How to Grow Rhubarb

If there’s an argument about the chicken and the egg and which of them came first, there’s a similar argument when it comes to rhubarbs.

Is the rhubarb a fruit or a vegetable?

But before we answer that question, we need to first learn more about this plant.

The History of the Rhubarb Plant

rhubarbs on a wooden background

If you love pastries or desserts, chances are you’ve had a taste of rhubarbs. You might have either eaten one unknowingly or already know that they are perfect for pies, especially when combined with strawberries and other fruits.

Rhubarbs add richness to the taste of food it is combined with, but did you know that it also has a rich history?

Growing them was common in Northern Asia, especially all over the Silk Road, for centuries due to its perceived medicinal properties. But in the United States, people only started cultivating them sometime before the 1800s, allegedly after a gardener in Maine planted a rhubarb seed that came from Europe.

Later on, rhubarb cuttings had to be smuggled by women who wanted to use them for food because it was valued to be near-worthless at that time. Laws back then prohibited people from transporting items that were worth not more than a dollar for every pound.

People soon discovered that rhubarbs actually tasted good when used for jams, sauces, and even pies. This led to them using this “worthless” plant as a main ingredient in various dishes that they eventually sold for huge profits. It was commonly used in pies back then, even until now, and that’s why it’s also known as the “pie plant.”

rhubarb jam

What is a Rhubarb Plant?

To answer the earlier question, the rhubarb is really a vegetable but is also eaten like a fruit. This is why so many people get confused with this plant. Eventually, the plant was legally classified as a fruit in the US after a court decision in New York. Yes, this confusion even reached the courts! Although this declaration has more to do with the imposition of tariffs on imported vegetables, rather than what it really is.

As a vegetable, it is part of the polygonaceae family, better known as the buckwheat family. This plant is also an angiosperm and this means the rhubarb is also a flowering plant.

Despite the confusion about what it really is, it’s easy to distinguish a rhubarb plant. It looks like a red version of a celery, due to its stalks having their signature reddish color, with the intensity of its color depending on its variety. Field-grown rhubarbs have redder stalks and hot house-grown rhubarbs have pinkish stalks.

The rhubarb is a perennial plant, which means that it lasts for a minimum of two years, usually more. Although this plant has a long lifespan, its harvesting season is actually quite short.

The Delicious and Toxic Rhubarb Plant

Now that you have a basic idea of the rhubarb plant, you would probably think that all of its parts are edible. After all, you can generally eat the stalk, leaves, and even the flowers of vegetables.

The rhubarb, however, is another story. Only its stalk is fit for human consumption. You can eat the stalks raw, which has a very tart taste and you deserve a pat on the back if you can withstand this tartness. However, they are best used as ingredients for various pies and sauces, especially when combined with sugar.

The leaves, on the other hand, should never be eaten. These leaves, not the stalk, are the ones that should be thrown away due to its toxic nature. This is because they contain toxins that are dangerous to humans, oxalic acid in particular. These leaves are also said to contain anthraquinone glycosides, which is another toxic substance.

If you accidentally eat the leaves, you will experience various symptoms of food poisoning, such as nausea, diarrhea, difficulty in breathing, a burning sensation on the inside of your mouth and even your throat, stomach pain, and many others. It only becomes fatal when you eat too much. Best to err on the side of caution and don’t eat the leaves at all.

Its flowers can also be eaten but make sure to remove the flower stem, which also contains oxalic acid. It also tastes quite sour and most people don’t really use the flowers in the kitchen; they’d rather use it for ornamental purposes.

The Health Perks of Having Rhubarb Plants at Home

Growing rhubarb plants in your own backyard is highly recommended, even if you are not a fan of pastries. Although they are better known as a main ingredient for various dishes, you can actually get so many health benefits from consuming rhubarbs. Some of these include:

  • Providing various vitamins and minerals – it’s a vegetable, so it’s definitely expected. But did you know that even just a single serving of rhubarb can provide you as much as 45% of your daily required amount of Vitamin K, which is necessary for you to have healthy bones? Not to mention that it also has Vitamins A, B-complex, and C, lutein, manganese, iron, and so many others.
  • Aids in digestion and relieves stomach issues – the rhubarb contains a high amount of fiber and it is a fact that fiber is very helpful for your digestive system, especially when it comes to your bowel movement. It can alleviate constipation, stomach bloating, and other related pains. Some studies also show that rhubarb, when taken in powder form, can help cure stomach bleeding.
  • Can be used as a natural laxative – you already know that the rhubarb is rich in fiber and helps remedy issues concerning your digestive system. It’s no wonder why it is widely used as a purgative for centuries and all over the world, especially in Asia where many people still prefer traditional and natural medicines.
  • Used to treat cold sores – you can actually use them to treat your cold sores by directly applying it to the affected area. This is especially effective when combined with sage.
  • May help prevent cancer – they contain various antioxidants, particularly polyphenol, and studies have shown that these can possibly prevent cancer. More studies, however, are still needed to confirm its effectivity in cancer prevention.
  • Helps lower cholesterol levels – this is because the rhubarb has a low sodium content, which directly affects your cholesterol levels. In turn, it will help protect you from acquiring various cardiovascular diseases.
  • Good for your brain – it was already mentioned that the rhubarb is rich in Vitamin K. Not a lot of people know that this vitamin is actually beneficial for your neurological health as well, involving your brain in particular. Consuming rhubarbs can even help prevent you from having Alzheimer’s disease.

