Ready to talk about the birds and the bees? No, literally! There are very few things in this world that match the significance of pollination and the role it plays in your life, whether you’re aware of it or not. Pollination occurs so seamlessly in nature that it's easy to miss, but to ignore it completely when trying to grow your own fruit would be a shame.
To put into perspective how important the process of pollination is, imagine a world where no more babies were born. In plant terms, if you stop pollination, you essentially stop the creation of new life.
Simply put, pollination is the process of sexual reproduction by which a seed or fruit is made. No pollination means no fruit, no flowers and no life. The world as we know it exists thanks to pollination, and it's well worth your time to make sure you get it right when growing your own fruit. However, pollination can be complicated and difficult to understand when you don't know the basics of the process. Keep reading to learn and master all things fruit tree pollination!
How the Pollination Process Works
Pollination is the process by which pollen is transferred from one flower to another, resulting in a fruit or seed being made. Of course, there’s more to this process than just a pollen grain transfer, so let's start with the parts that need to be present for everything to happen.
Just like other living things that sexually reproduce, there are male and female parts and parts that are universal that help this whole process occur.
The female parts of the flower are collectively called the “pistil”. The pistil is comprised of the stigma, style and ovary that work together to transfer the pollen from the top of the stigma, down the style to the ovary, which has the ovule (aka. the egg) that gets fertilized.
The ovary, once fertilized, swells and grows into your fruit with a thick barrier around it to project the precious seed inside. Think of an apple with seeds at the core.
The male parts of the flower are collectively called the “stamen”. The stamen is comprised of filaments, anthers and pollen grains. The filaments hold up the anther, which is where the pollen grains are made and released to the world in hopes of finding the female counterpart.
Since pollen has to go on a journey, there’s a LOT of pollen produced (hence, why your car turns yellow in spring) and it's built to be indestructible, so much so that there are millions of fossilized pollen grains that have survived the test of time.
Other, but equally important parts of the flower that help pollination along are the petals and bracts. The botanical term for petals is “corolla” and is what you’re most likely already familiar with. Bracts are modified leaves that surround the flower. In some flowers, the actual petals are so small that the bracts are colored and attract the pollinators instead.
Some examples of showy bracts acting as flowers can be found on the poinsettia, hydrangea, and bougainvillea plants, which is why they last so long. The “petals” are actually colorful leaves. The design, shape and color of the petals and bracts are specific and intentional to the pollinator it wants to attract, but we’ll touch more on that later.
Pollination in a Nutshell
Here’s how the general process works for all flowers:
- Flower opens, releases pollen from the male anther and attracts pollinators with its colors, shape and smell
- The desired pollinator visits the flower and gathers pollen
- The pollen is spread by the pollinator visiting different flowers and different trees.
- When the pollen grain connects with the female stigma, the flower is fertilized
- The petals will fall off the flower and the fruit will start to grow.
Nature has the process of pollination down to a science, from dropping its petals when a pollinator is no longer needed, to creating enough reward for pollinators to visit their flowers. There are thousands of variations of this process that exist, but you just need to know that all parts of the flower must be present for it to occur and that the pollen must genetically match the flower it pollinates with to produce fruit.
Helpful Pollinator Terms to Know
Since pollination can be complex, here are some popular terms you might see and what they mean:
Self pollination occurs when the pollen from one flower can fertilize itself, either the exact same flower or another flower located on the same tree.
Cross pollination is when pollen from a separate flower fertilizes a flower on a completely different tree. For some fruits you have to have this to happen to get the fruit.
Translates to “two-houses” and is the category of plants that have separate male and female cultivars of plants.
Translates to “one-house” and is the category of plants that have male and female flowers on the same tree
Not all Flowers and Trees are Built the Same
Of course, when it comes to something so diverse as plants you can’t expect them to all operate the same way. There are some plants that are only female, others that are both and some that even change! To help navigate which is which, here are the categories of plants and which kinds of fruits belong to them.
Kinds of Flowers
There are three main types of flowers that exist:
- Male-only flowers with male-only reproductive parts
- Female-only flowers with female-only reproductive parts
- A “perfect” flower that contains both male and female parts
Kinds of Trees Based on the Flowers They Have
To make things even more complicated, these three types of flowers can be arranged differently depending on the tree. This might be mind blowing if you just learned that plants are male and female, so look at the chart below to see which fruits fall into which category to take the guesswork out of it!
