autumn olive, Bonsai, Elaeagnus, oleander, species, umbellata
Like many plant species, Elaeagnus umbellata goes by many names. I call it Autumn Olive. It doesn’t belong in my part of the world, but it grows wild here nonetheless on the sides of roads and edges of wooded areas. I have kept a few individual plants as bonsai for several years, and below is a collection of my observations and conclusions about the species as a bonsai subject.
BONSAI ARTICLES SHOULD ALWAYS INCLUDE CONTEXT: I live in Northern Virginia, USA, in USDA plant hardiness zone 7a, where the average annual minimum temperature is 0 to 5 degrees F (-18 to -15 C). Autumn Olive is native to Eastern Asia and is considered a hardy, aggressive, invasive species here and in other parts of the United States and Europe.
It’s important to point out that there are many Elaeagnus species and E. umbellata may not be the best of them for bonsai. You will find more abundant bonsai examples of E. multiflora aka Gumi, and E. pungens, a thorny variety of which there is a beautiful specimen at the National Bonsai and Penjing Museum in Washington D.C. I have also seen bonsai that I suspect are E. macrophylla and E. angustifolia, if not many more. Elaeagnus, the genus, offers much to the bonsai practitioner, and if E. umbellata is a variety accessible to you, I hope the information that follows is helpful.
This is a shrub
As you consider working with Autumn Olive, remember it is a shrub, not a tree. The practical ramifications of this are both negative and positive. Because it is “just” a shrub, the trunks thicken slowly and won’t likely ever be huge, so make sure that specimens you collect already have the girth you’d like to work with. Once in a pot you should expect that growth to slow to nearly imperceptible.
The species is apically dominant, but not as strongly as many true trees. Some attention should be paid to controlling the top growth when trying to promote growth down low and on side branches, but on the other hand, back budding does happen readily, including down the trunk. In fact, you should watch for suckers developing at the base of the tree and base of branches and remove those that are unwanted to prevent them from sapping energy from the rest of the tree.
Root base challenges
In my experiences collecting Autumn Olive, and examining potential specimens in areas where I am allowed to dig, I have found a pattern in the root growth that can be problematic. It seems very common that the root base is made up of two primary roots heading in opposite directions rather than a fuller, radial spread of surface roots that is desired in bonsai. This isn’t a deal breaker for the whole species, it’s just something to be aware of when collecting. Make sure to dig down to find the nebari so you know what you are dealing with, and realize if you find an Autumn Olive with a nice root spread, you’ve got a special thing.
If you collect a specimen with some thick primary roots, you may need to do a little root work to improve the aesthetics. The example above shows some initial carving to split a large surface root into two separate visual elements. After carving, I sealed the cuts, and I expect to revisit this site over the years to refine and improve as the roots heal and grow.
I should temper any optimism related to this sort of root work with a warning that Autumn Olive heal over (roll over) very slowly. I mentioned that the trunk thickens slowly, and this impacts how well this species will heal over cuts. Even smaller branch cuts can take years to heal over, and large scars should be accepted as features rather than hoping that a heal over will solve the issue eventually.
An effective practice on this species that works well on most is to allow a strong branch to grow just above or below a cut. The growth of that branch will aid the development of new vascular tissue around the deadwood. The strongest area of new tissue in the image above is where a large branch emerges at the top.
Autumn Olive is a deciduous species, but in the relatively mild winters of Northern Virginia they will hold onto leaves well into the winter. The newest leaves to grow are the ones that will linger longest such that older, inner leaves may turn yellow and fall in late Autumn while a few leaves toward the tips of branches may hold on through December and beyond.
I often remove all of the remaining leaves before placing these in their winter storage location, and certainly if I am going to do any winter wiring.
In addition to staying green longer, in my region they also start growing quite early. The image below was taken in the last week of February. New leaves were already starting to emerge, and late cold snaps, as we have had this week in early March, will simply slow the growth without causing any apparent damage.
Autumn Olive leaves can range in size naturally and reduce well with partial and full defoliation techniques. Out of caution, I have avoided full defoliation in consecutive years since that can strain the tree.
E. umbellata is not a perfect species, but one of the approaches to bonsai I really appreciate is taking a piece of unwanted plant material and making it into something beautiful. This species is widely available in my area and it’s not really wanted anywhere it is found here. If I can figure out the best way to work with it, then digging these and putting them in a pot is a win-win.
I hope my observations help you as well. If you’d like to read more about my Autumn Olive bonsai, check out any of these older posts.
- Shohin Elaeagnus
- Two Elaeagnus
- The Three Bears
- Vigorous Deciduous