Tomatoes are usually self-pollinating, with each flower containing male and female parts. However, in certain situations – such as when growing indoors, in a greenhouse, or when the usual pollinators are scarce – gardeners may need to step in and assist with the process.
If you find yourself in such a situation, don’t worry. This guide will walk you through the process of hand-pollinating your tomato plants.
Understanding Tomato Flower Anatomy
Before you start, it’s useful to understand the anatomy of a tomato flower. The critical parts are the male part, the stamen, which carries the pollen, and the female part, the pistil, which receives the pollen.
A cone of fused stamens surrounds the pistil in tomato flowers, making self-pollination quite likely. However, pollination can sometimes be inhibited, particularly in the absence of wind or insects to disturb the flowers and dislodge the pollen.
Why You Should Hand Pollinate Your Tomato Plants
Hand pollination may seem like an extra, unnecessary step in the tomato growing process, especially considering that tomato plants are generally self-fertilizing. However, there are several reasons why hand pollination can be beneficial and sometimes even necessary.
1. Improve Pollination Rates
Although tomato plants can self-pollinate, the process isn’t always effective. If environmental conditions are not ideal, the natural process of pollination can be less efficient. By hand pollinating, you’re giving nature a helping hand and increasing the chances of each flower turning into a fruitful tomato.
2. Maximise Yields
Hand pollination can lead to higher yields. By ensuring that each and every flower has the best chance of being pollinated, you’re essentially increasing your tomato production capacity. This can be quite advantageous for those who are growing tomatoes for sale or aiming for a large harvest.
3. Encourage Fruit Set in Challenging Conditions
Tomato plants sometimes have trouble setting fruit in challenging conditions such as very high or low temperatures. In these situations, hand pollination can boost the plants and increase the likelihood of a successful fruit set.
4. Necessary for Indoor or Greenhouse Growing
If you’re growing tomatoes indoors or in a greenhouse, pollinators like bees and butterflies might not have access to the flowers. In these cases, hand pollination is not just beneficial – it’s necessary.
5. Breeding and Preserving Heirloom Varieties
Hand pollination is a must for those interested in breeding their own tomato varieties or preserving the genetic purity of heirloom varieties. This technique controls the pollination process, ensuring that the resulting seeds carry the desired traits.
When to Hand Pollinate
The best time to hand pollinate tomato flowers is mid-morning, as this is when the flowers naturally open, and the pollen is loose and easily transferred.
It’s also best to wait until the flower has fully opened. If the yellow petals have folded back away from the centre, this is usually a sign that the flower is ready for pollination.
The Process of Hand-Pollinating Tomato Plants
Now, let’s delve into the step-by-step process of hand pollination:
- Identify the Open Flowers: Start by identifying the flowers that are ready for pollination – those that are fully open, with petals folded back.
- Select Your Pollination Tool: Many gardeners find that a small, soft paintbrush or a cotton swab is the perfect tool for hand pollination. It can pick up the pollen and deliver it without damaging the flower.
- Collect the Pollen: Gently insert the brush or swab into the flower, touching the stamens to collect the yellow pollen. You should see yellow pollen grains sticking to your chosen tool.
- Transfer the Pollen: Lightly touch the pistil’s end with the pollen-coated brush or swab. This mimics the action of a bee’s body brushing against the pistil, depositing the pollen.
- Repeat the Process: Continue this process, moving from flower to flower. You can collect pollen from multiple flowers and cross-pollinate, which can help increase the genetic diversity of your plants.
- Monitor Your Plants: Monitor the pollinated flowers over the next few days. If pollination has been successful, the flower will begin to wilt and a small fruit will start to develop at the base.
Alternative Hand Pollination Techniques
Some gardeners use an electric toothbrush for hand pollination. The vibrations from the toothbrush simulate the vibrations that a buzzing bee would create, helping to dislodge the pollen.
To use this method, hold the back of the toothbrush against the flower’s stem (not the flower itself). The vibrations should help shake the pollen loose.
While hand pollinating is rarely necessary when growing tomatoes outdoors, it can be an invaluable technique for indoor gardeners or those in low-pollinator areas. It’s a simple but delicate task that can significantly impact your tomato yield. So, next time your tomato flowers look like they could use a little helping hand, why not give it a try?
Tomato Plant Hand Pollination FAQS
When should you hand pollinate tomatoes?
The best time to hand pollinate tomatoes is mid-morning when the flowers are fully open and the pollen is easily transferable.
Do you need to hand pollinate tomatoes in a greenhouse?
While tomatoes can self-pollinate, greenhouses often lack the natural pollinators like bees or the wind required to facilitate this process. In these situations, hand pollination can help ensure your plants bear fruit.
How do you know if a tomato flower is pollinated?
If a tomato flower has been successfully pollinated, the petals will begin to wilt and fall off after a few days. Following this, you should see a small green tomato starting to form at the base of the flower.
Do tomatoes need to be pollinated indoors?
Yes, indoor tomato plants need to be pollinated, and in the absence of natural pollinators, hand pollination is usually necessary.
Why do my tomato plants have flowers but no tomatoes?
This could be due to a lack of pollination, or it could be due to environmental stressors like temperature extremes, insufficient light, or improper watering.
Do you need two tomato plants to cross pollinate?
No, tomato plants are self-fertile and do not need another plant to produce fruit. However, if you want to produce hybrid varieties, you will need at least two different varieties to cross-pollinate.
What happens if tomatoes don’t get pollinated?
If a tomato flower doesn’t get pollinated, it will not produce fruit. The flower will eventually drop off the plant.
How can you tell if a tomato flower is male or female?
Tomato flowers are actually hermaphrodites, which means they have both male and female parts. The male part is the stamen that holds the pollen, while the female part is the pistil which receives the pollen.
How often should you self pollinate tomatoes?
During the flowering stage, you should aim to hand pollinate your tomatoes every two to three days. This frequency gives new flowers a chance to open and older ones a chance to set fruit after being pollinated.
Brian Sheridan has an allotment in Edgbaston and is a competitive grower. Brian is also a keen photographer and loves cooking. Brian and his wife Mary will also be running a stall at Edgebaston artisan market this year, selling products made from the allotment, including his award-winning relish!