Turnips and swedes
Brassica rapa / napus is of limited suitability for hydroponic self-sufficiency in a deep substrate system.
Why this crop makes sense
Weigh the growing period and space requirement against the crop’s storage value. The decisive question is not merely whether the plant grows hydroponically, but whether its edible yield, growing period, light requirements, workload and storage life suit the household.
System and root space
A deep substrate system is recommended. The root zone must remain evenly moist, well aerated and protected from light. Record the source water and nutrient solution; returns, pipes and reservoirs must remain accessible and easy to clean.
Suitable system pages: Ebb-and-flow substrate culture
pH, EC and climate
A cautious starting range is pH 5.8–6.5 and EC 1.5–2.2 mS/cm at 12–22 °C. These are not universal target values: cultivar, age, light, source water, temperature, measuring method and development stage may require adjustments.
Sowing and crop management
Plan turnips and swedes separately because their growing periods and space requirements differ considerably. A small preliminary trial checks germination and system performance. Space plants approximately 15–30 cm apart and regularly inspect root health, leaf colour, pests and uniform water distribution.
Harvesting and storage
Harvest when the swollen roots reach the size typical for the cultivar. For longer-term storage, keep them cool or ferment them. Process only healthy, clean plant parts and follow the food-hygiene requirements of the chosen preservation method.
Troubleshooting
- Tall, soft plants: check light levels, spacing and temperature.
- Leaf-edge damage or chlorosis: check not only EC but also pH, water hardness and nutrient formulation.
- Brown roots: investigate temperature, oxygen supply, hygiene and waterlogging.
- Uneven yields: compare flow rates, emitters, plant spacing and cultivars.