The ultimate rhubarb guide to growing, harvesting, preserving and cooking with rhubarb. Get lots of tips for growing this easy perennial food plant plus delicious recipe ideas for both sweet and savory dishes.
This rhubarb guide is a part of a continuing series of produce Ultimate Guides where you can find all kinds of growing information and tips as well as delicious recipes, both fresh and preserved, for a specific fruit or vegetable. See more fruit and vegetable guides here.
Rhubarb is one of those edible plants that's considered a vegetable, but used like a fruit - in fact a US court decided in the 1940s that it was a fruit for import regulations because that's how it's often used (source).
It's probably considered a bit unusual or old-fashioned, but it has some great qualities and lends itself to some fantastic recipes, so I really recommend growing it.
One reason is that rhubarb is a perennial plant and once established in a place that it likes it's pretty carefree, coming back every year with minimal care.
So you need a permanent place - a rhubarb patch - where it can happily live and provide you with some of the first fruits of the gardening season year after year.
Another reason is that rhubarb is such a versatile plant to cook with and preserve - it can become a chutney for savory foods, ice cream sauce, pie and cake filling, jam, cookie bars, drinks and more.
Even so, it is still a mystery to some because it's not a normal thing we find regularly in our supermarkets.
I often get questions asking what to make with rhubarb or how to grow it, so I'm putting all the rhubarb growing information and recipes that I've collected into one ultimate rhubarb guide so you'll have one place to come for rhubarb answers.
What is rhubarb?
Did you know that rhubarb is a member of the buckwheat family? So weird, right? It also has good amounts of vitamins C, K, and the mineral magnesium as well as some fiber and protein.
We eat the stalks of a rhubarb plant and they are known to be quite tart, which is why many recipes call for quite a bit of sugar. I've found I can easily use less to get a nice sweet-tart flavor, so my recipes use less sweetener and many use a natural sweetener, too.
The large leaves of the plant are poisonous (I always feel sorry for the people who discovered stuff like this, don't you?), so they should be composted after harvesting the stalks.
Additional information on the toxicity of the leaves:
Rhubarb leaves contain oxalic acid - in addition to other compounds that may be bad for humans (see this article for more on this). Other vegetables have oxalic acid, too, like spinach, chard, broccoli, cauliflower and brussels sprouts - only in smaller amounts which you can lower even further by blanching and draining the water.
However, you would need to eat a large amount of rhubarb leaves to be considered to be toxic, though small amounts may cause digestive distress.
According to the article linked above, in WWI Britain encouraged eating rhubarb leaves to help with food shortages and there were numerous illnesses and one death, which has not been reported with eating spinach and chard.
Based on this and other sources like this I will continue to advocate growing this lovely edible plant for it's stems only and composting the leaves.
Red or Green Stalks?
I didn't know until we moved into a new house with an established rhubarb patch that not all rhubarb varieties have red stalks. Some produce mostly green stalks with barely a hint of red.
The green stalked rhubarb is closer to the wild rhubarb, with newer varieties having been bred to be redder, like 'crimson red' and 'valentine.'
I've cooked with both types and while there is no flavor difference, the food all looks better using red stalks. They make the jam pretty (it's a dull brown color with green stalks) and produce wonderful red pockets in muffins and breads.
Green stalk rhubarb also tends to produce more flower stalks (some of the red varieties will not produce flowers at all), and when the flowers form, the stalks can be a bit dry and stringy.
However, the green stalk variety is hardier and easier to grow than the more popular red colored plants, so if you're having problems getting rhubarb established, switching your variety may be an option for you.
Ultimate Rhubarb Guide - How to Grow Rhubarb
Rhubarb is most typically planted as one-year-old crowns, either bare root in very early spring or from potted plants in later spring.
Plant in the spring as early as you can in full sun and amend the soil a bit with compost before planting rhubarb crowns about an inch below the surface.
TIP: in warmer climates, rhubarb may do better in partial shade, though the stems will not grow as thick.
If planting more than one plant, set them at least 3 feet apart - a well established plant can grow huge!
Do not harvest the stalks at all the first year after planting to allow the plant time to grow with its full energy (although if it looks really healthy, it probably wouldn't hurt to harvest 2 or 3 stalks to make some muffins with!).
Water well and consistently throughout the growing season, especially in the plant's first two years.
After that, I've found them to be fairly drought resistant - they will die back if not watered, but will produce again the next spring. Of course that's not the way to get the best, biggest stalks, but if you can't provide water throughout the entire season once it's established, it should be okay.
