How to Hand Pollinate Tomatoes in Your Garden
Tomatoes are among the most popular and exciting vegetables to grow in your garden, but what should you do when your plants are only producing flowers and no fruits? These juicy red (or orange, yellow, or purple) fruits require pollination from wind and bees, or in some cases, humans. If your tomato plants are dropping flowers or failing to produce fruit, you may need to hand-pollinate them to ensure you grow a harvestable yield.
Tomatoes are among the most popular and exciting vegetables to grow in your garden, but what should you do when your plants only produce flowers and no fruits? These juicy red (or orange, yellow, or purple) fruits require pollination from wind and bees, or in some cases, humans.
If your tomato plants are dropping flowers or failing to produce fruit, you may need to hand-pollinate them to ensure you grow a harvestable yield. Let’s dig into why, when, and how to hand-pollinate tomatoes. It isn’t as tricky as it sounds!
Why Hand-Pollinate Tomatoes?
Hand pollination can improve tomato yields, particularly in an enclosed environment (like a greenhouse or indoor container garden) or during bad weather when natural pollinators aren’t active.
Even when growing outdoors, nature sometimes fails to pollinate our tomatoes. If your plants drop flowers or refuse to develop fruit, a little human assistance can go a long way.
The benefits of hand pollination include:
- Dramatically improve yields
- More tomatoes of higher quality
- Fruits that are true-to-variety
- Better fruit set in a covered environment like a greenhouse or enclosed patio
- Better fruits for indoor and container tomatoes
- Insurance against low-wind days (wind aids tomato pollination)
- Less reliance on pollinators (especially if they aren’t established in your yard)
- Greater buffer against bad weather (most pollinators hide out during bad weather)
Do You Need to Pollinate Your Tomatoes By Hand?
Your tomatoes will probably need pollination assistance if you’re growing in a greenhouse, plastic tunnel, container, or windowsill. Certain conditions call for hand pollination, such as a lack of wind or growing in a protected garden area without airflow.
If there is bad weather, bees may not be active. If it is humid, wet, and muggy, the powdery pollen can clump together and not move, and you may need to pollinate your plants by hand.
Reasons to Pollinate to Hand:
- You are growing tomatoes indoors
- Extra wet or humid conditions are causing clumps of pollen that can’t move
- Extreme dry conditions
- There is a lack of wind or airflow
- Your tomatoes are inaccessible to pollinators (due to row cover or plastic tunnels)
Reasons to Skip Hand Pollination:
- Your plants are sickly (the lack of fruit set is likely due to other causes)
- There isn’t enough sunlight (hand pollination cannot supplement a tomato’s need for 8+ hours of sun)
- Plants are damaged by diseases or pests
- Excessive heat or cold
- Flowers are not developing (there’s nothing to pollinate… you might have over-fertilized with nitrogen)
Are Tomatoes Self-Pollinating?
Tomatoes are naturally self-pollinating monoecious crops. Monoecious means that one plant has both male and female parts.
Self-pollinating means one plant can reproduce on its own. Moreover, tomato flowers are considered “perfect” or “complete” flowers because they have both the female (pistil) and male (stamen) flower parts within each bloom.
In other words, you don’t need two tomato plants to produce a tomato fruit… Well, sometimes. All botanical jargon aside, tomatoes aren’t always perfect at pollinating. There are certain instances where natural pollination isn’t occurring, and they need assistance moving the pollen from the female part to the male part.
Wind and bees are the usual purveyors of tomato sexual favors, but wind usually does the bulk of the work. Air either quivers the plant and knocks the pollen loose or blows little pollen granules from the anthers (male parts) to the sticky stigma (female parts). In other words, the pollen falls within the flower to pollinate itself.
When your garden has abundant floral resources, bees fly in to help. As they try to reach the nectar inside a tomato flower, their furry bodies gather pollen and roll it around, effectively moving the pollen from the anther to the stigma. If your plants continually struggle with pollination, try to attract more pollinators to your garden via native plants.
8 Steps to Pollinate Tomatoes by Hand
Hand pollinating is easier than it sounds. You don’t even need to know the botanical science behind it! Just imagine yourself as a little bee gathering pollen and moving it around. You only need the right timing, a paintbrush or toothbrush, and patience.
Choose the right time
The best time to hand-pollinate tomato flowers is in the middle of the day when a plant has several healthy, open yellow flowers. Ideally, choose a warm, sunny day with low humidity.
Fortunately, this process still works during bad weather conditions. If you live in a crazy humid climate or just received a lot of rain, this method will still work, but you may opt for the electric toothbrush to help distribute the clumpy pollen more easily.
