Poisonous plants can be found growing in the wild in all parts of California. They are often used by gardeners because they are beautiful and stand out in a landscape. Take care to plant poisonous plants where children and pets do not have access to them. Clean up all the debris that falls to the ground. Gardeners have to decide if the extra work involved in growing poisonous plants is worth the concern.
The castor bean (Ricinus communis) is also called the castor oil plant, palma Christi and wonder tree. All parts of the castor bean plant are poisonous and have caused deaths in children. The plant can grow as a shrub or tree. It grows up to 40 feet tall and 15 feet wide and produces purple or red-green palm-like leaves that grow from 12 to 30 inches across. The green-yellow flowers grow in clusters on a spike, with the female flowers at the top. The female flowers produce egg-shaped, red-brown, 1-inch long capsules, each of which contains three seeds. Plant castor bean plants in full sun and moist soil. The plant grows quickly and fills in an empty space very quickly.
The camphor tree (Cinnamomum camphora) is also known as camphor laurel, shiu leaf, gum camphor and laurel camphor. Camphor is toxic and stimulates the central nervous system, affecting respiration and/or causing convulsions. The tree is a broad-leaf evergreen that grows from 50 to 150 feet tall with a spread twice as wide and a trunk that can be 15 feet in diameter. The tree produces shiny, green, oval leaves that are a rusty burgundy when young with three yellow veins that grow from 1 to 4 inches long. The flowers appear in the spring, are small, cream-colored and grow on 3-inch long stalks. The fruit follows the flowers, is about the size of a pea and starts out red, turning to black when it ripens. Plant the camphor tree in full sun or partial shade and in a fertile, sandy soil.
Sago palm (Cycas revoluta) is also known as Japanese sago palm and funeral palm. All parts of the plant are toxic. The tree grows from 10 to 12 feet tall, but it can take up to 50 years to get that high. The plant produces leaves that grow from 4 to 5 feet long and 9 inches wide. The flower will be either a male yellow rod-shaped cone that grows from 12 to 18 inches long or a female that is yellow and globe-shaped that produces bright orange seeds. Plant the sago palm in full sun, partial shade or full shade and in a soil that is sandy and fast draining. The tree will not survive in a wet soil. Because it is so slow growing, the sago palm is a good choice for a house plant.