Thanks to their hermaphrodite flowers, tomato plants fertilize completely independently outdoors. However, where there is no wind and busy insects, a little help is needed. This is how you promote lush fruit setting in the greenhouse and on the windowsill.
How to fertilize tomato plants manually?
To successfully fertilize tomato plants, provide air circulation through ventilation and support pollination with daily shaking, an electric toothbrush, a soft brush or manual fertilization at temperatures below 30 degrees Celsius and humidity below 80 percent.
No tomatoes without pollination
No matter how lovingly the hobby gardener cares for his tomato plants, he will not harvest any fruit without successful fertilization. Only when pollination takes place within the flowers will the desired fruit set develop. The natural process works that simply:
Tomato plants are hermaphrodite. A flower contains both the female pistil and the male pollen. In the open air, the wind or insects ensure that the pollen reaches the pistil. Botanists call this process 'pollination'. The pollen now fertilizes the female egg cell and thus initiates the growth of the fruit base, from which a magnificent tomato develops.
The tomato plant simply throws off all unpollinated flowers because it doesn't want to invest any more energy in them. A lush bloom alone does not guarantee a rich harvest.
How to help the fruit set along the way
As a self-pollinator, a light breeze is enough for a tomato plant to distribute the pollen to the flowers and ensure successful fertilization. Busy bumblebees and bees also reliably pollinate in the open air. Since both factors are missing in the greenhouse and on the windowsill, the hobby gardener acts as a substitute pollinator. This is how the plan works:
- promote air circulation through regular ventilation
- From the beginning of flowering, shake the tomato plants daily around midday
- Use an electric toothbrush to vibrate the tomato flowers so that the pollen falls out
- paint a soft brush over the flowers
- perform manual insemination on several days in a row
However, efforts to manually fertilize tomato plants only have a chance of success if temperatures fluctuate below 30 degrees Celsius. In addition, humidity plays an important role. If the value is over 80 percent, the pollen clumps together. Pollination is therefore impossible. A thermometer and a hydrometer are therefore part of the standard equipment for the tomato gardener.
Tips & Tricks
If there is the desired number of fruit sets on a tomato plant, all remaining flowers are broken off. In this way, the plant saves energy early on, which it can only invest in plump, voluminous fruits.