Rhubarb seems to be one of those plants that gardeners either love or hate. I fall in the former category. I could go on about how I appreciate the plant for its ornamental qualities, what with its big bold leaves and stunning red stems, but I’d be only half telling the truth. In reality, the reason I love rhubarb is simple – it’s the key ingredient, alongside apples, in one of my favourite desserts.
Rhubarb’s eating qualities were actually discovered quite recently. For a couple of thousand years, the plant was cultivated solely for its medicinal qualities. Chinese herbalists used the root of wild rhubarb as a purgative, and Marco Polo wrote about the plant in the accounts of his travels through China. Not until 1778 did people learn that they could cook, and eat, the plant’s stems.
The rhubarb that we grow in our gardens is commonly thought to be a hybrid, Rheum x hybridum, and a number of cultivars are commonly available at this time of the year. ‘Ever Red’ is one of the best for smallish gardens or pots. It forms a compact plant with deep burgundy stems that are produced over an extended harvest period. Another old favourite is ‘Glaskin’s Perpetual’, a more vigorous plant with red to green stems. Not all rhubarbs are red though, and ‘Victoria’ is an old green variety that tastes just as good. In my garden I grow a local strain called ‘Highfields Ever Red’
Because it hails from northwestern China, Mongolia, Siberia and Tibet, rhubarb needs a cold winter to break dormancy. Temperatures below about five degrees Celsius will get the plant growing strongly in spring, but there’s a catch – rhubarb also prefers coolish summers. Grown in full sun, dry soil, and a hot climate, rhubarb will wilt quicker than an iceblock in the Sahara. My plants are tucked in to a sheltered border of the vegetable patch where they receive morning sun, but benefit from a full afternoon of shade in summer. Still, I find that on warm days deep watering a few times per week might be needed to keep the moisture in those big parasol leaves.
While rhubarb loves a reliable supply of moisture, the crown will quickly rot if conditions become waterlogged. So in addition to a rich soil, a must for growing great rhubarb is drainage. Work in plenty of organic matter such as rotted manure or compost prior to planting, but if your soil is heavy black clay, try using raised beds. If you’re still having trouble, consider planting rhubarb in a decent sized container filled with top quality potting mix. A half wine barrel is perfect.
The most difficult aspect of growing rhubarb has nothing to do with the plant itself, but everything to do with patience. Don’t harvest any stalks for at least a full year from planting. For the less temperate amongst you, or those who, like me, have an addiction to stewed rhubarb and apple, this waiting game will be excruciatingly hard. But it’s worth it. Give the young plant time to develop a decent sized crown, and you’ll be amply rewarded.
When harvest time finally rolls around, always ensure you gently pull the stems from the crown, rather than cutting. Cut stems create an ideal entry point for fungal attack, and in wet summers, this can lead to crown rot. Also, it’s important to not harvest too many stalks in a single summer. Leave about half to grow to maturity and develop full sized leaves, as these will feed the roots that provide next summer’s crop.
Pests are rarely a problem. Slugs and snails can wreak a bit of havoc with the leaves, but this is mostly an issue of cosmetics. Flavour is unaffected. In my garden possums are the main threat to our enjoyment of rhubarb and apple for dessert. Believe it or not, they manage to eat the leaves without being poisoned, and in the space of a week, entire plants can be chomped almost to ground level.
One final word of warning: rhubarb leaves are high in oxalic acid. In other words they’re poisonous, and if you manage to chew through around five kilograms of the things, they’ll probably kill you. Seriously though, it’s best to leave them to the possums, and make full use of the stems. Rhubarb and apple – I can taste it now!
First published by The Chronicle 15th August 2009. Image by Emily Barney via flickr.
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Thanks for that Justin I thought as much and will get some more next winter.
I am currently growing rhubarb in a container of gravel which I am using to filter the water of a fish pond .Planted earlier this year how do I know when it is ready to pick and should I leave for another year.
I was born and grew up in Orange NSW. My Father always had rhubarb growing and we had it at least once a week. I have been buying it at the greengrocer now for 20 years and then made a big step of planting some. It has grown like mad, huge leaves and long green stalks, how long will it take to go red and be ready to pick and cook. At least a year from what I just read. Brand Renaissance. Has been in for about 9 months now.
