Rhubarb takes up little space and is very popular with hobby gardeners. We show you how to properly plant, fertilize and harvest rhubarb.
Rhubarb (Rheum rhabarbarum), a member of the knotweed family, is one of the first vegetables of the year. Although rhubarb is popularly referred to incorrectly as a fruit, which can be traced back to its use in desserts, it is actually a petiole vegetable, such as chard or celery. Due to the current return to old varieties and regional reference, rhubarb has experienced a real boom in recent years.
Rhubarb tastes delicious in many varieties and is wonderful to grow in your own garden. The perennial plant can be harvested again every year without much effort. Their strong scents also protect them from predators, which makes successful cultivation even easier. Since rhubarb is cold and frost-resistant, it is also ideal for cooler gardens. In the following we will introduce you to everything from rhubarb varieties to correct planting and care to harvesting.
Rhubarb: origin and history
Rhubarb originally comes from the Himalayas and parts of China. Related plant species such as Tibetan rhubarb (Rheum officinale) and palmate rhubarb (R. palmatum) were used in traditional medicine as medicinal products. Here, not the stems were processed, but mainly the underground sprouts. The vegetable rhubarb found its way via Central Asia to England, where it has been cultivated since the 18th century. Rhubarb is still very popular in England today, leading to names such as the Rhubarb Triangle, a rhubarb stronghold in West Yorkshire. The plant then reached Germany, Austria and Switzerland via England.
Rhubarb Varieties
The varieties of rhubarb are distinguished either by the time of harvest (early, middle and late varieties) or by the color of the stalks. In general, green varieties are more productive, but the red-fleshed varieties have a milder taste and a higher oneattributed ornamental value. There is a vast selection of varieties. You can find an overview of the best-known here:
- 'Champagne': Early and high-yielding variety
- ‘Elmsblitz’: Old and dark red rhubarb variety with a low oxalic acid content
- 'Elmsjuwel': Stem and flesh red with low acidity; especially recommended for people sensitive to oxalic acid; medium yield
- 'Frambozen Rood': Late and aromatic variety with red stems and green flesh; Because of the scent, Frambozen Rood is also known as strawberry or raspberry rhubarb
- ‘Gigant’: Very vigorous variety with green stems and high oxalic acid content
- 'Goliath': Largest red-stemmed and green-fleshed rhubarb variety with stems up to 100 cm; during flowering the plant reaches up to 180 cm; a high quality and very productive variety
- 'Holsteiner blood': Very well-known variety with the stems being red at the end; the variety is known for its mild flavor and high sugar content
You can find a comprehensive overview of rhubarb varieties in this special article.
Plant Rhubarb
The easy-care rhubarb is a disease-resistant and worthwhile plant that should not be missing in any garden. It likes it damp and prefers a rather harsh climate, since a long enough cold period is a guarantee for a good yield. Rhubarb prefers a sunny, sheltered spot in the garden. The soil should be well drained and ideally have a pH of 7. Since rhubarb multiplies rapidly, you should calculate about one square meter of space per plant. Either root pieces of older plants or container plants that can be planted in April or autumn are planted in autumn. As a temporary solution, rhubarb can also be cultivated in pots, but you should make sure that the planter is large enough and that the soil is permeable. Our Plantura organic tomato & vegetable soil provides your rhubarb with optimal nutrients and is also completely peat-free.
You can find detailed instructions on planting rhubarb here.
Propagating rhubarb
You can propagate rhubarb either by division or by seed. Division is a very simple form of propagation. The rhubarb is first dug up. Then, using a digging fork or spade, carefully divide the rootstock into pieces weighing about one kilogram(“lump”). Make sure each "clump" has at least one shoot tip. Chopping through roots is often essential for division. The separated pieces are then planted in nutrient-rich soil such as our Organic Tomato & Vegetable Soil and watered well.
The second way to propagate rhubarb is to sow seeds using purchased seeds. Sow them in May in the cold frame. However, rhubarb propagated from seeds can vary greatly in taste and color, so "cloning" a rhubarb plant by dividing it is better suited for self-propagation.
You can find more information on propagating rhubarb here.
Caring for Rhubarb
In itself, rhubarb does not require a lot of care. Here we have summarized all the important information about caring for the plant for you.
