If you have parsley growing in your garlic bed, dig it up immediately!
Agronomist Larisa Semenova conducted an experiment: garlic planted next to parsley produced 50% fewer heads, and 30% of the harvest rotted due to fungus.
"Parsley roots secrete allelopathins, substances that inhibit the growth of their neighbors," explains Semenova. "The garlic weakens and becomes a target for fusarium."

Olga from Tver faced this problem:
"A month after germination, the garlic began to turn yellow. It turned out that the parsley in the neighboring bed was to blame."
Replace parsley with cilantro: its essential oils repel onion flies, and the roots do not compete for nutrients.
“Now I plant garlic and cilantro together – both grow like crazy!” boasts summer resident Ivan.
MSU scientists added: parsley draws nitrogen from the soil, which is necessary for garlic to form large heads. If they are adjacent, the soil is depleted in 2-3 weeks. The solution?
Sow mustard between them - it not only saturates the soil with nitrogen, but also suppresses the growth of weeds.
“Mustard is the best ‘mediator’ for garlic,” confirms agronomist Mikhail Vorobyov.
Here is another enemy of garlic - strawberries. Its roots secrete acids that slow down the development of cloves.
“I used to plant garlic next to strawberries to save space, but now I keep them at different ends of the garden,” advises gardening blogger Anna.