This sounds like the perfect clickbait for any gardening channel! But behind these sensational headlines lies a crucial botanical turning point in June. In June, tomatoes switch from pure growth to flower and fruit production.
If you give them the wrong fertilizer now, only the leaves will grow, but you’ll hardly see any fruit. If you give them the right thing, the harvest will explode.
Here’s the secret (and scientifically sound) roadmap for your tomatoes in June:
- The secret in June: Less nitrogen, more potassium and phosphorus!
Many people reflexively reach for classic nettle manure now. Stop! Nettle manure is extremely high in nitrogen. That’s great for leaf growth in May. In June, however, too much nitrogen causes the plant to bolt – it produces huge green leaves but hardly any flowers.
This is the real game-changer:
Comfrey manure: The absolute star in June. Comfrey (a wild plant) contains huge amounts of potassium. Potassium transports energy directly to flower and fruit development, making the tomatoes flavorful.
Organic tomato fertilizer or sheep wool pellets: If you don’t want to make manure. These fertilizers release nutrients slowly and have the perfect ratio for the fruiting stage.
Rock dust: A handful worked into the soil around the plant provides essential calcium. This prevents the dreaded blossom-end rot (black spots on the bottom of the tomatoes).
- The “result doubler”: Regular pruning and shaking
Fertilizer alone is useless if the plant’s energy is wasted. In June, you need to do two things:
Pruning: Consistently remove the small suckers that grow in the leaf axils. They only steal energy from the plant that it needs for the main fruit.
The “Bumblebee Method”: Tomatoes are self-pollinating. If it’s windless in the greenhouse or on the balcony, the blossoms often don’t pollinate and fall off. Gently shake the plant every morning in June. This will cause the pollen to fall onto the stigma – and every blossom is guaranteed to become a tomato.
Cheat Sheet for June Success
Measure Why in June? Effect
Potassium-rich fertilizer (e.g., comfrey) Promotes fruit development instead of leaf growth More and sweeter fruits
Rock dust/Calcium Protects against cell damage at the base of the fruit No blossom-end rot
Morning shaking Replaces the wind/bumblebee Maximum pollination rate
Are you growing your tomatoes in a greenhouse, outdoors, or on a balcony this year?