Castor bean

About

A fast-growing tropical plant grown for its bold leaves that has escaped in warm states. Its seeds contain ricin, one of the most dangerous plant poisons, so it doesn't belong where children or pets play.

Also called castorbean, castor oil plant, mole bean plant, African wonder tree

How to identify it

Look for

Huge, star-shaped leaves with 5 to 11 pointed lobes can be 1 to 2½ feet across, on red, green or purple stems. It grows 6 to 15 feet in a single season, and more in frost-free areas where it lives for years. Spiny red or green seed pods hold shiny, mottled seeds that look like swollen ticks.

Where it grows

Disturbed ground, roadsides, old fields, rocky slopes and gardens in full sun, mainly in warm, frost-free areas.

When

Grows through the warm season, flowers from summer into fall, and ripens seed pods from late summer on; it dies with frost in cold areas.

How it spreads

Spreads by seed that sprouts readily near parent plants.

Most common in

Where it is regulated

The California Invasive Plant Council lists it as invasive (limited), and Florida's invasive species council ranks it Category II invasive.

What to do, gentlest first

Protect yourself first. Weed killers are a last step; always read and follow the label.

1. Don't plant it Prevent

   Choose a safer bold-leaved plant, especially where children, pets or livestock roam.

   Never keep or share the seeds.

2. Pull seedlings and cut off seed spikes By hand

   Pull young plants while small. On larger plants, cut off the flower spikes before pods form, then cut or dig out the plant.

   Wear gloves and bag pods and seeds for the trash; don't compost them.

Uses, wildlife and pets

Pets

Toxic to dogs, cats and horses (ASPCA); the seeds are the biggest risk, and as little as an ounce can kill.