The Cedar Elm is among my chosen five of the best bonsai trees for beginners. Cedar elm, Ulmus Crassifolia, is a member of the Elm family, Ulmaceae.
Its natural range is East Texas into Northern Louisiana and Southern Arkansas. It’s a primary species, growing to heights of 80’.
The leaves are:
- elliptical or lance-shaped,
- sometimes blunt at the tip and sometimes sharp-pointed,
- 1-2” long and ½ to 1” wide.
- a shiny dark green above with a leathery feel,
- hairy beneath,
- coarsely saw-toothed with rounded teeth (the rounded teeth of the cedar elm’s leaves are about the only way to distinguish between cedar elm and winged elm in young specimens).
The bark of cedar elm is light brown and furrowed into broad, scaly ridges. It takes at least a decade before bark begins to form.
Growth habit: cedar elm backbuds very well on old wood. The specimen pictured below was estimated to be about 40 years old despite only having a trunk diameter of 1-1/2”. It had only a single branch when collected, but produced ample buds to allow for proper development of the tree’s structure.
Cedar elm has two or three rounds of growth each season, which allows for thickening of branches that require it and development of a fine branch structure which makes your bonsai look like a full-sized tree in nature.
Leaf-size reduction: the leaves easily reduce to ½” with ramification and diligent pinching.
Ramification: outstanding over the course of three or four years, as the new branches develop shoots in each leaf axil. Eventually you will need to do so-called renewal pruning to thin the interior of your bonsai.
Here’s a sequence showing development of a nice cedar elm over the course of a single year. Notice the number one branch and how quickly it thickens by growing untrimmed, then finally being cut back to encourage ramification:
Root growth: as with other elms,
- root growth is vigorous enough to require root-pruning every other year, every third year as an absolute maximum to prevent weakening of the tree, and
- the roots must be pruned with a very sharp pair of shears as the bark tends to pull away from the inner core very easily.
Like winged elm, cedar elm gets “tired” foliage in late summer. Healthy specimens can be defoliated in late summer, but the practice is not recommended but every other year.
Sources of Cedar Elm
Cedar elm is available commercially, but frankly the best source for the species is collected specimens. They are available in the bonsai trade.
Cedar elm can also be grown from hardwood cuttings taken in late spring. I grow cuttings on in the ground for more rapid development.
If you collect your own: cedar elm has a stout wood, so I always recommend use of a cordless reciprocating saw to make the work easier.
- Cut the trunk to roughly 12-24”, then sever the lateral roots to within 4-6” of the trunk.
- Thrust the blade up under the tree and sever the taproot.
- Most trees should be out of the ground in under five minutes using this tool.
Once it’s time to pot the tree initially, first wash off all the native soil. Then re-cut the roots closer to the trunk in anticipation of the eventual bonsai container.
New roots will sprout mostly from the cut ends of the larger roots, so dust near the ends with rooting powder.
Pot in prepared soil. Be sure to bury the surface roots to ensure they don’t dry out as the tree recovers.
As a final step, seal every cut on the trunk that’s ¼” or greater in diameter with cut paste.
Watering: normal watering routine. Cedar elm is drought tolerant, but bonsai should never be allowed to dry out completely. Always use a well-draining soil.
Feeding: either organic or inorganic at full strength during the growing season. No special requirements.
So What Do You Think?
This is a great tree for beginners or even seasoned bonsai artists. But I would really enjoy hearing your thoughts and your suggestions! I’m always happy to answer any questions you have. Just leave your comment(s) below and then expect to hear back from me.