Would you believe that the list above is just a fraction of the many benefits of having rhubarbs growing in your garden and eating them? No wonder people are calling the rhubarb a “superfood” nowadays.

Growing Rhubarbs 101

Are you now interested in planting and growing rhubarbs? Then you need to sit up and focus as we teach you how to make them thrive in your garden.

In the US, rhubarbs are grown throughout the country because they also thrive well in hot houses aside from gardens and large plots of land, although many of those who plant them commercially are found in the Pacific Northwest Region, especially in Pierce County in Washington, and Michigan. It is a fairly easy plant to grow no matter where you are.

Like other similar plants, you can grow them from seeds or using some of the older plant’s parts, specifically its crowns or budded pieces. But if you are a beginner, it is recommended that you grow them using the crowns from those at least a year old or budded pieces of rhubarb plants that are at least two years old.

Since rhubarbs have plenty of varieties, you need to choose which one to plant. Popular varieties that you can grow at home include ‘Victoria,’ ‘Champagne,’ ‘Raspberry Red,’ ‘Delight,’ and ‘Glaskin’s Perpetual.’ Among these, the ‘Champagne’ variety is most suitable for beginners.

Where to Plant Them?

As soon as you decide which variety to plant and have gathered all your necessary gardening equipment, you need to choose where to plant your rhubarbs.

First, make sure that you have space for them to grow. Your rhubarbs should have some ample space in between, ideally 1 to 2 feet, for them to spread out as they grow because their roots will take up a lot of room.

They also don’t do well in hot locations, so they should be placed somewhere warm or cool. This area preferably must have average temperatures of less than 75˚F during the summer season and not more than 40˚F at wintertime.

It is important that where you plant them will be their permanent location. Rhubarbs hardly survive being transported, so it’s not advisable for you to plant them in small pots first then transfer them later when they grow.

When you decide on the location, it is vital that you first get rid of weeds in the area where you are going to plant the rhubarbs. If not, those weeds will soak up all the nutrients and eventually kill your plants.

Ideally, they should be found at the edge of your garden so that they won’t disturb your other plants when they grow back after hibernation.

The location should also depend on the kind of soil you will use. It is advisable for you to use soil that drains well but if your entire garden is on the damp side, you need to elevate your rhubarbs and use raised beds for ample drainage. Good drainage is also important for your house to avoid damage to the foundation. Since loam soil contains those properties, you should read our article about the topic.

When planting, make sure that the holes where you will place your crowns are not that deep. 1 and a half inch deep holes are just enough, but ensure that the soil around the hole is firm, not loose and crumbly.

Full Sunlight or In the Shade?

The answer is: both.

However, rhubarbs thrive best when they get full sunlight. They should be placed in a location where they can get exposed to sunlight for 6 hours or more in a day.

But if this is not possible, don’t fret. They can also grow when they are placed in semi-shade.

Some even force their rhubarbs to grow by covering them with terracotta or clay pots or bins. Don’t expect them to last long though if you keep forcing them because depriving them of sunlight will weaken them, especially when you do it every year.

When Should You Plant Rhubarbs?

Most plants have ideal seasons when you can plant them. For rhubarbs, it is only during early spring for seeds and autumn for crowns.

If you plant rhubarb seeds during springtime, make sure that you do it when the ground has already thawed from winter and the roots of other plants are still dormant or when your other plants start to show signs of growing out their leaves after being dead all winter. Knowing about the last frost date is imperative in the growing of this plant.

When planting rhubarb crowns during autumn, do it later in the season or just when winter is about to start. The perfect time is when your other plants have begun to hibernate but the ground is not yet frozen solid.

Should You Use Fertilizers?

Like other plants, rhubarbs need nutrients to grow. This is where fertilizers come in.

Before you plant them, you can mix in well-rotted manure and compost to the soil where you will plant them. These plants are considered as “heavy feeders” and need all the nutrients they can get from fertilizers. You can’t really just rely on plain soil.

It is important that you avoid using chemical-based fertilizers anytime within its first year, because the nitrates in those fertilizers are harmful to young rhubarbs and can prevent them from growing and can even kill them. Consider tilling the soil in preparation for the planting also.

As soon as the spring frost is over, you can add a little fertilizer with a high nitrogen content (either 10-6-4 or 25-3-3) by sprinkling them over the soil, but make sure that it is just enough to penetrate the soil but not the actual root systems themselves.

