Castor Bean

Sow castor bean from seed either outdoors directly in the soil after all danger of frost has passed or indoors six to eight weeks before your region's last average frost date.

Step2

Soak the seed for 24 hours in warm water, then plant it 1 inch deep.

Step3

Plant outdoors in full sun. Castor bean needs rich, deep, well-drained soil, so it's a good idea to work in a spadeful or two of compost to a depth of 2 feet or more.

Step4

Keep soil evenly moist. Mulching is a good idea.

Step5

Trim faded flowers to promote longer bloom.

Step6

Fertilize every four to six weeks or work in a slow-release fertilizer (or plenty of compost) at planting time.

Step7

Stake if needed. Castor bean grows 3 to 6 feet tall, depending on growing conditions, and 2 to 4 feet wide.

Step8

Tear out and discard plants after frost fells them in fall in zones 2 to 7 of the USDA Plant Hardiness Zone Map (see thegardenhelper.com/hardiness.htm). In zones 8 to 11, castor bean can be treated as a perennial. Cut back each fall.