Tomatoes are an integral part of summer salad. But if suddenly fewer fruits ripen, you should help. We explain when you should pollinate the tomatoes and what tools you can use.
Do tomatoes need to be pollinated?
Like many other crops, tomatoes need to be pollinated in order to produce abundant fruit. Bumblebees, bees and other insects collect nectar and pollen, transferring some of the pollen from one plant to another or between the flowers of a specimen.
Are tomato plants self-pollinators?
Diemost types of tomatoesBut they don't just have to rely on pollinators - every flower has a pistil and pollen sacs. The pollen sacs are opened after the ripening period has ended and the wind carries them in all directions. Some of it gets into other tomato flowers and fertilizes them.
However, there are also varieties that cannot fertilize themselves. They definitely need the help of pollinating insects or humans to take over the task.
In what cases do tomatoes need to be pollinated?
These pollination options are usually possible when the plants are growing in the garden. However, the small vegetable garden on the balcony attracts significantly fewer pollinating insects - on the one hand because there are significantly fewer pollinators in big cities due to noise, air pollution and a lack of food. On the other hand, because the balcony offers protection from the wind and thus prevents the spread of pollen.
The situation is similar in the greenhouse, where the plants cannot be pollinated. If you don't do it yourself, you'll have to expect lower yields and significantly fewer ripe tomatoes. Because only the pollinated flowers bear fruit.
When do you have to pollinate tomatoes?
The optimal time depends on several factors. First and foremost is the humidity. If it is over 60%, the pollen sticks to the sacs and cannot be released even when the flower is shaken. So it's best to choose a week when it doesn't rain.
Heat and long dry periods can also have a negative impact on pollen germination.
The best time to fertilize tomatoes is in the morning.
Pollinate tomatoes: This is how you can attract bees and bumblebees to the balcony
In the garden, pollinating insects are attracted by the diversity of species. But on the balcony, where space is limited anyway, creativity is particularly important. Choose plants that provide food for bumblebees and bees and that the insects like to fly to. These are, for example:
- lilac
- Clematis
- Lavender
- Beeweed
- Vanilleblume
- Margerites
If you have a large roof terrace, you can also install a bumblebee box. This gives the insects space to nest. It is best to assemble the box before the flowering period begins. The bumblebees nest inShadows and the insect hotelFill with dried moss and cover with hay. Only use natural materials that have not been treated with chemicals. Once set up, the insect hotel should stay in place throughout the gardening season.
Alternatively, you can pollinate the tomatoes yourself. There are different methods that we list below.
Pollinating the tomatoes: In the greenhouse, pollination without bees is an option
So for now: It is of course best if the tomatoes are pollinated by bees and bumblebees. However, this is not always possible. It is still worth ventilating the greenhouse as often as possible. If that doesn't help, then pollination by hand is an option. There are three variants in this regard:
Aid: electric toothbrush
The so-called trilling of tomatoes imitates the natural pollination carried out by bumblebees. The insects' wings trigger vibrations that release the pollen. This method is particularly effective with self-pollinating tomato varieties. This allows the pollen to quickly reach the pistil of the same flower and it is fertilized. But you need tools. An electric toothbrush is best. Proceed as follows:
- First turn the toothbrush on to a low setting.
- Then place the toothbrush directly above the first opened flower.
- Repeat the process for all other flowers, ideally trilling the tomatoes every morning.
Pollinating tomatoes with a brush: method that is ideal for the vegetable garden on the balcony
Another tool that is ideal for pollinating crops on the balcony or in a small greenhouse is the brush. This variant is an option if you only have a few tomato plants. Otherwise it is too time-consuming. Proceed as follows:
- First paint with a soft brush (clean and dry) over the pollen sacs and then over the pistil of a flower.
- Repeat the process with the other flowers too. You can also pollinate different flowers alternately.
- Do not clean or wet the brush in between. Only at the end clean the brush and let it dry.
- Repeat the process every morning.
Why should you shake tomato plants?
Shaking the tomato plant releases the pollen and imitates wind movement. This allows pollen to travel from one plant to the next and pollinate them. If you have a tomato variety that cannot self-pollinate, then you can use the third method – namely “shaking tomato plants”. Proceed as follows:
- Shake the potted plant in the morning.
- Use gentle movements to hold the individual stems very carefully with your fingers and shake them back and forth.
- Repeat the process every morning.
How to cross tomato plants?
Shaking is a good option even if you have different types of tomatoes and want to cross them. The ultimate goal should be a new variety that combines certain characteristics. For this purpose you need a polytunnel for tomatoes. Then the plants are divided into two: the first will take on the role of the mother plant, the second will release the pollen. An important prerequisite for success is that the flowers of the two plants have not yet opened.
First, the anthers of the mother plant are cut off, then the emasculated flowers are marked. Then the pollen is collected from the father plant. It's best to wait until the pollen sacs mature and open and then shake the pollen onto a dark plastic bag. The flowers of the mother plant are then rubbed onto the bag and fertilized. If they after about seven to ten daysbear fruit, then the crossing was successful.
If you want to pollinate your tomatoes, you have different options to choose from: attract pollinating insects, pollinate the plants yourself with a brush or toothbrush, or shake the vegetables.