Castor Bean Plant

Some plants, while they need roles to play in your landscaping, are hardly conversation pieces. for instance , catmint are often a superb ground cover, but rarely will a visitor walk onto someone’s landscape and remark, “Wow, check out that catmint!” it’s not designed to evoke such a response—instead, its purpose is to play a supporting role. oilseed plants, on the opposite hand, have star power.

What gives oilseed plants their star power? Let’s consider the three T’s: tall, toxic, and tropical. it’s because castor beans possess these three qualities (and more) that they’re such interesting plants. Native to Africa and therefore the Middle East oilseed plants grow quickly, adding between 6 and 10 feet per season and featuring star-shaped leaves with vibrant red seeds. It are often planted straight into the garden in late spring or started from seed indoors about six to eight weeks before the last frost of the season.

castor bean plant
Botanical Name Ricinus communis
Common Name Castor bean
Plant Type Herbaceous perennial
Mature Size 6–10 ft. tall, 2–4 ft. wide
Sun Exposure Full sun
Soil Type Moist but well-drained, rich
Soil pH Neutral to acidic
Bloom Time Summer, fall
Flower Color Greenish-yellow
Hardiness Zones 9–11 (USDA)
Native Area Africa, Middle East
Toxicity Toxic to humans and animals
castor bean plant foliage

Castor Bean Plant Care

Castor bean plants are typically grown during the summer in most environments and can quickly reach sprawling heights, making them an eye-catcher in your landscape or an excellent option for a living privacy fence if grown together. However, height is simply one attribute that creates oilseed plants stand call at your landscape. Their coarsely textured leaves create dramatic textural contrasts when placed alongside plants that have smaller leaves.

While the flowers on the oilseed plant are insignificant, the red seed capsules covered in spines do possess ornamental value. When these pods dry, they explode, turning the seeds that had been trapped within into projectiles. Even the seeds themselves are attractive, sporting an endless number of colours and patterns. it’s perhaps the looks of those seeds that give the plant its genus name, Ricinus, which translates to “tick” in Latin.

Many people are conversant in the very fact that purgative , an old-time laxative and purgative, is pressed from oilseed seeds. Additionally, some gardeners use castor beans in companion planting to function mole repellents. That being said, castor beans aren’t true beans—that’s just a nickname. The plants belong to the Euphorbiaceae family, which makes them relatives of poinsettia plants and Euphorbia amygdaloides . Since castor beans are tall, slim plants with large leaves that act like sails within the wind, make certain to stake them unless you’ve located them during a spot sheltered from high winds. Generally, the plants haven’t any serious issues with pests or diseases.


Castor bean plants like full light and will be planted somewhere in your landscape where they get a minimum of eight hours of sunlight each day . Avoid putting the plant below any towering trees, which may impact the quantity of sunshine it can get. Additionally, confine mind that the more sunlight your plant gets, the fuller and more productive it’ll be.


Soil that’s rich and moist will produce the simplest results for your oilseed plant. The mixture should be nutrient-dense and hold moisture well, but shouldn’t be boggy or easily waterlogged. If your intended planting zone isn’t known for its soil, you’ll amend the mixture with some organic interest increase the nutrient density.


Castor bean plants like soil that’s consistently moist, but you ought to lookout to not overwater them. Generally, the plant likes around 1 inch of water per week, either from rainfall or manual watering. confine mind, that quantity may have to extend if you experience drought-like conditions or are having an especially hot summer.

Temperature and Humidity

True to their tropical nature, oilseed plants like warm temperatures and above-average humidity levels. If planted within the right USDA hardiness zones, your plant should be quite happy. As a rule of thumb, oilseed plants need soil temperatures of fifty degrees Fahrenheit to 64 degrees Fahrenheit to be planted outside and can grow and thrive best in an environment that ranges from 68 degrees to 80 degrees Fahrenheit consistently.


For best success, feed your oilseed plant once a month with a general, all-purpose fertilizer.

Is oilseed Plant Toxic?

A poisonous plant altogether its parts, castor bean’s namesake “beans” (i.e., the seeds) are especially toxic. In fact, they’re the source of the infamous poison, ricin. Their toxicity are often problematic for young children and curious pets, so keep this in mind when considering where (if whether) to plant this eye-catching specimen. If you continue to want to grow oilseed plants, you’ll lessen their danger by isolating the flowers and removing them, thereby preventing seed formation.

Death from ricin poisoning can occur between 36 and 72 hours of exposure, so time is of the essence. If you notice any of the below symptoms of poisoning, contact the right emergency services directly .

Symptoms of Poisoning in Humans

  • Vomiting
  • Diarrhea
  • Dehydration
  • Difficulty breathing
  • Tightness in chest
  • Fever
  • Low vital sign
  • Seizures
  • Blood in urine or stool
  • Pain of the skin or eyes
  • Kidney, liver, or spleen failure

Symptoms of Poisoning in Animals

  • Abdominal pain
  • Bloody diarrhea
  • Dehydration
  • Excessive drooling
  • Loss of appetite
  • Fever
  • Mouth pain
  • Sudden collapse
  • Shaking or trembling
  • Vomiting
  • Weakness

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