It's not just its shell-shaped needle nests that make the mussel cypress an extremely exquisite plant for stylish front gardens or Japanese gardens. Because we are dealing here with a true noble tree that has even made a career in sacred building in its homeland.
What is a mussel cypress and what conditions does it prefer?
The mussel cypress (Chamaecyparis obtusa) is an evergreen coniferous tree from Japan. It is characterized by its columnar growth, shell-shaped needles and a characteristic, irregular crown structure. It prefers partially shaded locations and humus-rich, well-drained soil.
Origin
The other common German name for the mussel cypress is Hinoki false cypress - and this name already reflects a lot of its origins. That's right - the Chamaecyparis obtusa, as it is botanically called, comes of course from Japan. This is suggested not only by their Far Eastern-sounding name, but also by their artistic appearance, which is so typical of Japanese garden culture. From a German perspective, the mussel cypress was first described by the botanists P. F. von Siebold and J. G. Zuccarini in the middle of the 19th century.
In its homeland, the mussel cypress has much more than just a decorative garden use. Rather, it is also used for economic purposes because of its many other positive properties. For example, it contains valuable essential oils in wood and needles, from which the so-called hinoki oil is obtained. Their light wood, which smells wonderfully lemony, is also used in Japan as a noble raw material for sacred buildings such as temples and palaces, for shrines and also for table tennis bats.
In our case, the mussel cypress is mainly only used for ornamental gardens. Dwarf forms such as the small mussel cypress are particularly common in this country.
Origin at a glance:
- Muscle cypress comes from Japan
- First described by Germans in the mid-19th century
- Used in Japan not only as ornamental but also as valuable timber for sacred buildings
- Also for extracting Hinoki essential oil
- For us it's only for garden decoration, especially. a. the dwarf forms
Growth
The mussel cypress belongs to the cypress family and grows as an evergreen conifer. Its habit is characterized by an expansive columnar shape and an original, somewhat idiosyncratic crown structure due to the somewhat irregular branching. The crown is already attached to the ground and forms conical, wide shoots. These form a flat, fan-shaped shape, so that the eponymous wide, shell-shaped structures emerge at the ends.
Muscle cypresses can reach a height of up to 40 meters - however, the dwarf mussel cypresses, which are more common in this country, reach a maximum of 2.50 m high and around 1.5 m wide. They also grow very slowly. The trunk wood, which is light on the inside, is surrounded by a reddish-brown bark.
Growth characteristics in keywords:
- Columnar growth
- Protruding, irregularly structured crown that sits close to the ground
- Widely fanned, flat, shell-shaped shoot ends
- Growth heights up to 40 meters, with dwarf species only around 2.50 m high
leaves
The short needle leaves of the mussel cypress have a scale-like texture typical of cypresses and are located close to the ends of the shoots. These are spread out like a fan and seem to be pressed together - this is how the groups of leaves form their typical shell-like shape. The color of the leaves is a deep dark green.
Flowers and fruit
Basically, mussel cypresses naturally produce flowers and cone fruits for the purpose of propagation. The cones have a densely scaled, spherical appearance with a diameter of around 8 to 12 millimeters and sit like a nest in the ends of the shoots. However, the garden forms cultivated in this country are sterile - so they produce neither flowers nor cones.
Which location is suitable?
The mussel cypress prefers a partially shaded place. Too much sun can definitely damage it - but you should nevertheless make sure that it receives as much light as evenly as possible from all sides, otherwise it tends to grow irregularly.
Of course, this is not so easy, especially in the open field - with a southern orientation, where the conifers are lit on the sides from the west and east and in the south by trees or similar. However, if it is shaded, it can work well. When growing in containers, the risk of curly growth can of course be easily overcome by turning.
You shouldn't put the mussel cypress in a rock garden - even if its Japanese appearance would look good in a Far Eastern gravel bed. She doesn't like the dryness and high heat radiation of the stony bed surface at all.
Location requirements coming soon:
- More partially shaded, not too intensely sunny - risk of drought damage
- Make sure there is even light from all sides to prevent crooked growth
- Location in the rock garden not recommended
read more
What soil does the plant need?
The mussel cypress needs a permeable, fresh, moist and relatively humus-rich plant substrate. The pH value should be in the rather low, i.e. low-lime range. If you plant the mussel cypress outdoors and find clayey, heavy soil at the planned location, you should loosen and improve it well with sand and leaf compost. A drainage layer made of gravel is certainly not a bad idea either.
For the substrate in the pot, you should use high-quality, nutrient-rich potting soil, which you loosen with a portion of sand or coconut fiber and a little lava grit. The mussel cypress in the pot is also happy about a permanent nutrient supply with compost.
Earth claims at a glance:
- Permeable, humus, fresh-moist
- ph value rather low
- Loosen and improve heavy soil outdoors with sand and leaf compost, drainage layer made of gravel
- In the pot: good, nutrient-rich potting soil with some compost and sand
How do I transplant correctly?
Very few garden plants like being transplanted, especially if they are cultivated outdoors. Shell cypresses are no exception. Although they are very robust overall, they do not easily gain a foothold in a new location due to their slow growth. But if you really want to implement it, proceed as follows:
The time you should choose is autumn, when the conifer has completed its main vegetation phase but there are no severe frosts yet. Dig out the root ball as generously and carefully as possible and place the tree in the new planting hole, which you have provided with a base bed made of a gravel drainage layer and sandy compost soil. Then fill the hole with humus-rich soil, tamp it down well all around and water vigorously. A layer of mulch on the top of the planting area is recommended to protect the stressed root system from cold damage and drying out.