Hi Kathy,
If your rhubarb is nine months old and the crown has bulked up nicely, you could start harvesting now. Depending on where you live, the plant may go dormant over winter and the leaves and stalks might get frosted back to the ground. Pick a few stalks and enjoy them, but don’t go overboard. The plant needs some leaves to collect sunlight and put energy back into its roots.
As for the green stems, some varieties will start to turn red as the weather cools, but odds are you’ve actually got a seed raised plant that might always be green. The safest way to get red stalks is to purchase a bare-rooted crown division of a properly named variety during winter. Green stalks are just as edible as the red, though in my opinion not as pretty on the plate and slightly less tangy on the palette.
Hope that helps,
Justin
Hi Justin
Thanks for championing rhubarb, a view I share. I recently harvested mine then transplanted it from an open bed to a large pot with added cow manure, in full sun (when we have it, I’m in Melbourne). It grew strongly almost before my eyes to leaves with a span of about 10 cms, then suddenly went all limp and sad. Do you have any advice?
Hi Pat,
If your rhubarb suddenly went limp, and died, the potting mix has either become too dry or too wet. My guess is that the latter problem occured. Rhubarb loves rich potting mix or soil and needs plenty of water, but it won’t tolerate soggy, swampy conditions. Pots sould have adequate drainage holes in the base. If only one hole is present when you purchase a pot, it’s often a good idea to make some extras with a masonry bit on your drill. Also, avoid sitting pots in saucers, as this practice also inhibits drainage.
Hope that helps,
Justin
I have two rhubarb plants that are 4 years old.
They arn’t turning red, how can I tell if it’s the type of rhubarb that doen’t turn red and just stay’s green
and if it stay’s green how to tell when to harvest it
If after 4 years your rhubarb hasn’t turned red, it’s almost certainly a green rhubarb, possibly grown from seed. The only reliable way to get a good quality red rhubarb is to obtain crown divisions from a properly named cultivar such as Ever Red.
As for harvesting, I generally suggest giving new plants about a year to develop before pulling any stalks. So a four year old rhubarb is well and truly ripe for the picking.
My rhubarb pumps! I live in south west WA. It has put out a large flower. Should I remove the flower or leave it there? (Does it affect flavour / productivity, etc??)
That’s entirely up to you Sherry. The flower will reduce the plant’s vigour a bit, but it doesn’t affect flavour. If you’re keen to grow some new plants, you can leave the flower head to do its thing, then collect the ripe seed for sowing in spring. You’ll get highly variable results from seed grown plants though, so if I were you, I’d be doing two things: cutting the flower stalk out, and digging up and dividing the plant. Rhubarb usually produces a flower stalk when the crown of the plant gets congested after about four to five years, so it’s a good idea to divide it up every few years to trick the plant into thinking that its young and vigorous. You’ll get quite a few divisions from a mature crown. Replant what you need, always making sure there’s a growing point (“eye”)or two above ground level, then give any spare divisions to friends or family.
Hi
I have a large robust plant that sits in its own large raised bed, surrounded by an old water tank.
It gets some sun, sometimes, depending on winter or summer,, this is its 3rd spot I have put it into,, now powering.
The stems only redden about a 3rd of the way up from the ground?
What is the best fertilizer to put on them?
I do use worm castings and juice, seaweed solution, thrive, dynamic lifter, chook poo and MPK blue, white and purple.?
I would like to get this thing onto our table but still not convinced the stems are ready,, it has quite a large crown,, as its been put, with a lot of stems.
Suggestions would be appreciated.
Cheers Jim Gray from Wandi WA
Hi can you tell me if rubarb is compatable with citrus,I would like to plant between a lime and an orange that are espaliered on the fence its about a metre from the truncks, facing east. Thankyou
Hi Chris,
I can’t see any reason why rhuabrb wouldn’t be compatible to plant near citrus trees. The plants enjoy similar conditions to citrus ie well drained soil high in organic matter, plenty of fertiliser and a regular supply of moisture. Some daqppled shade from the trees could be a bonus too. I’d give the combination a go. It could work well.
