Before I discuss what cedar is, perhaps I’d better clarify what cedar isn’t. Eastern red cedar isn’t a Cedrus at all, it’s a juniper - Juniperus virginiana (which, BTW, is the “cedar” used as fragrant red cedar woodwork). Eastern white cedar and Western red cedar aren’t Cedrus either, they’re arborvitae - Thuja occidentalis and Thuja plicata, respectively. Incense cedar, Calocedrus decurrens, is close, but no cigar. Japanese cedar is Cryptomeria japonica.
When is a cedar not a cypress? When it’s a Chamaecyparis. Too add to all this wonderful mess, we have Chamaecyparis lawsoniana, the Port Orford cedar, and Chamaecyparis thyoides, the Western or Atlantic white cedar, which are actually considered false-cypresses (why not false-cedars?)
These distinctions, in the case of Cedrus, are mind-bogglingly important. The watering requirements for Cedrus are very different than those for false- cypress. And confuse Cedrus with Thuja? Cedrus likes it warm and dry, and has a reputation for being a high-strung, finicky bonsai (although those that grow cedar in something close to its natural Mediterranean climate report great success). Thuja could probably be kicked the length of your yard and stuck in the freezer for a few days. Not, of course, that I recommend this.)
Probably the easiest way to keep things straight is to remember that Cedrus is a very small genera. There are only four kinds of cedar and they all have pointy needles like pines, spruces and firs (the Pinaceae). The impostors (except Cryptomeria) all have scaly, frond-like foliage when mature (family Cupressaceae). All true cedars originated in the Old World - the Mediterranean and the Himalayas. Cedars are large evergreen trees with grey bark - smooth at first, becoming rough with age - and erect, woody cones. Cedar wood has historically been important in commerce, and remains popular today for its fine scent.
Most will need some frost protection. May need some protection from wind burn to prevent branch die back in colder areas.
Moderate in summer, reducing as the weather gets colder. Allow the soil to dry somewhat between waterings. Needles turn yellow when over-watered.
Every two weeks during spring and autumn. Stop feeding during the heat of midsummer.
Every 3-5 years in spring, Preferably before new white roots appear in February-April, using a fast-draining soil mix. Cedars do not like root disturbance, so repot only when necessary. C. atlas glauca is especially sensitive and needs extra humidity to avoid shedding its needles. If needle loss occurs, buds should soon burst forth. According to the Samsons, cedars do not like to be bare-rooted when being repotted.
Pruning and wiring:
Pinch back new shoots. Heavy pruning should be avoided, as the cedar takes quite a long time to heal pruning scars. If it is necessary, jinning branch stubs may be a more attractive option than leaving a scarred trunk. Brent Walston shared the following method of producing large trunks on Cedrus:
Decide how tall you want your tree to be, six times the diameter of the trunk is ideal, you can give yourself some leeway because it will increase in diameter while in training. Then look for a likely spot to cut the top off, I look for a set of close internodes around the height I want, this will give a good apex. About six inches above this point make a forty five degree angle cut on the BACK of the tree about halfway through. Grab the top of the tree and break it, pulling it down and ripping the wood and bark on the front of the tree. You can pull it down as far as you want exposed wood to show, all the way to the crown if you like, but not into the roots or rot will result. When pulled down to the right position twist and break it as much as possible to get it free at this point, you may have to do some cutting, but breaking it free looks more natural. At the cut portion of the top, split the wood vertically with branch cutters and pull down bundles of fibres with pliers until no saw cut marks are visible. The effect that you want is that of a lightening struck tree. I grab the fibres with the pliers and roll the pliers down the trunk rather than give a straight pull, you can exert much more force this way.
The tree may be wired at any time, but the branches take a while to set, and the wire may need to be on for three months up to a year. If it’s on that long, be sure to check it often to make sure it doesn’t cut into the bark!
Soak seeds for 48 hours, then one month cold pre-treatment before sowing. In my experience, the seeds are susceptible to mould, and soaking in a weak bleach solution before cold treatment may be desired. Seeds should be sown in spring, preferably in May. Cedar seedlings should be potted up and staked after their first year. Cyprian cedar and blue Atlas cedar are usually propagated through grafting, which can be done in late summer. Softwood cuttings may be taken in spring, or hardwood cuttings taken in autumn.
Pests and Diseases:
Bark beetles, caterpillars, honey fungus.
Some species suitable for bonsai:
Cedrus atlantica: Atlantic cedar, Atlas cedar - a short-needled (less than 1 inch) variety, the Atlas cedar has pale grey bark and a conical profile. The species has green to bluish-green needles. Thrives in zones 6-8.
Cedrus atlantica glauca: blue Atlas cedar - A steel blue cultivar. Cedrus brevifolia: Cyprus cedar, Cyprian cedar - A very slow growing tree, with short, dark green needles.
Cedrus deodara: Deodar cedar, Indian cedar - the largest cedar, it is reputed to grow up to 250 feet in Afghanistan. It has deep green 1 1/2 inch long needles which may turn gray in hot, dry areas. Best used only for large size bonsai, it lacks the refinement of other cedars. Deodar cedar has an unusual profile. Although conical, it grows with a “dropper leader,” which means that the top of the tree tends to form a drooping arch (which would make it, I suppose, “formal drooping style.”) The most tender cedar, zones 7-9.
Cedrus libani: Cedar of Lebanon - in nature, Cedar of Lebanon can grow to be 100 feet tall. It has an unusually spreading, rounded profile for a conifer, and is often seen with multiple trunks. Needle length is about 1 inch. Zones 6-8.
Cedrus libani ‘Green Prince’ - Grows very slowly, only 18 inches in ten years. Very short dark green, almost black, needles. Highly recommended for bonsai, but rare and expensive.
Cedrus libani ‘Nana’: dwarf cedar of Lebanon
Compiled by Sabrina Caine