Castor aralia (Kalopanax septemlobus)

One of the truly stunning ornamental to shade trees for northern areas. This tree produces large starburst like panicles of small white flowers in summer each group 12-24 inches (30-60 cm) across that can cover the tree. While each flower is small the overall look can be stunning. The flowers are followed by blue black berries in the same large clusters these appear just when the leaves turn a stunning bright yellow making the contrast amazing so the tree looks like it was decorated for Christmas.
Once established needs little maintenance hardy to zone 4 but does not do well in warm humid south east US. Not very drought tolerant but the young shoots and leaves are harvested in spring as a seasonal vegetable which is much prized in Korea and Japan.

A stunning large ornamental tree that comes into its best during the autumn fall period. It produces large flat palmate leaves ?? inches (15-40cm) across that are mid to deep green with finely serrated edges. Leaves have anywhere from 3-7 lobes with 7 being most common. Most trees have triangular pointed lobes with fine points but some have much deeper cut leaves almost to the central vein. In midsummer it produces large panicles on the end of each branch. These consist of long star or firework burst of white to yellow stems that sometime branch half way down. The end of each stem holds a small globe of tiny white star shaped flowers. The whole panicle can be 12-24 inches (30-60 cm) across and with one on each branch the tree can be quite stunning. The flowers are followed by small globular bluish black fruits each (4-6 mm) across creating large blue black firework bursts on the tree. This happens at the same time as the leaves turn a beautiful bright yellow making the blue black fruits stand out and appear like a decorated Christmas tree. It can be truly stunning. The bark of the tree changed dramatically as the tree grows. Small young branches are covered in large sharp thorns but these drop off as the branches grow larger and the trunk has none at all.

Seeds are a little fussy before they will germinate. first they require a period of warm, as they would have in a normal fall. This must be followed by a period of cold moist stratification for 2-3 months. All our seeds go through a period of warm moist then we store then in cold until they are sent to you. This means that only about 60 days of moist stratification is required. Our Stratification instructions provide a variety of methods so you can choose the one that is best for your needs.
If using the refridgerator to complete your moist stratification we recommend using the Egg Box Method to keep seeds separated, minimize the space used in the refridgerator and keep the seeds safe and unharmed.
Once seeds have been stratified plant in small pots or cell trays to ensure that germinating seedlings do not disturb their still slumbering brothers and sisters when they need to be transplanted. Place in warm location no more than 74 F (24C) in medium light not in full sun and not directly under a grow light. Seedlings need medium light as they are used to growing on shaded forest floors. Keep soil moist but not wet. Small trees grow slowly to begin with as they develop their roots first. Once large enough they can be placed outside in a shaded area to grow. DO NOT PUT IN FULL SUN.
Depending on your location trees may not be large enough to be transplanted out the first year. If so ensure that pots are placed in a location such as a garage for the winter months where pots cannot freeze solid. While trees can withstand freezing in the ground they dont do as well in frozen pots above the ground. If necessary pots can always be sunk into the ground for the winter months. Again not in full sun.

This is a very hardy tree which can tolerate temperatures down to -31 F (-35C). It is zoned from 4-8 (USDA). For this reason it does not do well in the warm humid south eastern portion of the country but thrives in almost all parts of the northern states.
Light. while mature trees do well in full sun in colder zones 7 and warmer partial shade is also possible. In all cases small seedlings do not tolerate full sun. Young trees have evolved to grow on the forest floor so do very poorly in full sun. Shade should be provided until the trees are at least 36 inches (1m) tall although this may vary, in colder zones with less light should be able to expose trees to full sun at smaller sizes while those in warmer zones 7-8 most commonly will need to shade trees for longer.
Space. Trees always need space and this one is especially important if used as an ornamental as its shape will not fully develop if crowded by other trees. Grown alone as a Specimen tree it can be stunning and very remarkable. This is especially important in warmer zones where airflow to allow cooling breezes will be especially important.
Soil. Prefers deep fertile soil that will retain moisture but not one that is waterlogged. If you have a poorer soil create a larger hole before planting and mix in a large amount of well rotted compost before planting. It can tolerate a wide range of pH but some mulch to help mediate this would be beneficial especially in poor soils.
Water. Ensure that small trees are watered regularly. This is not a drought tolerant tree and will need to be tended during periods of drought or growth will be stunted. Very prolonged drought could kill the tree.
Mulching. All young trees will benefit from mulching to keep the soil around them moist. Ensure that mulch is not piled against the trunk, keep it at least 6 inches (15cm) away to prevent mold, and rodent damage. Protect trunks from mower damage.

Flowers are high in nectar and are popular with many pollinating insects. However since they usually high in the trees its hard to appreciate them.

In Korea and Japan the young shoots and leaves are harvested in spring as a seasonal vegetable which is much prized. The foliage is typically blanched (boiled briefly) to remove bitterness, then used in salads, soups, namul, or fried as tempura. Their flavor is reportedly spicy and aromatic (somewhat like a mix of celery and carrot).

While not as yet commonly used in Western Herbalism Castor Aralia has long been used in Eastern Medicine. The inner bark is most commonly used but the roots are sometimes employed. Most commonly used as a decoction it is used to treat inflammatory conditions most commonly chronic hepatitis and liver disorders but also rheumatism, neuralgia, pleurisy (wind-damp edema). It is reported to relieve joint and muscle pain (Arthritis, lumbago), improve circulation, and act as a general tonic. Leaves are also used as a tea for digestive issues.

The wood is very strong and fine-grained. It has been used for bentwood furniture, carving, and interior application.
The bark and leaves contain substances (saponins, phenolics) with insecticidal or acaricidal properties. Folk preparations use the mashed bark/leaf as a spray or ointment to repel or kill pests such as termites, lice and ants.

tree aralia, prickly castor-oil tree, ink tree, and harigiri

synonyms: Kalopanax pictus, Acanthopanax ricinifolium, Acer pictum