Example Fruit Trees
Perfect flowers only (flowers that have both male and female parts)
Female flowers and male flowers are separate but on the same tree
Female flowers only on one tree
Male flowers only on one tree
Most of your fruit trees will have perfect flowers on one tree, so that you have male and female parts in every flower. However, there are occasionally some like kiwis where you will need both male and female kiwi plants to see any fruit. Fruits that have separate male and female flowers on the same trees, like avocados and pomegranates, do well with hand pollination to make sure pollen gets around equally.
As you can see, pollination can be quite complex, but when you break it down you really just need male parts, female parts and compatible pollen. Just because your tree has male and female flowers on the same tree or perfect flowers doesn’t mean you’ll get fruit with one tree - some trees need to be cross pollinated.
You can always check if you need a pollinator by looking at the “pollination tab” of a variety on our website or by visiting your local extension website to find more detailed information about the pollination requirements for your trees. Most fruits will have male and female flowers on the same one, but in the case like a kiwi, just make sure you have room for two!
Meet the Pollinators
No pollinators means no fruit, so next time you see any of the pollinators listed below, make sure to say thank you!
Insects are the most well-known and common pollinators and carry out the process of fertilizing plants. Some common insects that you might recognize include bees, wasps, bumblebees, butterflies, moths, ants, flies, and beetles.
Insects are not the only pollinators out there. Some plants rely on animals like birds for fertilization. Common pollinators in this category are hummingbirds, bats and songbirds.
The wind can be a mighty thing, and some trees use it to their advantage to get pollinated. A good example is a walnut or chestnut tree that has long, tassel-like flowers that sway in the wind and disperse pollen in the air. This is often the reason for seasonal allergies too!
Water is used by the plant to grow but also reproduce. Plants that grow near or in water may use it as a mode of transportation to spread and travel from flower to flower.
How Flowers Match the Pollinator
Not all flowers are attractive or even smell nice. Flowers exist for function, not beauty. By knowing what kind of flowers you have in your garden, you can match them to their pollinators! Check out our list of pollinators below and the plants they’re attracted to.
- Moths: Big white flowers that open during the night will draw in moths. The white reflects the moonlight, attracting the moths and it opens at nighttime when moths are most active.
- Flies: Dark brown and red flowers that smell like rotting meat will attract flies. Fruits like the pawpaw and even the cocoa depend on them.
- Hummingbirds: These birds typically flock to orange or red flowers that have a trumpet shape for their beaks to fit into.
- Bees: Large, showy flowers with bright colors and sweet scents attract bees. Most fruit trees will be pollinated by them.
- Beatles: These are very primitive pollinators before bees and butterflies were around. They’re not the most graceful, so most flowers that are beetle-pollinated will be cupped or bowl-shaped with shallow pollen. Think of a magnolia flower.
- Wind: Long, tassel-shaped flowers called catkins hang down and sway in the wind, dispersing their pollen to the sometimes sticky female flower close by. This is a popular style you’ll see with nut trees.
- Butterflies: These flying friends aren’t as efficient as bees due to the shape of their bodies. However, they can maneuver much better than your average bumblebee, making slender, tube-like flowers that hang at different angles perfect for them.
Tips on How to be Pollinator-Friendly
1. Don't Blindly Spray
There are many chemicals and sprays you can use to control pests like mosquitoes and wasps, but did you know that the same sprays might be killing off your bees, as well? To avoid this, read the label! Make sure you know what you’re putting in your environment to avoid unintentionally killing off pollinators. Also, only spray if you absolutely must - many times you can combat pests using natural alternatives (i.e. citronella repelling mosquitoes).
2. Support Their Life Cycle
Insects like butterflies feed on milkweeds, lay eggs under the leaves, then have to survive being a caterpillar long enough to transform into a butterfly. If you want butterflies to stay close by, do more than just plant milkweed - keep an eye out in your garden for hidden eggs or caterpillars and avoid cutting your garden back hard or too soon to provide them a safe space.
3. Let Mother Nature Take its Course
Nature is oftentimes messy and fallen leaves, grass clippings or plants that die back may mess up your perfect lines, but learn to embrace the mess! One of the best things you can do for your backyard pollinators is letting nature take the lead. Consider dedicating part of your landscape to nature - don't rake up all the leaves and debri and let the wildflowers grow and naturally die back. Sure you might lose some of the manicured look in that area, but your pollinators will thrive!
Next time you’re in your garden and see a pollinator buzz by, make sure to thank them for their service! Without all of these hardworking friends, we wouldn’t be able to live life as we know it and your fruit trees wouldn’t exist. Make your yard a hospitable place for pollinators, and you’ll be well on your way to hefty harvests of your favorite fruits!
To keep learning, check out the rest of our Fruit Trees 101 Course, filled with all the sweet tips you need to create your backyard orchard!