Rhubarb is one of the perennial vegetables, but it is mainly used in desserts and cakes. The fleshy stalks are harvested, but not the blossoms, leaves or fruits. Rhubarb (Rheum rhabarbarum) begins to sprout in early spring, there is even the possibility to help. But just as early as the harvest begins, it ends again. Rhubarb harvest time is over before summer begins.
Table of Contents
In the first year after planting, no stalks are harvested, instead the rhubarb is well cared for. The plant thanks this consideration with vigorous growth. A larger harvest can be expected in the following season. But even in the second year, consideration is given to the young plants. Only a few, particularly strong stalks are harvested and the rhubarb harvest ends earlier. Traditionally, the harvest time is from April to June 24th. But this is not an absolute deadline. Rheum rhabarbarum remains edible until the end of June/beginning of July.
To ensure that the plant is not damaged, the following must be observed:
- Stalks are mature when they are smooth and the leaves are spread
- unscrew at the base
- Cut off the leaves and stems
- if processed immediately, the stalk can also be peeled on site
- Plant residues can be left on the rhubarb bed as mulch
- remove flowers
- don’t harvest too many stalks
- the plant must have enough leaf mass for further growth
- about two thirds of the leaves remain
- Fertilize and water generously throughout the summer
- Earlier harvesting with overturned buckets or driving bells
- Harvested stalks stay fresh in the fridge for a long time when wrapped in damp tea towels
An important reason why Rheum rhabarbarum is no longer harvested after a certain point in time is the oxalic acid it contains. It is harmful to health and can lead to poisoning in higher concentrations. People with kidney stones, an iron deficiency or problems with the mineral balance are particularly at risk. Oxalic acid binds minerals such as calcium or magnesium, the resulting complex compounds can no longer be broken down by the body and it can no longer absorb the minerals. In addition, the acid attacks the tooth enamel.
In order to reduce the oxalic acid content, it is important to harvest at the right time and use the right harvesting technique. This includes:
- Cut off the leaves and do not eat them
- there is also a lot of oxalic acid in the white stalk, remove this as well
- peel stems
- no late rhubarb harvest
- the longer rhubarb grows, the more oxalic acid it contains
- Do not eat Rheum rhabarbarum raw, always boil it, discard the cooking water
- do not eat too much rhubarb at once
- possibly eat together with dairy products
- Oxalic acid binds to the calcium and not to other nutrients in the body
Another reason why you shouldn’t harvest rhubarb later in the year is because of the plant itself. It needs a period of time to regenerate and grow. The longer the plant is allowed to grow, the stronger it will become and the larger the next crop will be. For this reason, only about a third to a maximum of half of the available stalks are harvested each year. In addition, the flowers are broken out so that the plant is not additionally weakened by the formation of flowers and seeds.
While rhubarb tastes tart and fruity in spring, the stalks become increasingly woody and fibrous over time. So it’s not worth harvesting rhubarb later than early summer, as it simply doesn’t taste as good then. If rhubarb is to be on the menu more often, it makes more sense to preserve it by boiling it down or to mix it with strawberries to make jam. Then it can be enjoyed all year round without sacrificing taste.