As your rhubarbs grow, you should add mulch that consists of cow manure and straw to prevent weeds from growing and your soil from drying out, aside from giving your rhubarbs its much-needed nutrients. You should do this every after growing season, usually in the middle of summer and also sometime in autumn.

How Do You Care for Rhubarbs?

While rhubarbs are low maintenance and are easy to grow even for beginners, it still helps if you give them some good old TLC.

The most important thing to remember is to never let them dry out. These plants hate experiencing drought, especially during the summer. Keep its soil moist but make sure not to overwater them as well. Balance is key.

Overwatering, as well as having poor soil quality, contributes a lot to crown rot. This is the most common reason why they die and it often happens to young rhubarbs. Crown rot also happens when the growing tips of the plant cannot surface from the ground because they are buried under your compost or are too deep in the ground.

Rhubarbs are flowering plants and it is advisable that you remove those flowers or seed stalks as soon as they sprout. It usually starts when the plant is around two to three years old. These seed stalks and flowers, when left to grow, will soak up all the nutrients needed by the plant and this will give you poor quality yields, not to mention it can later kill the entire plant.

Something you should also watch out for is when it shows signs of having a disease. Rhubarbs can get the Verticillium wilt, which is characterized by the early yellowing of its leaves. When this happens, you need to cut and throw away all those parts that show disease, even if their stalks seem healthy.

While they generally don’t attract garden pests, they can still fall victim to cabbage worms and European corn borers. But the most common pest that affects these plants is the rhubarb curculio. This beetle is identified by its rust color and a total length of ¾ inches. You can simply pluck them away from your plants to get rid of them. Do make sure to remove their eggs as well.

If you’ve been gardening for some time, chances are you’ve encountered slugs and snails feasting away on your plants. Unfortunately, this also happens to rhubarbs so make sure to check for signs of their infestation and remove them as soon as you see them.

When Can You Harvest Your Rhubarbs?

You might get excited to see your young rhubarbs already looking ripe for harvest during its first year. However, what you should know is the golden rule when it comes to these plants.

Never harvest rhubarbs during its first year of growth, no matter how much these rhubarbs look juicy and perfect for baking pies and making jams.

Patience is important when it comes to harvesting because during its second year, when they are finally ready to be harvested, you can expect your rhubarbs to be as long as 18 inches and the succeeding harvests on the next years will be just as good, if not better. The entire first year you left it unharvested allows your rhubarbs to establish itself, resulting in great harvests for years to come. Of course, this will only happen when combined with proper care.

Harvesting is quite easy, since you just need to pull the base of the stalk away from the crown of the plant. If you cannot do it by hand, you can also cut away the stalks using your gardening tools, such as a knife or pruning shears.

Make sure that the stalks you want to harvest are not thin because thin stalks mean your plant’s food reserves are quite low and they should be left alone. The leaves are also a good indicator; choose stalks whose leaves are already fully developed.

When you harvest, do not remove all the stalks available. Just get around half of it at most to allow your rhubarbs to produce again for the next year. You can start by harvesting a few for the first time (again, only during its second year) and increasing your harvest over the years.

You should immediately remove the leaves and add them to your compost pit as you harvest.

Do remember to finish harvesting before August comes to allow your plants to rest up for the next growing season.

Don’t worry about having too much rhubarb stalks harvested; they won’t really be wasted. Aside from doing a good deed and sharing them to other people, you can also freeze them to be used throughout the year until your next harvest. They also do well when they are preserved or pickled.

When Can You Cut Rhubarb Plants?

By following this guide, you should already know by now how you can grow and harvest rhubarb plants. The last thing to talk about is how to cut them.

Cutting does not mean shaping your plants, though. You can’t really do that with rhubarbs. When it comes to these plants, cutting is more for maintenance purposes and to promote healthy growth.

Remember to immediately remove the leaves every time you cut your rhubarbs and dispose them afterwards or add them to your compost.

If you paid close attention throughout the article, some of the times when you should cut your rhubarbs were already mentioned.

The first is when seed stalks and flowers begin appearing on your rhubarbs. Make sure to keep an eye on them because these can sprout as often as every 2 or 3 days. Regular cutting of flowers and seed stalks will eventually stop them from appearing.

The second is during harvest time, again only starting from the second year. Keep in mind the proper ways to cut away the stalks to allow your rhubarbs to continue propagating over the next years.

Another is when frost occurs, usually during the onset of winter or as early as towards the end of autumn. During this time, your plant may hibernate so you need to cut off all of its dead stalks only. But if some of these stalks are not dead, especially when your place is only experiencing mild winters, leave them alone.

When your rhubarbs are mature, usually after 3 or 4 years, you can already divide them and plant in another location for propagation. The perfect time is when your rhubarbs are already crowded and you’ve noticed that the stalks are getting thin. You can dig them up and split up the roots, with each of their crowns having at least one bud available. You can only do this during early spring when the plants are still dormant.


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