Parsley and dill have become bitter? The culprit may be geosmin, an organic compound that accumulates in greens if root vegetables were grown in the garden before them.
A University of Reading study has confirmed that carrots, beetroot and radishes release terpenes (aromatic substances) into the soil, which affect the biochemistry of subsequent crops, increasing bitterness.
Root crops, especially carrots and beets, release secondary metabolites into the soil during growth — chemical compounds that protect them from pests. These substances remain in the soil for up to 2–3 months and:
1. Crop rotation according to the rules
Plant greens after crops that remove terpenes from the soil
2. Soil detoxification
3. Express method for emergency cases
Gordon Ramsay warns on MasterChef :
"Bitter greens will ruin even the most expensive steak! Check the beds as you check meat for freshness. Before planting, rub a lump of soil in your hands - if it smells moldy or damp, the soil is not suitable."
Agronomist Maria Sokolova ( Green Patrol channel) advises:
"After harvesting the root crops, water the bed with horsetail infusion (500 g of grass per 10 l of water). It contains silicic acid, which binds terpenes."
Onions and garlic - their phytoncides inhibit the growth of parsley and dill.
Potatoes - increases the risk of soil contamination with nematodes, which make greens tough and bitter.
Sunflower - secretes allelopathic substances that slow down the development of umbelliferous crops.
Bitter greens are not a death sentence! Proper crop rotation, green manure and natural fertilizers will help to "reboot" the soil. And remember: the soil, like good wine, requires time and proper care.