Botanical name: Fatsia japonica
Castor Oil Plant also called Japanese Aralia, Paperplant or Glossy-leaf Paper Plant is a popular houseplant with a tough constitution. It is native to the tropical regions of southern Japan, southern Korea and Taiwan. The botanical name "Fatsia" is an approximation of the Japanese word for 'eight' in reference to the eight leaf lobes. The leaves are large, deeply lobed and leathery in texture. It is an excellent stand alone plant, growing to a height of 4 ft or more. The flowers rarely appear under room conditions. The plant is extremely durable and can withstand a wide range of conditions and has been shown to effectively remove formaldehyde gas from indoor air.
Several cultivars of Castor Oil Plant have been developed. One of the recognized cultivars is Fatsia japonica Variegata commonly called Spider's Web or Spider White which bears variegated leaves.
Bright light to light semi-shade is ideal for Castor Oil Plant. An east- or west-facing window is ideal for this plant. Learn more on how to ensure your plant receives the correct light in this guide on understanding light for houseplants.
Water Castor Oil Plant thoroughly during the growing period and allow the top 2 in. of soil to dry out between waterings. Reduce watering in the cold months. Avoid waterlogging as it can lead to root-rot disease and eventual death of the plant. Learn more on how to water houseplants.
Average warmth with a minumum of 100C is ideal for Castor Oil Plant. The plant prefers a relatively warm temperature during the growing season followed by a relatively cold season. Find out more on temperature for houseplants.
Castor Oil Plant has no need for high humidity. Average room humidity is ideal for this plant though it can withstand dry air. Mist the leaves frequently and clean them by damp-wiping with a soft cloth.
Feed Castor Oil Plant with a balanced water-soluble fertilizer once every month during the growing season. Withhold feeding in the cold season as growth is minimal and feeding at this time can lead to fertilizer burn. Find out more on feeding houseplants.
Repot the young Castor Oil Plants annually and the mature plants every two years. The best time to repot is at the beginning of the growing period. Use a pot 1 size larger and free-draining soil that is rich in organic matter. Ensure the pot has a drainage hole to avoid waterlogging which can lead to root-rot.
Prune Castor Oil Plant at the beginning of the growing season. Cut back the foliage a few inches above the soil level to rejuvenate growth and achieve a more compact and bushy plant. The foliage can be used to take stem cuttings for propagation of new plants. Learn more on how to prune houseplants.
Propagation of Castor Oil Plant can be done by seeds or by stem-tip cuttings. Rarely will the plant flower or produce seeds when grown indoors. Propagation by stem-tip cuttings therefore becomes the best option. Take a stem-tip cutting about 3 in. long and bearing at least two leaves. Dip the cut end in a rooting hormone and stick the cutting in moist rooting soil. Place the set up in a warm humid place until new growth appears. Once the new plant has established, continue with the normal routine care.
The causes are either too dry air or the plant has been exposed to too hot sunshine. Mist the leaves frequently if the air is to dry or set the pot on a wet pebble tray to raise humidity. Shield the plant from hot sun or move it a shadier spot.
Underwatering is the cause. Water Castor Oil Plant thoroughly during the hot season and allow the top 2 in. of soil to dry out between waterings. Never allow the soil to become completely dry. Learn more on how to water houseplants.
Waterlogging is the cause if leaves are wilted and soft. Ensure the soil is free-draining, the pot has a drainage hole and allow the soil to dry out between waterings. If leaves are brittle, too much heat is the reason; ensure that an average room tempearture is maintained, that is, a temperature that is comfortable for a human being is ideal for Castor Oil Plant.
Castor Oil Plant (Fatsia japonica) produces a sticky and resinous sap which has been found to cause contact dermatitis in sensitive skin.