Jennifer Hoglin

Jun 9, 20208 min read

Rhubarb: The Pie Fruit

Updated: Jan 9, 2021

Funny thing about rhubarb. It's not actually a fruit, it's a vegetable. Its tart sweetness means it almost always gets relegated to the sweet side of the kitchen. It is usually used in pies, crisp and cakes. By definition, fruits have seeds in them. Vegetables, on the other hand, are the edible roots, stems and leaves of a plant. The part of rhubarb that we actually eat is the leaf stalk of the plant, just like celery. I know, weird, huh? Despite all this vegetable/fruit confusion, rhubarb is fantastically delicious and ridiculously easy to grow.

Rhubarb (Rheum rhaponticum or Rheum x hybridum) is a cool season perennial that is very winter hardy and also drought tolerant, making it perfect for the Calgary garden. Plants are quite long lived, easily lasting for 20+ years with little to no care. So if you have a spare 4 square feet of room anywhere in your yard, you can't go wrong with rhubarb.

Still very early spring. This guy will get twice as big by the end of the summer.

Origins

The rhubarb we grow today originated in the cold regions of northern Asia (Siberia and Tibet) and was brought by Marco Polo to Europe from China. No wonder it is so hardy! The Chinese used the roots of rhubarb in traditional medicines for thousands of years, and still do today. (Do not use rhubarb root yourself without the guidance of an herbal medicine professional as it can be toxic if used incorrectly.)

Growing Rhubarb

Where to grow

Honestly, rhubarb will grow pretty much anywhere. It prefers full sun to partial shade, but I have seen it do fine in quite shady spots too. It also prefers average to moist soil (even some standing water) but will handle drought as well. It is not particular in terms of soil type or pH, and is highly tolerant of urban pollution. Are you getting how easy to grow rhubarb is? Rhubarb is technically a zone 3 plant, but it can take a tonne of abuse before quitting on you.

True story: I once dug up my rhubarb, with the intention of replanting it elsewhere in the yard. I set it in the back alley on top of the gravel road, where it sat, forgotten. No one watered it, or cared for it in any way. In fact, my husband actually ran over it with the truck a few times, not knowing that I was going to replant it. When I finally remembered my poor rhubarb plant more than 2 weeks later, I quickly dug a hole in my garden and got it in the ground, apologizing to the plant the whole time. And guess what? It grew! With absolutely no animosity towards me at all. That's how tough rhubarb is.

As indestructible as it is, rhubarb does need a fair amount of room, as each plant gets approximately 4 feet high by 4 feet wide. No matter how tiny it looks when you first get it, make sure it has room to spread out.

Planting

The easiest way to get rhubarb in your own garden is to make friends with someone who already has it growing in theirs. Then, when your friend goes to divide theirs (see below), snag a chunk of it for yourself. If you don't know anyone with rhubarb in their garden, you can always purchase crowns from a garden center. They are widely available. Look for plants with lots of new growth from the crown and at least 2 or 3 buds growing from it. Plant when the weather is on the cooler side, spring or fall is best. Adding lots of organic material to the soil around your plants will help tremendously with growth. Compost is a fantastic source of organic material as well as minerals, nutrients and beneficial organisms.

Rhubarb crown with lots of buds (photo by Pixabay)

You can also grow rhubarb from seed, but it will take a number of years before it will get to a harvestable size. It is much easier to start from a division, unless you are keen to grow one of the more rare varieties.

Varieties

The most common and most widely available variety of rhubarb is Canada Red. It is also the one that has been around the longest, so if you stumble across a rhubarb plant on an old homestead, that is most likely what it is. Other red varieties include Valentine, Macdonald, German Wine (which is more pink) or Victoria (which is red with a green top half). There are also varieties that don't turn red at all, just stay green. Riverside Giant and Turkish are two such varieties. These are less popular, as the rosy red colour is one of the best parts of rhubarb. Many of these varieties will be available only from seed.

You should also be aware that there are a few varieties of ornamental rhubarb available in garden centers. These are not so good to eat, although they do look fabulous in the garden.

Care and maintenance

Rhubarb requires very little in the way of care. Many people remove the large flower stalks once they see them forming. It is thought that allowing the plant to flower will reduce the amount of new stems that form. This use to be a common practice, but many people are arguing that there is no proof this is true. It is your preference. Personally, I like to cut them and bring them inside to put in a vase. They are huge and very original looking flowers.

If your rhubarb plant is starting to put out many shoots and looking especially crowded, it may be time to divide it. It is not a mandatory job, but should probably done at least every 20 years. Dividing is best done in the spring when the plant is first starting to bud as the plant is far easier to handle when small. It is done by digging up the entire plant with all of its roots, and prying it into multiple chunks. Make sure each chunk has 2 or 3 buds (also called eyes) on it. The root ball can be really tough so don't be afraid to use whatever method necessary to get it apart. A hand saw may be required. Discard any dead sections of the root ball. Plant as you would any transplant, with the crown at the same soil level as it was before you dug it up. Dividing is a great way to get additional plants and a great way to make garden friends. As I have said before, gardeners are great sharers.

