Marigolds are considered to be a tomato's best friend, but what if they're secretly killing your tomatoes?
In 2022, the Journal of Agricultural Science shocked gardeners: certain varieties of marigolds (for example, Tagetes erecta) produce terpenoids that slow down the growth of tomatoes by 40%.
The famous agronomist Nikolai Kurdyumov warns in his book “Smart Garden”:
"Marigolds are not a panacea. Their roots can be poisonous to nightshades."
A real example: Dmitry from Voronezh lost half of his tomato harvest after planting marigolds in his garden “for beauty”.
A soil analysis showed that the flowers had depleted the nitrogen, making it unavailable to the tomatoes.
Scientists at the University of Florida have found a solution: plant low-growing marigolds (Tagetes patula) 2 feet (60 cm) away from tomatoes. Their roots produce fewer toxins, but still repel nematodes.
The blogger "Tomato King" conducted an experiment: he divided a bed with a chain-link fence, planting marigolds on one side and tomatoes on the other. The result? The nematodes disappeared, and the harvest increased by 25%.
"The secret is to limit root contact," he explained.
Another life hack from Japanese farmers: cut marigolds in the budding phase and use them as mulch.
This way they repel pests without competing for food. But there are varieties that should not be planted next to each other at all.
Lemon Drop marigolds, according to Organic Farming Magazine , produce alkaloids that cause leaf chlorosis in tomatoes.
But "Vanilla" and "Red gem" are safe. Feedback from the "Tomatogrody" chat:
“I transplanted marigolds to the edge of the greenhouse - the fruits became larger!”
