Kalopanax Species, Castor Aralia, Prickly Castor Oil Tree, Tree Aralia

Kalopanaxseptemlobus

Genus
Kalopanax (kal-OH-pan-aks)
Synonym
Acanthopanax septemlobus
Acer septemlobum
Sun Exposure
Full Sun
Foliage
Grown for foliage
Deciduous
Height
over 40 ft. (12 m)
Spacing
over 40 ft. (12 m)
Hardiness
USDA Zone 4a: to -34.4 °C (-30 °F)
USDA Zone 4b: to -31.6 °C (-25 °F)
USDA Zone 5a: to -28.8 °C (-20 °F)
USDA Zone 5b: to -26.1 °C (-15 °F)
USDA Zone 6a: to -23.3 °C (-10 °F)
USDA Zone 6b: to -20.5 °C (-5 °F)
USDA Zone 7a: to -17.7 °C (0 °F)
USDA Zone 7b: to -14.9 °C (5 °F)
USDA Zone 8a: to -12.2 °C (10 °F)
USDA Zone 8b: to -9.4 °C (15 °F)
Danger
Parts of plant are poisonous if ingested
Bloom Color
White/Near White
Bloom Time
Mid Summer
Other Details
Category
Trees
Water Requirements
Average Water Needs; Water regularly; do not overwater
Foliage Color
Where to Grow
Bloom Characteristics
This plant is attractive to bees, butterflies and/or birds
Bloom Size
Other details
Soil pH requirements
5.6 to 6.0 (acidic)
6.1 to 6.5 (mildly acidic)
6.6 to 7.5 (neutral)
7.6 to 7.8 (mildly alkaline)
7.9 to 8.5 (alkaline)
Patent Information
Non-patented
Propagation Methods
From seed; direct sow outdoors in fall
From seed; winter sow in vented containers, coldframe or unheated greenhouse
From seed; stratify if sowing indoors
Seed Collecting
Properly cleaned, seed can be successfully stored
Regional

This plant is said to grow outdoors in the following regions:

Palmetto, Georgia

Evanston, Illinois

Maple Park, Illinois

Monticello, Illinois

Roslindale, Massachusetts

Helena, Montana

Fairport, New York

Lyndonville, New York

Medina, New York

Syracuse, New York

Cottage Grove, Oregon

New Kensington, Pennsylvania

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Gardener's Notes:

3
positives
4
neutrals
1
negative
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P
Hamden, CT | May 2023 | neutral

I love this plant, but I would NOT recommend planting it. Let me explain: Kalopanax septemlobus, or castor aralia, is the only large tre...Read More

R
Niles, OH (Zone 6a) | May 2014 | positive

This is a very attractive, unique tree which provides a tropical feel but is winter hardy. It is attractive throughout the year with lush...Read More

C
ROSLINDALE, MA | January 2014 | negative

I live in Boston near the Arnold Arboretum, where this tree produces tremendous numbers of seedlings.

I have observed thi...Read More

B
| November 2012 | neutral

Hi all

I recieved my seeds today that i orderd from the USA. I live in the UK and need some help with germination of the s...Read More

M
Evanston, IL | May 2011 | neutral

Three of these have popped up in my yard uninvited, and it looks like they germinated over a two-year period. I've seen a couple of other...Read More

D
Medina, NY | April 2011 | positive

I planted three seeds that I got from Smiths Pond in Lyndonville, NY from a mature and lovely tree which is beside the pond and near Plat...Read More

L
L
Denison, IA (Zone 5b) | November 2006 | positive

Bought a little plant last year and it died to the ground. It came back this year. But I gave it a positive because I think it'll becom...Read More

P
Syracuse, NY | April 2005 | neutral

This tree is not grown commonly in the Syracuse area. Two specimens at Pass Arboretum reputed to be the only K pictus in the city. Both...Read More

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