The only fertilizer it needs is a yearly topping of compost. Keeping the ground mulched with a layer of the compost, grass clippings or straw is a way to keep the ground moist as well. Just keep any mulch away from the crown of the plant, which can encourage rot.
To prepare your plant for winter, after the first hard frost, cut back any remaining stalks and dress with a light 2 inch layer of compost, leaves, or hay to protect the roots through the winter.
The only other thing to remember is to remove any flowering stalks that may appear (as mentioned, some varieties form more of these than others), as they take away the plant's energy as well as cause the stalks to degrade in quality.
Established clumps can be divided every 4 to 5 years - when the stalks get small and spindly or when the crown is visibly crowded. This will help the plant keep growing nice thick stems.
You can dig around the edges and trim the crown down to 4 or 5 buds or you can dig most of the plant up and gift somebody with a rhubarb plant.
Growing in Shade or Heat
Above is another rhubarb plant I planted in dappled shade. It illustrates what was mentioned above - rhubarb grown in more shady conditions will have thinner stalks and the plant and leaves won't be as large.
If at all possible, move to a sunnier spot unless the shade is allowing your plant to grow in warmer climates.
Although rhubarb isn't known for growing well in the hotter southern United States, providing shade and water (and choosing the greener variety) may allow you to grow it successfully in areas with warmer summers.
The top growth will probably die back at temperatures consistently above 90 degrees, causing the plant to appear dormant, but as temperatures lower in later summer the leaves should start to grow again then or the next spring.
If all you can grow is rhubarb with thinner stalks, I'd vote for growing them!
If you live in an area where rhubarb isn't sold that you know of, the easiest way to make sure you can have some each season is to find a way to grow it.
How to Harvest Rhubarb
To harvest individual stalks:
The easiest way to gather the stalks is to pull up from the base of the plant, twisting slightly as you pull.
Most will come out pretty quickly this way, but if some don't, you can use a knife to cut a stalk off at the base, you just have to be careful not to cut anything you don't plan on harvesting - which is why I prefer the pull-and-twist method.
Cut off the leaves and compost them.
When and how much to harvest:
I've read various, sometimes conflicting, methods for when and how much to harvest your rhubarb - from only picking 1/3 of the plant during a season to cutting all the stems at once for a one-time harvest, or only spring harvesting to an all-season harvest.
I aim for the middle, harvesting only the fattest stalks for about a two-month period, or until most of the new stalks are really looking thin. Every once in awhile, some stalks will look good again in the fall and I'll harvest a few, but my main harvest is in the spring.
Ultimate Rhubarb Guide - Recipes
Honey Rhubarb-Ginger Jam (Small Batch)
Ten Ways to Use & Preserve Spring Rhubarb @ Food In Jars
Rhubarb freezes wonderfully! Trim, slice or dice, and pack raw into freezer bags, removing as much air as possible (I use the straw trick).
Alternately, you can flash freeze the cut rhubarb on a baking sheet before adding to freezer containers.
Either way, label and freeze for up to a year.
TIP: Cut and freeze in measurements of your favorite recipe and to use it easily from frozen.
Cooking & Baking Recipes
Old Fashioned Fresh Rhubarb Cake @ On Sutton Place
Pink Rhubarb Gin @ Lovely Greens
Rhubarb Sorbet @ Garden Therapy
Rhubarb Coffee Cake @ Attainable Sustainable
Pasta with Basil & Rhubarb Sauce @ Recipes From A Pantry
Homemade Rhubarb Bread @ Creek Line House
Rhubarb Frequently Asked Questions
If harvesting from a garden patch, cut off the poisonous leaves before bringing inside. Cut off the bottom root end and use a vegetable brush to gently clean each stalk under running water. Then chop into the slices or dices needed for your recipe.
You do not need to peel spring rhubarb, since the stalks are tender enough to be used without peeling. If you are using later season rhubarb the strings of the stalks may be tougher and you may want to peel first.
You shouldn't eat rhubarb from the garden once temperatures fall to the lower to mid 20s, as oxalic acid in the leaves will move to the rhubarb stalks which can crystallize in the kidneys. (source)
It will keep in stalks 3-4 weeks in the fridge, a little less if cut. You can store wrapped in a damp cloth inside a produce bag or alone in the produce bag if using sooner.
This guide has been updated - it was originally published in 2014.