Cheers,
Justin
Justin,After a lifetime of “disliking rhubarb”but always cooking it for my husband – I found a recipe using red wine & sugar – voila I am now an avid convert. But, currently some of our crowns have huge big big leaves but short stalks. As I have been feeding my vegetables with a high nitrogen fertilzer, would this have caused the problem. Do you have a fetilizing regimne for rhubarb?
Many thanks Mazzab-Sunshine Coast
Hi Mazzab,
Rhubarb likes a rich soil and will grow in direct propertion to the amount of feeding it recieves i.e. lots of fertiliser will generally result in bigger plants. Are your plants grown from seed? If they are, it’s likely that some of the seedlings will never develop long stalks. To get top quality plants you need to grow rhubarb from quality, properly named crown divisions as these are genetically identical to the “mother” plant and will grow true to type. At the moment we are selling crowns of a good red variety called Silvan Giant. Please feel free to email me if you’re interested in purchasing a couple.
Cheers,
Justin
Dear Justin
Many years ago I seem to remember that my Dad grew massive rhubarb in a pile of almost pure fowl manure. Am I right?
Also, would rhubarb grow in used mushroom mulch?
How far apart should I plant and is Easterly aspect on the Mornington Peninsula victoria O.K?
Thank you so much for your most informative site.
Cheers
John F.H.
Hi John,
Rhubarb loves a rich, moist, but free draining soil and will grow in size almost in direct proportion to the amount of nutirents and water it recieves. The mound of pure fowl manure your Dad grew his rhubarb on proabably would have been aged – really fresh poultry manure can burn the plant’s fine root hairs. Don’t forget too that while massive rhubarb plants are certainly impressive, you’ll get more flavour from a plant grown just a bit leaner i.e. with adequate nutrients for heallthy growth, but not so much moisture and fertility that it becomes bloated and overfed.
Spent mushroom compost is ideal. It is generally slightly alkaline, which the rhubarb appreciates, and is beautifully decomposed. It retains moisture but facilitates drainage. However it is relatively low in nutrients, so you’ll do best by combining the compost with your existing site soil, along with lashings of blood and bone or a complete pelletised organic fertiliser.
Distance between crowns depends a bit on variety, but as a general rule, one metre spacings are plenty.
Happy growing!
Justin
Hi justin,
I live in Tamworth NSW and want to grow Rhubarb. Like you, I love it with apples for sweets. I haven’t been able to find the plant here to be able to grow it. Would you know where I can buy the starter (is is seeds? I keep reading ‘crown’…I don’t know what that is)? Thanks so much for your informative articles. Very useful for a novice like me.
Blessings, Fran
Hi Fran,
Botanically speaking, rhubarb is a herbaceous perennial, which means that it lives for more than a year (unlike an annual), and has non-woody stems like a shrub. The crown is simply the persistent, mostly underground base of the plant. Crown divisions are portions that are cut from the crown when a rhubarb plant is lifted from the ground in winter. You grow rhubarb from seed, but crowns are far more reliable.
If you’re after a couple, I’m selling a good quality red variety called Silvan Giant through my nursery. Prices are $10 per crown plus some postage. Let me know if you’re interested.
Cheers,
Justin
It is too late to divide my rhubarb patch (late August)
It has some new growth now
Hi Charlie,
It’s not too late to dig up and divide rhubarb. Pull off any stems and cook them up, as this will reduce moisture loss in the plant. Then dig the plant up and divide it into clumps using an old breadknife, ensuring there is at least one “eye” (new growth bud) per division. Then replant into soil enriched with compost and well rotted manure. Water in well and keep the ground moist unti the plant is growing strongly.
Best wishes,
Justin
Hi Justin, I live in Glen Innes (New Englanbd NSW) and am a keen gardiner. I grow Rhubarb in half a 1000 gal tank. It used to be my compost storage area. For two years the plant has grown very large leaves on the end of long pink stems. However all my crowns have seeded… Do I cut the seed stems and f;owers and start over? Or just let the plant survive on it’s own? Also some stems have a wooden apperance and do not cook up very well
Joe
Hi Joe,
Your rhubarb plant has bolted to seed, which often happens when the crown becomes congested over time, but in your case it may be due to some kind of external stress – perhaps the cold winter or drought. Rhubarb gets progressively more likely to bolt as it matures, so it’s important to rejuvenate the plant by digging up, and dividing the crown every few years. Becuase your plants aren’t yet that old, I’d be inclined to cut out all flower stalks as they appear, then water the plants well and give the soil a feed with pelletised chook manure in the hope that the crowns settle down again. If they keep trying to bolt, the plants will waste energy on flower development and the result will be poor quality stalks. If this happens you might be better to start again with new plants. You can grow rhubarb from seed, but be aware that the plants don’t come true to type – a batch of seedlings will be mixed, and it’s likely that most will be poor quality plants.
