How Do You Pollinate Greenhouse Tomatoes?

While tomatoes are self-pollinating, they still thrive better with a bit of help from wind or bees. But in a closed environment that is a greenhouse, this can become tricky. 

So, how do you pollinate greenhouse tomatoes? Here are some useful strategies:

  1. Pollination by hand 
  2. Use bees
  3. Pollination spray
  4. Use the power of the wind
  5. Play some music

Each of these methods requires a specific technique that will make your results better. Let’s take a look at possible solutions, as well as some other fixes to common greenhouse tomato problems. 

How Tomato Pollination Works 

Tomatoes are self-pollinating to a degree, but the truth is that bees and wind make the yield a lot better. They have both female and male parts — the pollen needs to fall from ones to the others within the flower for the fruit to grow. However, this is often not the case. Tomatoes, like many other plants, work best when they have the support from bees. 

At the same time, tomatoes can’t be pollinated by honey bees. They need pollinators that provide light vibrations — so carpenter bees, bumblebees, and wind work. 

Tomatoes pollinated by bees have more vitamin C, and they end up heavier than others. There’s even research that states that tomato crops surrounded by flowery fields bring better produce than those that are not. This can help you understand just how important bees are to your tomatoes. 

But even with bees, heat can make your yield poor. If the temperatures are above 85°F (30°C), the pollen won’t be viable, and fruit won’t set. If it’s too humid, the pollen can turn sticky, and no amount of vibrations will work. If it’s too dry, the pollen from the male parts won’t stay on the female parts. 

Of course, this can depend on the type of tomatoes you have. For example, heirloom tomatoes are more fickle than hybrid types. Some varieties work well in the heat, like Solar Fire, while some prefer milder conditions. 

The important thing is to find the type of tomatoes that can thrive in the conditions you can provide. Check with an expert before planting. 

Pollination by Hand 

Pollination by hand has several methods. Most of these will work, providing that other conditions are met, but they require a bit more work. You have to work on each plant separately, and there isn’t a faster way of pollination by hand. 

Still, it works best for smaller greenhouses, since a larger one may require more workers and more time. 

Essentially, all methods of hand pollination rely on producing vibrations similar to those produced by natural pollinators. Let’s take a closer look.

  • Paintbrush Pollination. Replicating vibration that commonly happens in nature is simple with a paintbrush. Use a small paintbrush, preferably a soft one that’s commonly used by artists. The tip of the brush will vibrate in a similar way to the wings of a bumblebee, and promote effective pollination.

To do it, you have to lift the flower, but gently. Then, lightly move the brush on the petals. You should do this every two to three days, around noon. If you have several types of tomatoes in your greenhouse, clean the brush before moving from one type to the other to avoid cross-pollination. 

  • Finger pollination. This is similar to paintbrush pollination. Only this time, you would use your finger. Move it quickly, similar to what you would see in a bee movement. The flower should vibrate and move enough to enable the pollen from male to female parts. This may be a bit harder, but it’s also nice if you have a smaller greenhouse. 
  • Electric toothbrush. You can make the process easier by simply using an electric toothbrush. It will help you do the job quickly, and it won’t cause you much trouble. Make sure that the toothbrush is gentle and that you don’t shake the flower too much. You can also attach a wire to it so that you don’t have to get too close to the flower. 
  • Cotton swab. This is also a helpful method, although a bit tedious. You have to use the cotton swab to collect some pollen and move it from male to female parts. You have to be very careful when doing this so as to avoid damaging any parts of the flower. 

While all of these methods are effective, they also take a lot of time to do. So, people have come up with various other methods of pollination within a greenhouse. 

Bees

If you’re not keen on spending too much time in your greenhouse — or if you have a larger building — you can replicate what happens in nature. While most greenhouses don’t have bees, you can always introduce them and thus create the ideal conditions for your plants to thrive. 

It won’t require much work on your part, but you have to be careful not to get stung. Research on companies in your area that provide bumblebees for pollination purposes. There are many that do this, and it can be a lot quicker than some of the other methods. 

Once you rent the bumblebees, the company will install one of their hives in your greenhouse, and the bumblebees will start to pollinate. Remember that it has to be bumblebees or carpenter bees since honey bees don’t produce the vibrations. 

Bees will fly from a flower to a flower, hanging upside down on a flower, and their wings will create this effect where pollen will easily land on the stigma. You should also keep in mind that other conditions have to be met — the right temperature, humidity levels, fertilizers, etc. 

Pollination Spray

Using pollination spray is another alternative to natural pollination. This spray is commonly used in commercial greenhouses, but it’s not the most natural form of creating fresh and healthy produce. 

The spray contains cytokinins which force the ovary to grow. It’s used as soon as the flowers open up, and it’s used frequently. In essence, this is not true pollination as cytokinins will cause the flower to grow into a fruit without pollen landing on the stigma. That’s why you often see huge tomatoes and more of them in commercial conditions. 

So, this is another method that can help you have better yield, but the method isn’t quite what you’d want since no pollination happens. 

Wind

For a more natural method of pollination, you can use the wind. Of course, the conditions have to allow for it, and not all greenhouses can have the wind in them. So, you have to consider all of the factors. 

This is a simple method that involves opening the doors on both sides of your greenhouse and allowing that draft to vibrate around your flowers, causing the pollen to fall onto the stigma.

Play Some Music

Finally, one of the methods that are not as reliable, but still may work is playing some music. As you likely know, music creates vibrations, especially if it’s louder and coming from some of those bigger loudspeakers. 

So, all you would have to do is play your favorite tunes in the greenhouse, and pollination would work. But, keep in mind that this method may not be as reliable as you’d want it to be. You can test it out and see what works best before applying it in your greenhouse. If it works, this method could be a great thing for you since it’s easier than some of the other methods. 

Final Thoughts

Pollinating tomatoes in a greenhouse is certainly not easy, but some of these methods can help you out. While tomatoes are self-pollinating, that extra help from you will create a better yield, and you’ll be happier with the results. 

Keep in mind that the variety of your tomatoes will dictate the conditions you can keep them in and that this affects pollination too. Otherwise, try some of these methods out and see what works best for you. Good luck! 

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