Do not prune to compensate for the inevitable root damage. With the slow-growing conifer, this is more weakening than strengthening.read more
Cut the mussel cypress correctly
In principle, topiary care is not necessary for the dwarf mussel cypresses cultivated in this country. They grow very slowly anyway and develop their characteristic structure best when left alone. In particular, radical pruning is not advisable for this type of conifer, as it does not sprout again from cuts in the old wood. Younger specimens can still be shortened slightly in external areas in the spring if their shape does not develop as desired. But never cut back more than about 3 cm.read more
Bonsai
Nevertheless, mini mussel cypresses, like many other types of cypress, are also suitable for bonsai cultivation in the garden. An artistically trained mussel cypress can be very decorative, especially in a front garden. When designing, it is particularly recommended to work with accurate foliage trimming. Branches that are stringently and regularly wired are attractive when the shapely needles are placed in precisely contoured bushes at the ends of the branches.
When wiring the trunk and branches, you should make sure to remove the wires from May when thickness growth begins. This way you avoid wiring traces or ingrowths. You should fertilize a bonsai mussel cypress regularly during the growth phase.read more
Propagate mussel cypress
Propagate a mussel cypress tree is not entirely trivial. Due to its generally slow growth, it is also not very prolific when propagated vegetatively. Nevertheless, the cutting method is actually the only method of choice for private gardeners. You won't get seeds from the sterile garden forms anyway.
You generally have a higher chance of growth with younger mother plants that are still full of juice. Things can get very complicated with older copies. In late summer, use an angled cut to cut out as fresh a shoot as possible, about 15 centimeters long, from the upper part of the crown. Defoliate except for one upper pair of leaves. It is strongly recommended to dip the cut surface in rooting powder (€8.00 on Amazon).
Place the prepared cutting in a planting bowl with humus-rich potting soil. The chances of growth are highest if you have a (mini) greenhouse available in which you can offer the cuttings an evenly warm, moist and protected climate. It should receive plenty of light, but be protected from direct sunlight.
If the cutting forms new shoots, you - or HE - have made it and have grown. Continue cultivating it indoors or in the greenhouse over the winter. The young mussel cypress should only be planted outdoors after its first year of life.read more
Diseases
The mussel cypress is very sensitive to waterlogging. If your planting soil is not permeable and humid enough, it can be attacked by the fungus Phytphthora cinnamomi, which causes the roots to rot and the plant to die. When planting, make sure there is sufficient drainage and good loosening of heavy soils with coarse-grain sand.
The mussel cypress can also be affected by the shoot death that often occurs in conifers. You can recognize this disease by dying shoots and black dots in the affected areas. However, shoot death can be easily controlled with a fungicide.read more
Pests
The mussel cypress can occasionally be attacked by scale insects or spider mites.
Scale insects
You can recognize scale insects, among other things, by the honeydew that they secrete when they suck on the juicy shoots of the mussel cypress. If you are not careful, sooty mold fungi can also nest under the honeydew.
If the scale insect infestation is still relatively weak, first attack the animals mechanically by removing them from the plant with a damp cloth or a toothbrush. You can then treat the mussel cypress with a decoction of nettles or tansy. If the infestation is more advanced, use oil-based preparations that will suffocate the lice.
Spider mites
These parasites are actually primarily houseplant pests. But they don't stop at the tasty shoots of mussel cypresses. They easily reveal themselves through the fine webs with which they cover the branches and leaves of the host plant. With a structurally robust plant like the mussel cypress, you can work with a strong jet of water from the garden hose. Spray them thoroughly, if necessary several times. This should normally get the infestation under control.
If populations are too stubborn, you may have to cut off the affected parts of the plant and dispose of them as thoroughly as possible, ideally burning them. The use of predatory mites, for example in the form of the gall midge Feltiella acarisuga, is particularly ecologically sensible. However, their use on planted mussel cypresses is only possible in summer when warm temperatures above 20°C prevail. Only then will the beneficial insects have suitable living conditions. There should also be high humidity.
Varieties
The dwarf variety 'Nana Gracilis' is most commonly found in specialist shops. But there are also a few other cultivated forms that differ from each other primarily in their foliage color and sometimes also in their growth habit.
Chamaecyparis obtusa ‘Nana Gracilis’
In German, the variety is simply called dwarf mussel cypress. Its growth is indeed dwarf - it reaches a maximum height of 3 meters and a width of around 2 meters. It shows a compact, well-branched, initially spherical and later more conical growth. The horizontally extending branches form dense needle bushes. Due to its compact, neat appearance, the variety is also suitable for grave planting.
Chamaecyparis obtusa ‘Lycopodioides’
This variety is also called coral cypress in German. This name already indicates its special nature: In fact, it develops coral-shaped, twisted shoots, which give it a much more delicate appearance than most of its conspecifics. The needle color is a cool blue-green. In terms of height and width, it is about the same size as the Nana Gracilis variety.
Chamaecyparis obtusa ‘Fernspray Gold’
This variety also says it all: It is characterized by a golden yellow needle color, which gives it a fresh, delicate character. Its growth is also exceptional: it forms gently curved branches extending from the ground with tapered tips and fine needles. This makes it similar to a fern. Fernspray Gold is very slow-growing.
Chamaecyparis obtusa ‘Aurora’
The Aurora variety is also characterized by yellowish coniferous leaves and can therefore create a particularly attractive color accent, especially in combination with dark-leaved conifers. As with the Nana Gracilis, it grows quite bushy and compact, but is significantly smaller at a maximum height of one meter. Its width reaches around 60 cm.
Chamaecyparis obtusa ‘Pygmaea’
This variety shows a rather spherical growth and, at around 3.50 meters high, is slightly larger than the other dwarf varieties. Its coniferous leaves have a fresh green color that turns brownish in autumn.