Fertilize rhubarb
Rhubarb loves nutrient-rich soil enriched with compost. It is sometimes difficult to add compost to the mature perennial, so it is important, especially when planting, to enrich the soil with sufficient compost or primarily organic slow-release fertilizer beforehand. Our Plantura organic tomato fertilizer is such a long-term fertilizer with a three-month effect and contains all the necessary nutrients for a rich rhubarb harvest. The best time for further fertilization is after the harvest in June or July. You can find out more about the ideal fertilization of rhubarb here.
Pour the rhubarb
When watering the rhubarb, you should only make sure that it is neither too dry nor too wet. Rhubarb does not tolerate waterlogging very well. Some sources recommend removing the buds, which can also be consumed. However, it is not absolutely necessary to remove the flowers.
Pests and Diseases
In general, rhubarb has little disease susceptibility. The location of the plant should be changed every 10 years. Here it is advisable to plant young plants or, if necessary, to cut off young rhizomes of the mother plant. In very heavy and moist soils there can sometimes be problems with rot. In general, in such a case, the soil should be loosened up with plenty of compost before planting. No scissors or knives should be used when harvesting, as this can transmit diseases.
Harvest Rhubarb
Rhubarb is generally not harvested until the second year after planting. Harvest time begins inApril and lasts until St. John's Day (June 24). After that, you should not harvest your rhubarb for two reasons: first, to give the plant a rest and recovery period, and second, because of the increase in oxalic acid levels. People suffering from iron deficiency and those suffering from gout, rheumatism, arthritis or kidney disease should generally be cautious about consuming foods containing oxalic acid such as rhubarb.
You don't cut the rhubarb stalks, but carefully twist them out of the ground. Otherwise the plants can rot at the interfaces or get other diseases. About three stalks can be harvested from each mature plant per week without causing lasting damage to the plant. Although the stalks stay moist in the fridge for about a week, only the amount that is actually needed to protect the plant should be harvested fresh. You can remove the leaves of the rhubarb immediately after harvesting, as they have a high oxalic acid content. If the leaves are not removed, the rhubarb stalks will lose water and become limp quickly.
You can find more detailed information on harvesting rhubarb here in our special article.
Force and Bleach Rhubarb
The so-called forcing and bleaching is a way of bringing the rhubarb harvest forward by up to three weeks. Usually at the end of February, a forcer is placed over the rhubarb that is still in the ground. The so-called propulsion pot or bleaching pot is usually a slim terracotta vessel with a removable lid. Since the propellant pot catches the first rays of the year and stores the heat inside for a few hours after sunset, the rhubarb begins to sprout early in the year. The darkness further accelerates the growth process as the plant shoots up in search of light. The gardener can check the growth progress through the removable lid.
Click here for more details on forcing and bleaching rhubarb.
Preserving Rhubarb
Rhubarb sticks contain a lot of vitamin C and taste great in desserts, cakes, juices and jam. If the rhubarb harvest turned out to be a bit too rich, there are ways to preserve it.We have put together everything you need to know about freezing and preserving rhubarb so that you can enjoy your tasty rhubarb harvest for as long as possible.
Freeze Rhubarb
Wash the stalks well with water and peel the rhubarb. It is then advisable to cut the sticks into smaller pieces and place them in a suitable container for the freezer. So you can still enjoy your rhubarb harvest at any time. The frozen pieces are particularly good for making compotes or cakes later.
Preserving rhubarb
If you cannot process your rhubarb in time or want to preserve it for later consumption, you can boil it down to make compote or jam. Wash and peel the rhubarb and cut it into slices about one centimeter wide. Before actually cooking, the rhubarb should be placed in boiling water for about five minutes to reduce the oxalic acid content.
Basically, rhubarb can be boiled down in two ways. Only in water or as a sweet alternative with sugar and without water. For both variants, cook the rhubarb to the desired consistency, which can often be as little as ten minutes. After cooking, it is filled into sterilized jars while still hot and these are tightly closed. Place the jars on their lids until completely cool. The preserved rhubarb will keep for several months in a dark place.
You can find detailed instructions for freezing and preserving rhubarb here.
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