Rhubarb is rarely bothered by pests. You may occasionally have a bit of damage to the leaves from flea beetles, slugs or aphids. But don't let that worry you as we aren't going to eat the leaves anyway! Please do not use insecticides just to prevent a minimal amount of cosmetic damage. All that is required to keep it healthy is a yearly top up of compost and maybe some mulch to help keep the soil moist.

Harvesting

This will be hard, but you really shouldn't harvest any stalks from your rhubarb plant the first year you plant it. And you really shouldn't harvest more than just a few stalks the second year you have it either. If you want to give your plant its best chance at healthy growth and the time it needs to get its roots well established, you really should wait until your rhubarb's third year after transplant before you take a significant harvest from it. This also includes waiting three years after dividing and replanting. It sucks I know. But your plant will thank you with abundant harvests for the next 20 years.

A one year old transplant from a division.

Rhubarb is ready to pick when it is about 7-15 inches long. Colour is not a reliable indicator of ripeness, as colour is determined more by variety type and plant maturity. Only take up to 1/3 of the stalks at any one time. You want to be sure that the plant has enough leaves left to photosynthesize and store energy for survival through the winter. This is particularly true when harvesting in fall. Speaking of which, it is best to harvest in spring or fall, as that is rhubarb's peak growing times. Remember, it is a cool season lover. Growth is considerably slower in the hot months of summer.

The best way to harvest rhubarb stalks is to grasp the bottom of the stalk, twist slightly and pull (see photos below). Pulling encourages the plant to produce more stalks, while cutting them does not. Harvest the larger outside stems first and work your way towards the center.

The leaves of rhubarb are not for eating. They contain oxalates and anthraquinone glycosides which are toxic. Make sure you completely remove them when harvesting. They do however make fantastic additions to your compost bin or chopped and dropped on your garden beds to decompose naturally. They are a good source of organic material and nutrients for your soil. See the article Intro to Food Forests for more information on nutrient accumulators and mulch plants in food forest guilds. Many people also use the leaves to make a natural insecticidal spray, especially good for aphids. I haven't tried this out myself, so if you try it, let me know how it works!

Rhubarb in the Kitchen

Rhubarb has been in prairie gardens for generations and there are many family recipes around for baking with it as a result. It has always been a reliable and early season fruit from the garden. It is also one of the most versatile fruits/vegetables in the baking world. Not only is it used in pies (it is called pie fruit after all), but it is a standard in cakes (especially coffee cake), muffins, bread puddings and any type of baked good with fruit on the bottom and pastry on the top. My family has always been partial to crisps, but there are also cobblers, crumbles, buckles and Brown Betties. Rhubarb is traditionally paired with strawberries, as they add sweetness to rhubarb's tartness and are usually ripe around the same time. It also pairs well with ginger, vanilla, and pretty much any other berry.

If you have a bumper crop of rhubarb, it is convenient to chop it up and freeze in Ziploc bags until you are ready to use it. Freezing in the exact portion you need for your favourite recipe will make it even faster to whip up. If you don't want a big clump of frozen rhubarb, let air dry first and spread out on a baking sheet to freeze. Once completely frozen, portion into air tight containers. You can then take as much as you need, whenever you need. Making as many pies as possible and freezing them for a later date will ensure you always have homemade deliciousness ready for guests. It's not wrong to bribe family into behaving at gatherings with rhubarb pie.

One last quick tip: rhubarb juice can be used just like lemon juice to prevent discoloration in apples, pears and bananas. Just smash chunks of rhubarb in a garlic press to extract the juice into your soaking water.

The First Fruit of the Year

I cannot imagine a year without rhubarb fresh from the garden. One of my earliest memories is sitting with my little sister, with a shared bowl of plain white sugar. We would each dunk our own rosy stalk of rhubarb into the sugar and then viciously rip off a chunk with our teeth. It was tart and sweet and juicy and sticky all at once. To me, that will always be spring in the garden.

And yes, I let my own boys have a bowl full of super unhealthy white sugar to dunk their rhubarb in. It is the only proper way to celebrate spring.

Yummy gardening everyone!

Recipes

Gingered Citrus Rhubarb Jam - by Bernardin. This is one of the standards I make every single year.
Rhubarb Cake - a family recipe that everyone loves.
Rhubarb Custard Pie - a tart sour cream filling with a crisp, sweet brown sugar crumble
Earl Grey and Vanilla Rhubarb Jam - original recipe from Food In Jars, but I like the variation here by One Hundred Dollars A Month. This is my absolute favourite jam ever!
Rhubarb Compote (recipe coming soon)
Sunshine Rhubarb Juice Concentrate - from Canning Homemade! is a great for making healthy juice or a pop substitute (if you use soda water) for the kids. Or make grown-up drinks by adding vodka. Great for camping season!
Rhubarb Butter (recipe coming soon)

Can you tell I always have lots of rhubarb? I told you it is reliable!