Do Tomato Plants Self Pollinate? (How to Hand Pollinate)


In the past few years, I have noticed that there are not many bees around, but my tomato plants still seem to produce plenty of fruit.  I started to wonder if tomatoes are able to pollinate themselves.

So, are tomato plants self-pollinating?  Yes, tomato plants are self-pollinating.  This means that a single tomato plant can set fruit by itself – it does not need other tomato plants nearby to pollinate and produce fruit.

However, keep in mind that self-pollination does not mean automatic pollination.  There are still factors that can prevent a tomato plant from self-pollinating.  Luckily, there are also remedies for helping tomato plants that are having trouble with pollination.

Let’s start off by explaining what self-pollinating actually means, along with natural methods of pollination.  Then, we’ll get into why you might need to pollinate manually, the barriers that prevent self-pollination, and methods you can use to ensure that you get a good tomato harvest.

What Does Self Pollinating Mean?

A plant is self-pollinating, or self-fruitful, if it can set fruit by itself.  A self-pollinating plant does not need other plants of the same species (or any other species) nearby in order to pollinate and grow fruit.

On a self-pollinating plant, each flower contains both male and female parts.  Tomato plants pollinate by autogamy, meaning the male part (anthers) sends pollen to the female part (stigma) in the same flower.  (Geitonogamy is when the male part from one flower sends pollen to the female part of another flower on the same plant).

tomato flower
Tomato flowers have both male and female parts.

This makes self-pollinating plants, such as tomatoes, ideal for indoor gardening.  You can plant just one, and still get fruit.

However, one drawback is that self-pollinating plants cannot evolve to changes in their environment, since the same genetic material is found in the mother plant and any later generations.

Again, remember that self-pollination does not mean automatic pollination.  There are still certain conditions that need to be met in order for a tomato plant to pollinate itself and produce fruit.  Let’s look at some of the ways that nature helps this process along.

Natural Methods of Pollination for Tomato Plants

There are two main methods by which nature helps plants to pollinate.  One is the wind itself, and the other is living creatures, such as bees and other pollinators.  Both of these can help your tomato plants to set fruit.

Wind

If the wind is strong enough, it can cause the flowers on your tomato plants to vibrate as they move with the breeze.  If this vibration is strong enough, then the male part of the flower (anthers) will release pollen onto the female part of the flower (stigma).  This allows for self-pollination and fruiting.

wind vane
Looks like the wind is really going here!

There is nothing you can do to create wind outdoors to help your plants to pollinate.  However, if you are growing tomatoes in a greenhouse, then make sure to open the door on a windy day.  This will allow the wind to do the work of pollination for you.

greenhouse
Leave the door of the greenhouse open on a windy day.

If you are growing tomatoes indoors, then you can open the windows to let in a breeze on a windy day.  Maybe your tomato plants are not near a window, or the wind has been still for days, or you just don’t want to let the cool air out of your house in the summer.

In that case, you can use a fan to create a breeze to pollinate your tomato plants.  You can also use this trick in a greenhouse if the wind has been still for a while and your flowers are waiting to be pollinated.

Bees and Other Pollinators

Bees are probably the first thing most people think of when they hear the word “pollinate”.   When bees latch onto a flower, the vibration of their wings causes the flower to vibrate.  This vibration has the same effect as the wind: the male part of the flower releases pollen onto the female part.

Unfortunately, the use of pesticides in commercial and residential applications has taken a toll on bee populations in many parts of the country.  If you notice that you don’t have many bees in your yard, there are a few steps you can take to welcome them to your area.

First, you should plant flowers to attract the bees.  Having a few little flowers on your tomato plants is one thing, but plenty of big, beautiful flowers will bring the bees in droves.  While the bees might come to your yard for the larger flowers, they will stop to pollinate the tomato plants as well.

bee on blueberry flower
This bee is busy at work, pollinating your garden.

 Also, avoid using pesticides in your yard or garden.  Even some lawn treatments can kill or repel bees.  You should also ask your neighbors if they will consider going without pesticides.  It won’t help much if you stop using chemicals, but your neighbors all continue to do it.

It will be easier to sell this idea if your neighbors also have tomatoes and other garden plants that need to be pollinated.  If your neighbors are not gardeners, then offer them some of the vegetables you get out of your garden as a gesture of goodwill.

Finally, you can try to get into beekeeping.  It is not for everyone, but it basically guarantees that your plants will be pollinated.  It also means that you can get a nice harvest of honey each year.

