The tuber has been cultivated in Europe since at least the 16th century. Lovers of this tuber appreciate it above all for its spicy, radish-like aroma. In addition, the concentration of healthy ingredients is considerable, which makes kohlrabi one of the healthiest types of vegetables, rich in vitamins and fiber. The different varieties only differ in colour, there are no noticeable differences in taste. This guide tells you when you should harvest the kohlrabi.
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Recognize harvest maturity
Not only the tubers of the kohlrabi ( Brassica oleracea ) are edible, but also the tender heart leaves. They can be planted in spring and even in summer. The ripening and harvest times differ from each other because they depend on the time of sowing or planting and of course the respective variety. Outdoors, it can be sown at temperatures as low as ten degrees.
The part of the kohlrabi that is suitable for consumption, the so-called tuber, develops from a thickening of the above-ground shoot axis. It gets thicker as it matures, until it finally forms a large tuber ready for harvest. All kohlrabi varieties ripen unevenly, so they can be harvested in several passes. Most kohlrabi varieties are ready to harvest when they are about the size of a tennis ball, with the exception of larger varieties such as ‘Super Schmelz’, whose bulbs can weigh up to eight kilograms. This circumstance should be taken into account both during sowing and harvesting.
The best time to harvest kohlrabi
It usually takes about eight to twelve weeks from sowing to harvest. There is no specific harvest time because, as already mentioned, it depends on the time of sowing and the variety.
- Harvest times from April/May to October/November
- Leaves should still be light green or purple when harvested
- Withered leaves, signs that the optimum harvest time has been exceeded
- Harvesting too late leads to losses in taste and quality
- the typical spicy taste decreases significantly
- Consistency of the tubers woody and hardly edible
- Harvesting too early is also not recommended
- Kohlrabi should definitely be fully grown and of normal size
- Harvest burst kohlrabi bulbs immediately
- Kohlrabi varieties for winter storage, ideally harvest on a sunny autumn evening
- The nitrate and water content in the vegetables is then at its lowest
- this enhances the taste of the kohlrabi
- Harvesting should be complete before the first frost
Harvest times of the most popular kohlrabi varieties
Red-Blue Blaro:
Dark blue bulbs, spicy taste, Harvest: April to September
Blue Delicacy:
Blue-violet tubers, delicately spicy taste, Harvest: July to September
White delicacy:
White tubers, delicately spicy taste, tends to become woody, harvest time: July to October
White Lanro:
White bulbs, delicate taste, harvest time: June to October
Super melting:
White to light green tubers, delicate taste, not woody, harvest time: August to October
Giant kohlrabi ‘Kossak’:
Particularly large white tubers, buttery taste, Harvest: June to November
Harvest kohlrabi correctly – instructions
Kohlrabi is actually a biennial plant. In the first year, the tuber, i.e. the kohlrabi, is formed and in the second year, the stalk with the branched inflorescences. The pods with the seeds later develop from these. If you want to harvest seeds, you should leave some stalks. You can harvest fresh tubers at any time, and most of the fruit harvested in autumn is stored as a winter supply.
- Simply lift individual bulbs out of the ground for immediate consumption
- Then remove the stalk and leaves and process accordingly
- Otherwise, cut off the tubers at the stalk
- Remove leaves except for short leaf ends to avoid damaging the tubers
- Leaf bases will soon fall off by themselves
- Leaves that are not removed will draw water from the kohlrabi
- This affects quality and durability
- Remove any dried or rotten parts
The young heart leaves should never be thrown away. They contain more vitamin C and minerals than the tuber itself and can be served very well in colorful summer salads, briefly blanched with other dishes, or prepared like spinach. If more tubers had to be harvested than can be consumed in the shortest possible time, they can be stored for some time, depending on where they are stored.
Proper storage
Only healthy and undamaged tubers should be stored. Late-ripening varieties have a much longer shelf life and can be stored than early ones. Tubers that are intended for storage should not be fertilized too much if possible.
Vegetables that have been over-fertilized with nitrogen do not keep for long and are not as healthy as plants that have been fertilized in a balanced way. Fresh kohlrabi can be kept for up to two weeks in the refrigerator, with the stalk and leaves removed, wrapped in damp kitchen paper. Without a moist wrapper, it dries out faster and keeps for a maximum of six days.
In frost-free rooms
- Longer storage in a cool but frost-free storage place
- Ideally, an unheated basement
- With temperatures of 2-4 degrees and humidity of at least 80 percent
- The metabolism of the tubers comes almost to a standstill
- This counteracts the formation and spread of mold and rot
- Durability is significantly reduced
Under optimal conditions, the fresh tubers can be stored for several months without any noticeable loss of taste or quality. Before storage, all stalks and leaves are cut off or twisted off. In the cellar they are then placed in crates or fruit trays with earth or damp sand.
In an earth rent
If you don’t have a suitable space, you can store the vegetables in a self-made heap. To do this, dig a pit of appropriate size at a slightly higher point in the garden. To protect against rodents, both the bottom and the side walls are lined with a fine-meshed, galvanized wire mesh.
A layer of dry walnut leaves can also help keep voles and other rodents away. This is followed by a layer of sand about ten centimeters high, on which the kohlrabi bulbs are placed. Finally, they are covered with a thick layer of straw and fleece. Wooden boards can be used as the top cover.
Conclusion
The kohlrabi is a typical German vegetable. Harvested at the right time and eaten fresh, it is at its tastiest and most aromatic. In terms of ingredients, they are even surpassed by the young heart leaves, because they are much more substantial. For these reasons alone, the tuber should not be missing in any garden.