Many hobby gardeners ask themselves what they should actually do with the rhubarb blossoms. Because the misconception that the plant becomes poisonous when it blooms still persists. We clarify whether the flowers of the Rheum rhabarbarum are actually poisonous or even edible and at the same time explain why cutting off the flowers is not recommended!
Flowering time of rhubarb
Basically, the rhubarb season ends on June 24th, because that is when the St. John's impulse begins. This is a second growth spurt, during which the plant gathers strength for the winter and the following year. The first flowers often form at this time if the plant has previously been exposed to a constant cold stimulus. This process is called vernalization and means that the rhubarb should be exposed to temperatures of a maximum of 10 °C for around 12-16 weeks. After this cold treatment, the plant flowers and forms a paniculate inflorescence with a multitude of cream-colored flowers.
rhubarb flowers
The rhubarb forms its flowers primarily to attract insects and thus promote their reproduction. The cream-colored rhubarb flowers have easily accessible pollen and particularly tasty nectar, making them particularly popular with bees and bumblebees. As soon as the Rheum rhabarbarum flowers, it attracts numerous insects and ensures food for them. The pretty rhubarb flowers are not only interesting for insects, because humans can also use them:
- are suitable for decoration
- Flowers are edible
- can be made into dishes
toxicity
Are rhubarb flowers poisonous?
Unfortunately, the rumor that the rhubarb becomes poisonous when it starts flowering persists to this day. This misconception is justified with the rising salary oxalic acid, which is lowest in May and April and highest from June. Oxalic acid is an odorless and tasteless substance that can cause problems in the human body:
- binds calcium and prevents iron absorption
- promotes rheumatism and kidney stones
- bad for the joints
- attacks tooth enamel
However, it is often ignored that the oxalic acid is mostly in the leaves and in the bark of the stems. However, the concentration of oxalic acid in the other parts of the plant and thus also in the rhubarb blossoms is high harmless. Apart from that, a toxic effect from the consumption of rhubarb is almost impossible. According to scientists, poisoning occurs from the consumption of around 5000 milligrams of oxalic acid. If you consider that 100 grams of rhubarb contains about 150 to 500 milligrams of oxalic acid, the calculation is as follows:
- an adult (around 60 kg) would need to consume around 36 kg
- a child (about 20 kg) would have to eat about 12 kg
edibility
Rhubarb blossoms are edible!
The harvested flowers can be distributed around the house for decoration or processed into tasty dishes. The taste of the flowers is similar to that of broccoli or cauliflower, although the taste is usually described as a little more sour. The flowers can be processed into a wide variety of dishes, although it is advisable to experiment a little. Among other things, the following dishes can be prepared from the rhubarb flowers:
- baked rhubarb flowers
- filled rhubarb blossoms
- baked rhubarb blossoms with tomato sauce
- sweet dishes
Store rhubarb blossoms
Freshly harvested rhubarb is best processed or preserved directly. Because the shelf life of Rheum rhabarbarum is limited to a few days. For short-term storage, it is advisable to wrap the plant parts in a damp cloth and store them in the refrigerator. It is not recommended to store the flowers in aluminum foil or in aluminum containers. Because the flowers contain, although in a harmless concentration, oxalic acid, which reacts with aluminum and dissolves it.
Remove rhubarb blossom
Cut or break out?
A rhubarb that is in bloom is extremely decorative thanks to its cream colored flowers. However, it is advisable to remove the rhubarb blossom. Because this means that the plant more energy for the root ball and leaves. These are better supplied with nutrients, which in turn is reflected in an increased crop yield. But be careful: the flowers are never cut off, but carefully broken out! Because the plant is not injured so badly by breaking it out and mold formation on the cut edges is also prevented. Once the inflorescences are fully mature, the flowers are burst out as follows:
- Grasp the flower with your fingers
- preferably at the base of the stem
- Rotate the flower slightly clockwise
- then water extensively
notice: If you are not aiming for the maximum yield, but just want to harvest a few stalks of rhubarb every now and then, you can leave the flowers on the plant without hesitation!
growing rhubarb blossom