Growing rhubarb—in the right location, this hardy plant can thrive for decades
While growing rhubarb from seed to harvestable maturity takes time, once it’s established, you can enjoy early spring harvests for decades to come. This low-maintenance and hardy garden plant rewards even the laziest gardeners.
Considering how easy it is to care for, the crunchy rhubarb is an underrated home garden plant. Growing rhubarb requires a bit of patience: you should allow it to root and develop undisturbed. But after that, this bountiful plant rewards even the laziest gardener. It yields abundant harvests and thrives in favorable conditions for decades.
Rhubarb has long been popular as a striking ornamental plant. In ideal conditions, its colorful stalks can rise nearly to the height of a grown man, and its large, lush green leaves create an impressive backdrop for more delicate plants.
Growing rhubarb—tips for success
Soil requirements
The vigorously growing rhubarb requires fertile, moisture-retaining soil.
Light requirements
Plant rhubarb in full sun. It can tolerate partial shade, but the yield may not be as plentiful.
Growing rhubarb—from seedling to lush growth
Growing rhubarb from seed to harvestable maturity takes patience. It can be grown from seedlings, pieces of rhizome, or seeds. Sow your seeds in a bed or box in spring, and thin the seedlings to about 20 centimeters apart.
The easiest way to get started is to get a seedling and plant it in the ground in spring or autumn. Plant rhubarb in full sun or partial shade, in deep, fertile soil with adequate moisture. In dry conditions, the plant struggles and may flower prematurely; in overly wet conditions, the root system suffers. Leave at least one meter of growing space around the rhubarb seedling.
During the first year, the seedling should be watered and fertilized regularly. Later on, rhubarb benefits from annual fertilization and watering, especially if the soil is prone to drying out. Mulching reduces the need for watering. Rhubarb has dense growth which effectively suppresses annual weeds, but perennial weeds may still be a problem.
Which plants to pair with rhubarb
- Strong-growing herbs that appreciate moist soil, such as lovage, mint and sweet cicely [in Finnish] can be grown in the same bed as the broad and leafy rhubarb. Just make sure to leave plenty of space between the plants.
- It’s also worthwhile to try planting various perennials in the gaps in the rhubarb. A good example is oriental poppy [in Finnish].
- Early-flowering small bulbs, as well as wood anemone [in Finnish], bring spring blooms to the bed. You can also plant them near the roots of the rhubarb. The same applies to ramsons [in Finnish].
Watering
Make sure your rhubarb is watered appropriately and remove flower buds from small plants. Large, healthy rhubarbs can support both flowers and harvest.
Fertilization
In spring, fertilize your rhubarb with organic matter such as compost, grass clippings, or well-rotted horse manure. Leave any fallen leaves to decompose in place.
Rhubarb can tolerate acidic soil and will often grow and thrive even if fertilization is neglected. However, adding compost or other organic matter can encourage lush growth.
Dividing the rhizome
Renew your plant when its vitality starts to diminish. You can do this by dividing the root ball into sections, each with roots and at least one or two strong buds. You can also take a division from the side of the rhizome without lifting the entire plant from the ground.
A division must have at least one bud from which new growth can begin.
Rhubarb flowers
Rhubarb flowers so impressively that it can be a shame to remove its flower stalks, even if the flowers slightly reduce the yield. Early summer pollinators also appreciate rhubarb flowers. Older rhubarb plants are the most inclined to flower. The flowers of the ‘Victoria’ variety, common in Finland, are greenish-white, while, for example, the German variety ‘Emblitz’ has beautifully red flowers.
Harvest
In the year it is planted, allow your rhubarb to grow undisturbed and to gather strength in its roots. Rhubarb needs a couple of years before it starts to produce proper yield, so do not harvest during the first or second year.
Begin harvesting only in the third year after planting, once or twice a week, a few stalks at a time. Harvesting too early can weaken the plant excessively, to a point where it can no longer recover. Remove the stalks by pulling, and leave enough stalks behind for the plant to gather strength for the next year. The harvest season ends around the end of June.
If you remove the flower stalks from your rhubarb, it will redirect its energy to growing the roots and next year’s harvest instead of flowering and seed development.
When harvesting rhubarb, remove the stalk by twisting it off rather than cutting with a knife. This allows you to use the entire leaf stalk and no stump will be left to rot at the base of the plant. Leave some foliage for photosynthesis; do not harvest all the stalks, even from a large plant. Pulling all the stalks can drain the plant’s energy and cause even an old rhubarb patch to wither.
Use only the leaf stalks of rhubarb; the leaves are poisonous due to their high oxalic acid content.
Forcing
An old method for getting tender rhubarb with a delicate flavor is to force the stalks in complete darkness. Place a large clay pot, barrel, or black bucket over the emerging rhubarb shoots as soon as they appear from the ground in early spring. This trick tenderizes the stalks and reduces their oxalic acid content. Use this method for large plants, and do not force the same plant every spring.
Rhubarb varieties
Rhubarb varieties differ in stalk color, oxalic acid content, sweetness, flowering tendency, and how early they produce harvest. Red-stalked varieties have more anthocyanin than green-stalked ones. The red varieties are popular for their color, even though they produce lower yields.
Example varieties:
- ‘Victoria’ (‘Queen Victoria’): A traditional, particularly hardy and productive variety from 1837. The reddish stalks are green inside. Being high-yielding, it is likely the world’s most popular rhubarb variety.
- ‘Sanvitos Red’, ‘Raspberry Red’, and ‘Red Champagne’: The leaf stalks, rich in anthocyanin, give dishes a red color.
- ‘Emblitz’: Contains less oxalic acid than other varieties, making it a safe choice for people who use a lot of rhubarb. Getting too much oxalic acid can worsen conditions like gout.
- ‘Sanvitos Summer’ and ‘Livingstone’: Recommended for continuous harvesting throughout the season, where stalks are harvested a little at a time.
Did you know?
- In China and Mongolia, where many rhubarb species grow wild, dried and ground stalks of the plant have been used as a laxative for thousands of years.
- Rhubarb can grow as high up north as the Arctic Circle, and in Finland, it has been cultivated for consumption since the 1700s. However, it didn’t become widely used until the 1900s when sugar, used in tart rhubarb dishes, became more readily available.
- Rhubarbs have been gathered into a gene reserve collection, which ensures the preservation of their diversity.