Hope that gives you a few ideas.
Cheers,
Justin
Hi Justin,
I’m writing from Ireland. I sowed store-bought T&M Glaskin Perpetual seed in July (our summer). I chose the 3 strongest plants and have been potting them on. They are in 2 litre pots of garden compost right now and look healthy. They are approximately 8 inches high with about 6 slim stalks each. We will be coming into our winter in just over a month so I’m not sure what the best thing to do next is. Should I continue to pot them up or will they survive if I plant them outside in the ground? We are expecting another bad winter of sub-zero temperatures and heavy snow again this year. My instincts tell me to pot them up and put them in the polytunnel until spring. But maybe that would hold them back, and I would like them established as soon as possible. I just don’t know how hardy these young plants would be if I planted them outside in the soil.
Thanks for any advice!
Graham
Do I have any hope of growing rhubarb on the Gold Coast – my mum the Gardner thinks it’s a hopeless dream but I love rhubarb and if we can grow fruit fly free tomatoes then why not rhubarb?
Hi Janenne,
Depeneding on where you are on the Gold Coast you might be able to get away with growing rhubarb. The plant is essentially a herbaceous perennial (not a fruit so no problem with fruit fly) that’s adapted to a temperate climate. It does much better in areas with a proper winter, but it wouldn’t hurt to try a plant out for a few seasons in your garden. Try and plant it in a cool spot with some afternoon shade.
Cheers,
Justin
Hi Graham – greetings from sunny Queensland!
In my climate (30-40 frosts per year, lowest temp -10C) the ideal time to plant rhubarb in the ground, whether the plant is a bare root crown or growing in a pot, is in late winter or early spring. I’m guessing that with your harsher winters and cooler summers, mid-late spring or even early summer may be better times to plant your rhubarb out. So yes, if a cold winter is predicted, I’d definitely be keeping the plants safe and sound in the polytunnel. The plants will go dormant and will probably die back to the crown, which is normal in cold winters. However dormant plants can rot if the potting mix gets too wet, so avoid overwatering. Keep the plants just moist. Once leaves appear and transpirations starts again, you can start watering more regularly.
Long term, the plants should be fine planted outside in the ground. You’ll need to ensure the soil drains freely, which generally means incorporating lots of decomposed organic matter prior to planting. During really cold winters, an insulating mulch of straw can be placed over the dormant crowns for protection, then removed in spring.
Hope that helps, and let me know how the plants go.
Cheers,
Justin
Hi Justin, I have two rhubarb beds about 2 metres apart (I’m in Melbourne) and one bed the leaves are developing brown spots with yellow edges around the spots and those particular leaves starting to wither. What could it be as the the soil and position in the two beds is the same? Appreciate you advice, cheers Lois
Hi Lois,
It sounds as though your rhubarb is infected with a leaf spot fungus. This is very common, and except in very bad outbreaks, the problem is more cosmetic than anything else. The stalks will still be edible. If you want to control the fungus, try harvesting the infected leaves, remove (and eat!) the stalks, then bin the rest. As a preventative, spray any new or unaffected foliage with a copper hydroxide fungicide such as Kocide or Yates Fungus Fighter.
Hope that helps,
Justin
hi,
We live in Geelong. Our rhubarb looks fat a healthy but is growing flat on the ground. Is the normal?
Thanks Anne
Hi Anne,
It’s normal for some of the leaves to lay quite flat but not all. Some should be growing strongly upright. I wonder whether you might have had a lot of wind or rain in your garden that’s caused the leaves to flop. A lack of moisture can also cause rhubarb leaves to lay flat, but I’m guessing that water stress isn’t a problem down your way this spring.
Another issue might be the variety you are growing. Seed grown plants sold in punnets tend to be highly variable and may grow in a less usual shape to most rhubarb plants. Properly named crown divisions produce the best quality plants.
