The Castor Bean Plant, Ricinus communis, what a fascinating plant. I wouldn’t exactly call this “rare” but it certainly isn’t wide spread up here in Victoria, B.C. The Victoria Parks department have a knack for using strange tropicals but other then that I haven’t encountered any amateur gardeners using it in their borders. Being an avid nursery junkie, it’s also quite rare to see these for sale in the stores. The Castor Bean has gorgeous tropical foliage and unusual spiky poisonous seed pods. I’ve been in love with this plant since the first day I spotted it at a botanical garden in Gottingen, Germany. Shortly after seeing it at the gardens I spotted a small package of seeds at a German garden center and “accidently” smuggled them back to Canada.
The Castor Bean plant is native to Africa but can be found throughout the world due to human admiration. Ricinus communis dies at the first sign of frost but in the southern states, Mexico and beyond the plant tends to naturalize easily and sometimes even become a invasive nuisance. Ever clear a patch of 40 foot castor beans out of your ditch, oh what a life that would be. Due it’s deadly nature it’s no surprise to me to learn that it’s in the spurge family (Euphorbiaceae) and is related other menacing plants. Besides being cultivated for it’s striking good looks, Ricinus communis is also grown for it’s versatile Castor Oil. It seems to be used for everything from folk medicine (laxatives etc) to adhesives, inks and dyes. Fascinating!
I’ve had very few problems with this plant. The spider mites seem to enjoy it but by no means kills it, only slows it down. Another time I spotted some little green cabbage catapillars on them, but I suspect they wouldn’t be long for this world. Due to the fact that the entire plant carries high levels Ricin (A deadly poisonous chemical read more here) pests generally stay clear of this plant. Castor beans like regular watering and fertilization and will do best in full sun.
How to Over Winter Your Castor Bean
I would say the main cause of death to these plants in Victoria would be frost. In a panic last October I searched the internet seeking advice on how to overwinter these mindblowing specimens. At the time my stock was rather small and I considered bringing them indoors. Having had entirely too much to bring inside already I opted to take a different route and brought them into the greenhouses at work. While they lost all of their leaves, come mid March/April they started to flush out again and this year they were even more incredible. I still have the original 2 specimens that I grew from the seeds from Germany (1 red leafed and 1 green leafed) and both are loving life. Castor beans DO NOT have to be considered annuals in the north, just make sure to keep them in a greenhouse with plenty of sun, no frost, and lowered watering. Any stories of keeping them alive in a basement would also be interesting to hear, contact me and share a tale.
Needless to say, Ricinus communis is a great plant to add the collection and it will be a very sad day when the frost finally claims these beauties. My current specimen 2 years later is nearly 8 feet tall and in full bud, hopefully I’ll get some of those wacked out seeds I saw so many years ago.
Unusual Castor Bean Planting?
Look at how similar these plants look. Fatsia japonica, Tetrapanax papyriferus & Ricinus Comunis. Your homework today is to create a mind blowing planting of the three, and take a photo to share with the world. Due date, next season!