Plant taxonomy classifies Hinoki cypress as Chamaecyparis obtusa. Hinokis are actually a type of false cypress, as indicated by their genus name, Chamaecyparis. "Gracilis" is the name of the cultivar dealt with here, the common name for which is "Slender Hinoki cypress." The Slender cultivar is not a full dwarf Hinoki cypress (see below), but it is compact enough for most landscaping needs.
Chamaecyparis obtusa Gracilis trees are intermediate-sized or "semi-dwarf" Hinoki cypresses. They are more compact (15 feet tall at maturity, and about 5 feet wide) than the species trees, which reach more than 50 feet in height. But they are not as short as 'Nana Gracilis,' the full dwarf (9 feet tall at maturity).
The flattish sprays of scale-like needles will remind some of arborvitae, but the sprays of Hinoki cypress trees curl down slightly. Adding further charm to a mature plant is its nodding top and arching branches, which also droop at their tips.
Although not a weeping tree, the "droopy" appearance of a mature Hinoki cypress (in its foliage sprays, branch tips, and top) is certainly its outstanding feature, giving the tree a soft appearance. On young plants, the branches appear to twist and turn every which way.
Planting Zones, Sun, and Soil Requirements
Grow this tree in full sun and in a well-drained soil that is kept evenly moist. Chamaecyparis obtusa 'Gracilis' is not fussy when it comes to soil pH, but you should add compost to the soil to provide nutrients.
Uses in Landscaping, Warning
Use a pair of Slender Hinoki cypress trees in a symmetrical planting, as you would other evergreens popular for foundation plantings, such as dwarf Alberta spruce and columnar junipers. It can serve as a specimen plant in a Japanese garden.
Do not plant Hinoki cypress under any tree that sheds small leaves. As those small leaves fall, they will get trapped in the splayed foliage (which is quite dense). You will probably want to clean out this debris (since it is unsightly), adding to what landscaping chores you already have. For example, if you make the mistake of planting yours under a honey locust tree, you will be forever cleaning the fallen leaves of the latter out of the former. As minor as this consideration may sound, heeding this warning could save you quite a bit of inconvenience as the years go by.
Care: Pruning Hinoki Cypress Trees
You can prune (or simply pinch out, using your fingers) new growth to shape Chamaecyparis obtusa Gracilis and make it less susceptible to damage from snow and ice. But never make pruning cuts into the older branches (unless you wish to remove a whole branch in order to give your plant a better shape), since they will not generate any new growth.
Make sure that your plant is adequately supplied with water during the summer. Some of the foliage in the inner part of the plant will brown up over time, but you can minimize this problem by providing sufficient irrigation. When you do detect browning, pinch it out to keep your plant looking good. Unless there are a lot of brown leaves, there is nothing to worry about health-wise.
Nana Gracilis: The True Dwarf
You may scoff at calling a tree that will eventually reach 15 feet "semi-dwarf," but the fact is that Slender Hinoki cypress trees are extremely slow growers. This means that you will enjoy a tree that fits very reasonably within a small space for many years. But if you are planning for the long-term and have a very strict space requirement, buy 'Nana Gracilis' Hinoki cypress, instead. Nana Gracilis is the true dwarf. But even this true dwarf Hinoki cypress will reach 9 feet at maturity.
Origin of the Scientific Names for Slender and Dwarf Hinoki Cypress
Slender Hinoki cypress bears the scientific name of Chamaecyparis obtusa Gracilis; for the true dwarf Hinoki cypress, it is Chamaecyparis obtusa Nana Gracilis. Here is how those names break down so that you can remember them better:
- Chamaecyparis means "false cypress."
- Obtusa means blunt, referring to the appearance and feel of the needles.
- Gracilis is Latin for "slender."
- Nana is Latin for "dwarf."