One last thought here: if you have row covers over your plants, be sure to pull them back once in a while to give the bees a chance to do their work of pollination!

Why Would You Need to Pollinate a Tomato Plant?

With all this talk of self-pollination and natural methods of pollination, you might be wondering why anyone would need to pollinate a tomato plant by hand.

First of all, pollinating by hand will speed up the process, so that your plants produce fruit that much sooner.  You might not think a few days will make much difference.  However, in a cold climate, a few days can mean the difference between a good harvest and losing lots of vegetables.

Roma tomatoes
You do want more tomatoes, don’t you?

Also, pollinating by hand will increase your tomato yield, so that you can have a bigger harvest.  If you leave things to chance, the wind or the bees may not get to pollinate every flower. This is especially true if the wind is still when your plants flower, or if the bees in your area are dying off.

Finally, there are some other natural barriers to self-pollination, and pollinating by hand is wise when you face these barriers.  Let’s talk about those barriers now.

Barriers to Self-Pollination of Tomato Plants

There are two major barriers to self-pollination of tomato plants: temperature and humidity.  Often, they go hand-in-hand.

If temperatures get too high, pollen becomes unavailable, inhibiting self-pollination.  When daytime temperatures exceed 85 degrees Fahrenheit, or nighttime temperatures exceed 75 degrees Fahrenheit, tomatoes will have trouble with self-pollination.

If humidity levels get too high, the pollen will become sticky, and will not fall from the male part of the plant.  On the other hand, when humidity levels are too low, the pollen may fall from the male part of the flower, but it will not stick to the female part of the flower.

There is not much you can do to control for temperature or humidity in your garden.  If you have a greenhouse, open the door during the day, or even at night, if temperatures will be too high for pollination.

Artificial Methods of Pollination for Tomato Plants

There are several artificial methods you can use to help pollinate your tomato plants.  All of them boil down to the same thing: you are causing the flowers to vibrate, which releases pollen from the male part and sends it to the female part.

Electric Toothbrush

Don’t worry – you don’t have to use your own toothbrush to pollinate your tomato plants!  You don’t even need to buy an expensive one.  Just get the cheapest electric toothbrush you can find – perhaps one that a friend or family member is throwing away.

The idea is pretty simple here.  Turn on the electric toothbrush.  Then, touch it to the back of the flower, to cause the male part to release the pollen.  Sometimes, you will even see a cloud of pollen coming out of the flower.

The vibration of the toothbrush mimics the vibration of a bee’s winds, and acts in much the same way.  The more thorough you are about touching every flower, the better your chances of getting more tomatoes at harvest!

Toothpick, Pencil, or Stick

This method is a little cheaper than the electric toothbrush.  The idea is to take your toothpick (or pencil, or stick) and gently push up (or down) on the flower, moving it slightly out of place.

toothpicks
You only need one toothpick to pollinate your plants.

Then, let the flower go.  When it springs back into place, the movement and vibration will cause the male part to release its pollen.

Tuning Fork

If you are a piano player or musician, you might like this method – and you are more likely to have a tuning fork lying around.  Just tap the fork on a piece of metal or wood to get it vibrating.

tuning fork
A tuning fork – not just for pianos!

Then, use it just like you would use the electric toothbrush.  Touch the fork to the back of each flower while it is vibrating to release the pollen.

Shake the Plant

This method doesn’t require any tools, and it mimics what the wind would do.  All you do is move the tomato plant back and forth to stimulate movement of the flowers.

This method will be difficult to use if the tomato plants are tied to stakes.  It will also cause the stems or branches to break if you are too aggressive with the movement.

Pollination Sprays

This is a misnomer, since pollination sprays do not really cause pollination.  Commonly used in commercial greenhouses, these sprays artificially cause the fruit to start – without actually releasing any pollen.

This is probably not a method you want to use if you are an organic gardener.

For all of the methods mentioned above, just make sure to be careful that you do not damage the plant – flowers, branches, or stems.

Conclusion

By now, you have a sense of what self-pollination is, and how you can help it along, either by natural or artificial means.

I hope that this article was helpful.  If you have any questions, or if any of these methods worked well for you, let me know in the comments below.

jonathon.david.madore

Hi, I'm Jonathon. I’m the gardening guy (not guru!) who is encouraging everyone to spend more time in the garden. I try to help solve common gardening problems so that you can get the best harvest every year!

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