Feel free to get back in touch if you need more advice.
Cheers,
Justin
Thanks Justin, answered all my query’s, I live in Tenterfield NSW.
why are my stems green not red & what can I feed them with to get
lovely red colour
Hi Marg,
You’ve got a green stemmed variety (possibly Victoria), so no amount of feeding will change the colour, unfortunately. A lot of rhubarb being sold these days is grown from seed, which means that the seedlings are highly variable – some are bright red, some are green some are half way between the two. For guaranteed red stems, you’ll need to purchase a bare root crown division of a properly named cultivar during winter. Ever Red is my favourite, but Wandin Red and Sylvan Giant aren’t bad.
Cheers,
Justin
Hi Justin have just been reading the letters and answers regarding Rhubarb growing and found them to be extremely helpful. I live in Victor Harbor South Australia and approx one month ago planted a crown given to me by a friend after first digging in some rotted Cow manure. It came through quite quickly with good size leaves but now seems to have come to a stop. It is in a shade area in the morning and gets the sun in the afternoon. Is this the best position. Kind regards Peter
Hi Peter,
The best position depends on your individual circumstances. Market gardeners in my area grow rhubarb out in full sun, but to do this successfully they’ll need loads of water. Those big leaves dry out very quickly, especially in free draining soil.
As a general rule, I recommend morning sun and afternoon shade for most home rhubarb growers. Your position is the opposite, but there’s no point in digging it up again now. See how it goes this summer, and perhaps consider moving the plant into a more favourable position while it’s dormant in winter. At this point in the year, crowns can be quite tricky to get established, so if yours has taken off and then stopped, try applying some seaweed extract to stimaulte root growth and get things moving. Be careful not to overwater, as this can rot the young crown – the soil should be evenly moist.
Hope the plant does well for you.
Cheers,
Justin
hi justin,
thank you for the comprehensive information! rhubarb is a favourite of mine also.
i’ve recently moved in to my new home and discovered i have rhubarb growing healthily beside a raspberry plant.
as i’m new to gardening, i was wondering what fertiliser is best for rhubarb? i understand it appreciates compost and rotted manure, but is there anything i should use to feed it? please bear in mind i’m a vegetarian, so i wouldn’t use blood and bone.
thank you kindly,
jessica (melbourne, vic)
Hi Jessica,
Both compost annd manure contain some nutrients. With the compost it depends what ingredients went into it in the first place, and with manure, it depends on the animal. Poultry manure is higher in nutrients than horse manure, for example. I always top dress my rhubarb in late winter with compost and a pelletised chook manure fertiliser (eg Organic Xtra, Dynamic Lifter), but you’d have to check the ingredients list of these products to make sure they don’t contain blood and bone or feather meal.
Beyond top dressing, you’ll get the most benefit from liquid fertilisers applied every month or so. If you eat fish, liquid fish emulsion such as Charlie Carp may be suitable. If not, I’d go for worm juice, or a liquid feed made by steeping chopped comfrey leaves and compost or manure in water for a couple of weeks. Make sure you dilute worm juice and home made liquid fertiliser to about the colour of weak tea before applying to your rhubarb. It’s a bit strong otherwise.
And keep an eye on that raspberry plant. It will sucker all over the place and happily swamp your rhubarb if you let it. Pull up any suckers that are growing where you don’t want them.
All the best,
Justin
Hi Justin
For many years now I have been growing rhubarb down the back of my garden in my vegie patch with great results. However last year I gradually lost most of my plants, seventeen out of about 20. These perfectly good healthy plants gradually wilted one day and within two days were completely dead. I had the soil tested with no major contaminents found. I left the ground fallow for a while then replanted new plants. These grew well until recently, when they started dying off again, not all together, but one here, one there. They are in good soil, get fertilized regularly and don’t seem to be waterlogged. They don’t seem to be suffering from any bug attack that I have noticed. Where am I going wrong, my rhubarb and apple dessert is suffering. Can you please help?
Regards Ian
Hi Justin,
My healthy rhubarb (2 years old) is being eaten by rats, or maybe possums. (I live next to a reserve.) Both leaves & stems have been attacked over the past three weeks.
I thought rhubarb leaves were poisonous? Is there anything I can do to protect the plants?
