by Elizabeth Spence
I’ll tell you why I never wanted to grow rhubarb. It makes me ill. Whether it’s in a sauce, in a pie or crumble, roasted or in a salad – it makes me ill.
There are several unpleasant substances in rhubarb. One is the anthraquinone glycosides which are responsible for abdominal discomfort. Another is calcium oxalate potentially leading to kidney damage and kidney stones. These are found in the leaves and the stalks.
The concentration of the oxalate in the leaves is very high, which is why they are considered poisonous. There is less in the stalks, and by cooking them you get rid of about 70% of it, but there is still some there. I suspect I’m just particularly sensitive to these substances, and so I just don’t touch the stuff.
So why do I grow it? Well, a few years ago, a friend was dividing hers and gave me large clump.
“Thank you very much,” I said.
“Aren’t friends kind,” I thought
I planted it in an area where I was sort of planning to have my flower beds at the house I was just starting to renovate, just to show my friend that I was appreciative more than anything else. The ground was basically gravel, weeds and some original soil. I didn’t hold out much hope for the poor plant. (I didn’t really care).
But do you know what? After a while, it took off at the speed of light. It sprang to vigorous life! Perhaps it was the excellent drainage. I don’t know.
I never did much about it – I just left it there to its own devices, and then one day, as I was examining it during one of my early garden walkabouts, I thought,
“What a magnificent plant!”
There are, of course other big-leaved plants available for the garden. I already had my own Japanese butterbur, Petasites japonica, (“petasites” means hat-like”).
The flowers are the first to appear in the spring before anything else which is quite a joy.
The leaves are about three to four-feet across and the whole clump stands almost six-feet high. So it is very impressive indeed.
I then thought about some of the other huge-leaved plants that are sold for the garden in our area and which I had grown at one time or another.
There’s Darmera peltata or Indian rhubarb. It has pretty pink flowers in the spring and its stalks are also edible.
And then there’s Astilboides tabularis or Shield-leaf Rogersia. It’s called Astilboides because the flowers look like astilbes.
Next are the Rogersias. There are various types and colours of leaves and flowers.
Finally, there are the ginormous Gunneras, which are definitely not hardy here, although you sometimes see them advertised. Don’t bother with these. They won’t survive our winters.
All these plants require damp, if not boggy soil and dappled shade at the least. If they don’t get these, they will wilt and be scorched by the sun. They also don’t do well in windy spots since the leaves just get shredded and they soon start to look quite tatty. They do have very specific needs.
The Petasites in particular is a garden thug which, under the right conditions, will spread like wildfire. It’s considered the equal of goutweed in that matter. It needs a lot of watching to keep it under control – as I know! In fact, it is now officially classed as an “invasive.”
I have had mixed results with the Rogersias, Astilboides and Darmeras I have grown over the years. It was a bit of a struggle with some of them, and I think a few just hated me: whatever I did, they just quickly turned up their toes and died. Others did survive, but I could sense the spite directed at me when I passed them as they just slowly languished away. One or two did fairly well, but didn’t last very long.
Apart from me possibly not keeping my wits about me, one of the problems, I think, is the zoning. Some are generally classed as Zone 5, which is what we are on the North Shore, but upon investigation, this is U.S. Zone 5 which is our zone 6. (See our article on zoning which goes into this problem). It means that our winters are probably too severe for some of them.
There was none of this with my common and garden rhubarb which thrived on neglect. It’s basically as tough as nails – hardy down to zone 3 to start with, and it doesn’t mind full sun. The leaves are just as big as the other plants, and the flower spikes are exquisitely dramatic!
I do absolutely nothing to it – no fertilizer, no manure, no nothing. It’s still growing in the rough ground it started in.
It isn’t often that we see the rhubarb’s flowers because we are constantly told to remove them as soon as they appear. The received wisdom is that the plant puts so much effort into producing the flowers that its energy will be diverted from the stalks and leaves and the harvest will be much smaller.
Apart from leaving them on the plant to be admired, there is more you can do with mature rhubarb flowers if you want to. To start with, you can use them as cut flowers and you can cook with them. Cool, eh?
As you can see, there are many advantages to letting your rhubarb flower and go to seed, not the least of which, in my case, is that it becomes an eye-catching, dramatic statement in the garden. So I don’t really hate rhubarb – the plant, that is!
If you do eat it though, there’s a solution: grow some rhubarb for your palate and grow some for your eyes. Definitely worth it, I would say!
Here’s the rhubarb as a structural element in my garden in early spring.
Copyright©2025 Elizabeth Spence
2 Responses
Elizabeth, I agree completely! I don’t like to eat rhubarb but have a plant that grows in terrible soil on my property. You’ve given me a new respect for it and the flowers it produces. Thank you.
Hooray – someone who agrees with me that eating rhubarb is nasty!!! Thanks Mary.