If you want to skip all the steps below, simply shake your plants. A firm shake from the top of the plant will cause the flowers to release pollen and distribute it to the female flower parts. Commercial pollinators use electric vibrator devices to achieve this on a larger scale.
As a bonus, shaking can help you find tomato hornworms. If you rattle your tomato trellis around, hornworms will often hiss at you (those little demons!), revealing their camouflaged spot on the tomato foliage.
You could also add a strong fan to the area to simulate blowing wind.
Use a small brush
You can use a tiny paintbrush or a toothbrush to hand-pollinate your tomatoes. Some people even use an electric toothbrush to ramp up pollen distribution! A Q-tip, or worst-case scenario, your finger can also work.
Move the brush around inside the flower
Because tomatoes have perfect flowers, you don’t have to move pollen from one flower to another as you would with squash. Instead, move your tool around inside each flower, shake it well, and move to the next.
Transporting pollen between flowers is no big deal if you grow the same variety. However, you could have a few funky “off-types” if you cross-pollinate two different cultivars and then try to save seed from the resulting fruit. Cross-pollination does not impact the type of fruit your parent plant produces, only the seeds it generates.
If you’re using a paintbrush, gently insert it into an open flower and move the tip of the brush around. You can also hold the base of the flower and shake the bloom, taking care not to remove it from the stem. Some people blow into the blossom as they move the paintbrush.
Electric Toothbrush Method
If you’re using an electric toothbrush, turn the toothbrush on and gently place the back of the toothbrush on the back of the flower. Putting the actual bristles of the brush onto the flower is unnecessary. Avoid inserting the toothbrush into the blossom or you might damage the flower.
If you prefer the Q-tip method, first use a bag or bowl to collect pollen. Hold the container under a cluster of flowers and gently shake the plant until you see yellow pollen falling out. Next, dip your Q-tip into the powder and transfer it to each flower. Roll the Q-tip around to thoroughly coat the floral parts. You can even use your finger!
Be very gentle
Tomato blossoms are fragile and can easily rip or fall from the plant. No matter what method you use, be careful not to damage the flowers. If you’re afraid of touching the flowers, shaking the plant is the ideal method for you.
It’s best to hand pollinate with your bare hands so gloves don’t impede your nimble fingers. If you accidentally knock a few flowers off, no big deal! Most tomato plants will grow back more in a few days.
Repeat every 2-3 days
To ensure optimum yields, it helps to shake, vibrate, or transfer tomato pollen every few days while conditions are ideal. This isn’t 100% necessary, but it gives you the maximum chance at success.
In my garden, I prioritize the tomatoes that need it most: those growing in the high tunnel and those that produce the largest heirloom fruits.
Check that tomatoes are pollinated
Observing the stem is the easiest way to tell if a tomato flower is pollinated. Every flower emerges from the central stem on a smaller green stem.
If the stem stays green and enlarges into a little green bulb at the base, the flower is successfully pollinated, and the fruit is growing. The bulbous growth is an ovary where the fruit will grow.
Pollination has failed if the flower’s stem turns yellow and begins to wither. You won’t see any enlarging ovary at its base.
In both cases, the flower will eventually drop from the plant, so don’t panic if you see tomato flowers on the soil. A pollinated flower will wilt within 24 hours and fall off the plant in a couple of days.
Depending on whether you have a determinate or indeterminate plant, your tomato may only produce flowers during a two-week period (determinate) or continue producing flowers for the duration of the season (indeterminate).
Support plant health
Once you’ve completed your tomato pollination mission, check that your plants receive everything they need. They should be robust and vibrant green with strong stalks and plenty of leaves. They should actively produce new flowers every week and send out suckers (which you may want to remove for optimal yield).
When a tomato plant begins flowering and fruiting, avoid feeding it any additional nitrogen. Too much nitrogen can promote excessive foliage growth.
We want the plant to channel its energy into fruits! Ideally, you should fertilize when planting with an all-purpose blend like Espoma Tomato-Tone.
After hand pollination, it’s a great time to add another dose of Tomato-tone or any fertilizer high in phosphorus. Phosphorus (the middle number on N-P-K) is most important for producing large, juicy, delicious fruits.
Most tomato varieties yield mature fruit two to three weeks after the flowers open. However, it should be clear whether pollination was successful within a week.
Once the fruit begins growing, all you need to do is be patient! Let your tomatoes ripen on the vine for the best flavor.
When nature can’t quite pollinate on her own, you can easily step in to boost your tomato yields. Your method doesn’t matter if the blossoms vibrate and shake to distribute pollen from the male to the female flower parts or if you manually apply pollen. Remember, be gentle and look for the enlarged floral stem base to indicate success!