Hi Jill,
My guess is that the culprit is a possum. In past years they’ve eaten my rhubarb plants down to the ground. The leaves are mildly poisonous. A human being would need to consume more than 2kg to become very ill, so a possum, grazing every other night may be able to tolerate the toxins.
The only reliabel way to protect the plants is to put a cage or net over them. I’ve given up on products like D-Ter and Poss-Off, as they need to be continually reapplied after rain and the animals become habituated to them.
Hope that helps.
Justin
Hi Ian,
When apparently healthy plants start wilting and die within a few days that’s usually a sign of some kind of root rot disease. Wet soil is often the problem, but not always. Root rots can come in to the garden with nursery plants or other contaminated material, and over time they move through the soil profile to infest a large area.
If you have the space, I’d recommend digging up and transplanting the crowns into fresh ground or even some large pots filled with good quality potting mix. You could try doing this now (pick a cool day, trim off the leaves to reduce moisture loss and water in with seasol) or ideally in late autumn/winter.
I’d then get as much organic matter, especially home made compost, into the old rhubarb area as possible. The beneficial fungi in the compost should eventually outgun any pathogen fungi in the soil and create an area suitable for planting. Might take a couple of years to get it the soil back to health.
This is assuming that a root rot fungi is the problem. When you had the soil tested did the lab check for phytophthera?
Hi Justin
We live 0n the Sunshine Coast QLD , and I am wondering wether to remove the crown from the pot as our Summer is here and it has died back. Should I wrap it in straw as I am worried about crown rot.
Regards
Reg
Hello!
Just came across your blog!
Great read btw!
This post and subsequent comments about rhubarb caught my attention.
I love rhubarb, and have begun a website devoted only and entirely to rhubarb. Growing information, Nutritional information, and hundreds of online recipes.
Feel free to try some of the recipes!
Regards!
Lois
Dear friends
I have growing rhubarb which is looking healthy and my wife has just picked some stalks to stew for tea, i think it is too early as the stems are pink and not red as the plants have only been put in the ground early dec2011 i feel we may not get the benifit yet when we ahve it for desert tonight . Was it too early when it is pink to eat it?can someone answer this for me. First time growing rhubarb and other veges but it is fun just the same.
Hope to hear from someone who can help?
We live in port macquarie in n.s.w and the weather is hotting up so it is all going well so far even lady bugs have arrived and doing their thing.
Thanks guys
cheers James
Hi James,
The colour of the stems has nothing to do with the age of the plant. It can be influenced by the weather (some plants get redder stems in autumn/winter), but more than anything else, stem colour is determined by the variety that’s being grown. A good variety like Ever Red will have good red colour all year round, and all the way up the stem. Some varieties are pink, others are green. A punnet of seed grown plants will likely be a combination of colours. For guaranteed colour, it’s necessary to buy crown divisions, either sold as advanced plants in summer or bare rooted in winter.
It’s awlays a good idea to let rhubarb grow on for about a year or so before harvesting any stems. This gives the crown a chance to bulk up – every time a stem is pulled it weakens the plant a bit,so young plants can really be set back if harevsted too early. Give it time and the plant will reward your patience for years to come.
Happy growing!
Justin
If you make homebrew beer, feed your rhubarb with the dregs from your barrel after bottling the beer. I’ve done this for years and the rhubarb loves it.
Dave
Our rhubarb , single plant, grew very well, then suddenly changed from large single stems to many, many small plants that seem to grow too slowly, why have we lost our large stems? Do we dig up and break the masses down to a much lesser number ?
Hi Phil,
This often happens with older clumps of rhubarb and is easily rectified. In winter, dig up the clump, divide it into smaller pieces, then replant the divisions into soil that’s been improved with lashings of compost and well rotted manure. You should have fat, juicy stems growing again by late spring.
Cheers,
Justin
Hi Justin:- Have been reading your articles in the Chronicle for some time. They are great. We live at Gowrie Junction @ are growing rhubarb for first time. We were watering every day for half hour with sprays as I thought rhubarb needed a lot of water. We have stopped watering as one plant (WE have 3 varities) is starting to droop @ crown look like it is rotting. CI don’t know if it is crown rot or not? What can I do? Kind regards John Mortleman. 46307103
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