Rhubarb is a very easy vegetable to grow (yes vegetable). As long as you plant it in a spot with the right conditions and follow a few care guidelines it will thrive. In fact, in my experience, once it’s established it’s hard to kill. It can take years of neglect before it dies off. It’s not a fussy plant but for the best results, you do need to follow a few rules which I will detail further on.
What Is Rhubarb?
First off, rhubarb is a herbaceous vegetable, not a fruit as many assume. And that’s because while it’s a vegetable it’s often used for culinary purposes in the same way as fruit. Raw, the stalks are crisp and tart so it’s often served stewed with sugar (and often strawberries) to soften its texture and sourness.
There are many different varieties of rhubarb and the color of the stalks can vary from crimson red through speckled light pink, to simply light green.
How To Plant;
Rhubarb grows best in zones 3 – 8 where the necessary winter cold periods allow the plant to break dormancy and grow. As rhubarb is a perennial that will live for anywhere from 10-20 years, make sure to choose a planting location where it will be happy to stay for years. Rhubarb does not need to be rotated. It will do best in a location with full sun or light shade. It doesn’t like extremely hot weather so will produce best in cooler conditions. However, it will tolerate some heat as long as it gets enough water. Rhubarb can be grown from seed, divisions, or crowns but you will be able to harvest sooner if you plant crowns.
Planting Crowns (or Rhizomes);
Rhubarb crowns are established plants that are at least 1 year old. Plant crowns in early spring in rich, well-drained soil that is slightly acidic, ideally with lots of manure. Crowns can also be planted in the fall as soon as dormancy has set in.
Spacing each crown about 4 feet apart, dig large holes about the size of a basketball. Mix in compost or manure with the soil and plant the crowns about 2 inches below the surface of the soil. Backfill and water well until established.
From Seeds;
You can start rhubarb seeds indoors in early spring or directly outdoors once the risk of frost has passed. If starting indoors, plant your seeds about 8-10 weeks before your last frost date. If starting your seeds directly outdoors make sure not to plant until all risk of frost has passed.
The seeds have a paper-like shell so to help speed germination soak the seeds in water for a few hours before planting. If starting indoors plant seeds in an organic planting mixture. Start by planting 2-3 seeds in a 2-3 inch pot and thin out to 1 when the seedlings are about 1 inch high. Keep the pots in a warm and sunny spot and make sure the soil stays evenly moist while making sure not to overwater. Transfer the seedlings to the garden on a cool or overcast day when the plants are about 4 inches tall and all risk of frost has passed. For the best success rate, make sure to harden the plants off before transferring them to the garden. Do this by moving the pots outdoors for a few hours every day starting about 7-10 days before transferring and increasing the amount of time they spend outdoors by an hour every day.
From Divisions;
It’s very easy to grow rhubarb from divisions of old plants. Ideally, rhubarb should be dug up and divided every 4 – 5 years or when you notice the roots getting old and gnarly or there is a hole in the center of the clump. This is best done in late winter or early spring while the plant is still dormant and before new growth starts or in the fall after the plant has gone into dormancy.
Using a spade dig about 8 inches into the soil and carefully dig around the root ball to free it. Once it is free on all sides, dig under the root clump and lift the root to free it. Locate the swollen buds on the top of the mass that indicate the growth points. Using a sharp, sterilized knife divide into sections about 3 – 4″ in diameter making sure that each section has at least one bud and a large root section.
Dig a new hole about 3 times the size of the root balls and about 4 feet apart to allow for spreading. Place some compost at the bottom of the hole and form a mound of soil about 2″ high. Place the section upright on the top of the mound spreading the roots down around the mound. Backfill the hole with soil making sure not to cover the buds and water thoroughly. Cover the surrounding soil with straw or mulch and water deeply once or twice a week or more in hot weather until the new plants are well established. If you’re dividing in early spring, you should start to see new growth in about 2-3 weeks. Resist harvesting stalks in the first year after transplanting. In the second year lightly harvest and by the third year, you can resume harvesting regularly.
Caring For Your Rhubarb Plant;
Your rhubarb plant will do best if you mulch it generously with straw and preferably manure to help retain moisture, keep down weeds, and help provide nutrients. Rhubarb is a heavy feeder so likes to have nutrient-rich soil to feed on. Keep the plant well watered, especially in hot weather. Be sure to remove the tall seed stalks as soon as they appear by cutting them off as far down to the crown as you can. If not removed the seed stalks will eventually flower diverting energy away from the edible plant stalks.
In the fall after the ground has frozen cover the plant with 2-inches of high-nitrogen compost to help prepare the plant for growth the following spring.
How To Harvest;
A mature rhubarb plant (3 years old) can be harvested about 3-4 times from spring to early summer when the stalks are 12-18 inches long. Resist harvesting any stalks during the first year after you plant or divide rhubarb to allow the plant to become established. Also, be sure to never harvest more than 2/3 of the stalks at a time or the plant won’t have enough reserves to live on.
The best way to harvest rhubarb is to grab and hold it firmly at the base of the stalk and twist & pull until it comes free. Never cut the stalks as this could leave the plant susceptible to crown rot caused by water seeping into the cut.
Caution;
While the stalks are edible, the leaves of the rhubarb plant are toxic. They contain oxalic acid which can be harmful if eaten so always cut off the leaves & discard them in your compost bin. Don’t feed them to animals either as eating them could make them sick.
How To Store;
If you’re not using them immediately wrap the unwashed stalks in plastic and put them in the fridge. They will keep fresh for up to a week.
Now that you’ve successfully learned how to grow rhubarb, you’re going to need some great recipes to use it all up. Check out this delicious and easy Freezer Rhubarb Jam.
Karen
