Long time readers here will, I'm sure, immediately recognize one of our annual behemoths of the garden, Ricinus communis 'Zanzibariensis.' We plant a few Castors every year because we just love their lush tropical look and appreciate how easy they are and how quickly they grow! This particular one was planted from seed a little over a month ago and look at it (as of 8-16-08) now! At this point, it's surpassed Fernymoss' head (he's 6 ft tall), and with the regular feedings of fish emulsion he's been giving it, with a little luck and plenty of sun it should get pretty tall and perhaps even bloom before frost. (If you'd like to see just how big it got last year, click on the name in the labels below the post.)
The one we pampered and fed last year topped out at about 14 ft tall by October, bloomed, and put on tons of seeds, from which this one is growing (as well as the smaller one near it). Though we were really late getting these seeds in (sheesh, July!) this guy has been really happy keeping the new peonies (who are fading now) company in the NE corner of our backyard. And no matter where we have them in the yard, they are always eye catchers for passersby, who sometimes stop to ask what on earth it is, marveling that something so obviously tropical is growing in the middle of the city in summer! Of course, they're only an annual here and usually have been killed off around the time Halloween comes around, but if you look at my post from last Halloween, it hadn't yet had the killing frost and was a great spot to pose in my Halloween garb.
Ok, here's my usual disclaimer about these plants ... yes, they are the source of Castor Bean Oil (the dreaded bane of constipated kids everywhere when I was little). I'm not exactly clear how, during the oil extraction process, they go from being deadly toxic to just an oil used a purgative, so to speak. But for all practical purposes, anyone growing them should be aware that every part of this plant is extremely toxic, so if you have children or pets who are prone to munching on plants, it's probably not a good idea to have them around unless everyone understands just how toxic they are.
I recall a news story from a few months ago about a man in Las Vegas who tried to commit suicide by eating some seeds, and people investigating the case were flipping out about possible contamination to the room in the hotel where he made his attempt. I thought all that was a bit silly, because if you just practice common sense with them, the chances of experiencing such effects are very slim and in over 10 years of growing them, we've never had any problems. The seeds, however, are perhaps the most toxic part of the plant, so they should be stored well out of the reach of anyone or any pets who might find them and think they'd make a good snack. I read in one article that it only would take about 5-6 seeds to kill a human if they are chewed up and ingested ... so a word to the wise.
Having given that disclaimer, they make great architectural specimens in the sunny garden, and their only drawback is having to saw them down after it has died from a freeze. We usually just clean up the dead leaves and leave it in the ground over the winter and saw it down in the spring when it has started to decompose a bit. We also plant another variety, 'Carmencita Rose,' which is a "dwarf" variety that only reaches about 8 ft tall (lol). This year we just popped a few seeds in a huge pot out front and are growing them that way this year, just so they get big enough to draw attention, since we didn't get them in early enough to really place them strategically. 'Carmencita' is a really stunning shade of bronzy red that positively glows in the sun, and is definitely a variety worth trying if you want to try your hand at growing these tropical giants.