t been put out there in the nurseries. It may not flower at a young age (the age at which you buy plants) and so people walk on by, not knowing what they’re missing. It’s also deciduous and even if its branching structure is pleasant I bet it doesn’t enhance the winter landscape. It probably just isn’t a blight on it.
If I had a bigger yard I’d definitely try to get ahold of one of these for its stupendous summer flowers. The whopping flower panicles and large, palmately compound leaves give the plant a tropical look. Even when not in flower the leaves alone are a nice change from the normal rounded to elliptical leaves too.
*Michael Dirr, Manual of Woody Landscape Plants, is a hugely useful book if you are a plant geek and can usually at least tell the genus of the plant you’re looking at. There are no photos but there are some line drawings showing things like the shape of the leaf or the arrangement of the bud scales. I use it quite often but at $60+ it’s definitely not for everyone.