The Raintree Nursery Guide to Pollination
Some of the most common questions we get here at Raintree Nursery are about pollination. Honestly, those are pretty good questions and deserve a closer look to explain more completely.
Pollination itself is the "act of transferring pollen grains from the male anther of a flower to the female stigma". Because the goal of every plant is to create offspring for the next generation there are a lot of ways plants do that, but the ones you want to know about result in making fruit!
First, let's make one thing clear: pollination and propagation are completely different things. In this email we are focusing on pollination exclusively because it's the fruit-related subject. Now that we've got that straight, let's take a few minutes and cover the most common pollination strategies plants use - insect pollination and wind pollination.
Insect pollination is easily one of the most common strategies that plants use. The kind of pollen these kinds of plants produce is specialized to attract, feed, support, and ultimately rely on insects to move their pollen around and create fruit. Typically insect-pollinated plants have evolved bright colors and different shapes of flowers to attract certain favorite kinds of insects to do their pollination work. The pollen grains produced by these plants are sweet and nutritionally dense food for their insect partners.
Wind pollination is more or less the exact opposite. Wind pollinated plants rely on wind to disperse their pollen to waiting pollination partners in a way much more passive than insects would spread it. As a result the flowers are smaller, less colorful, and may even have no petals! These flowers produce huge amounts of pollen that travel on gusts of wind and are caught by female flowers along the way. Wind pollinated plants aren't usually very good for pollinators like bees because their pollen doesn't contain much nutrition.
Self Fertility vs. Cross Pollination
This is the point most people get confused at and for good reason. While nearly all fruit plants require some form of pollination, depending on the variety and species of the fruit you are trying to grow, the pollen may or may not need to come from a different variety of the same kind of fruit.
Trees that can set fruit using pollen from their own male flowers to pollinate their own female flowers are called self-fertile, or self-fruitful. Self-fertile varieties are highly prized by backyard growers that don't have unlimited space for multiple different varieties of same fruit type. Very few self-fertile trees are what is considered completely self-fruitful however, as not every female flower is able to accept pollen from it's neighboring counterpart. Because of this, the fruit set can be dramatically higher if you plant a compatible tree nearby for cross-pollination.
To dig just a little deeper, it should be mentioned that some plants will set fruit without pollination at all. Occasionally you will run across fruiting plants, like some figs, that are able to set fruit without any pollination at all, a phenomenon known as parthenocarpy. That's great because it means you can enjoy them even in areas where pollination is limited or impossible - like inside your house!
Common Insect Pollinators
Alright, now that you've got all your plants and their pollination needs mapped out, we need to make sure the right pollinators are available to help! Most fruit trees are pollinated by honeybees, but honeybees are far from the only pollinator insects involved in a successful orchard. Let's take a brief look at the different kinds of fruit tree pollinators that are out there and what conditions you can create to promote their health and activity!
Honeybees are favored by commercial orchards as fruit tree pollinators due to their aggressive pollen gathering behavior and numerous population. Typically honeybees live in dedicated hives with a communal work and living model that's directed by a queen bee hidden deep in the hive, away from danger. Honeybees take a fair amount of care and management, if you want the honey they produce (as most people do), but they can also be kept in less specialized boxes and allowed to sustain themselves.
Mason Bees, unlike honeybees, are solitary bees that play no less of an important role in the success of a fruit orchard. Mason bees are native to the United States (which honeybees are not) and live in solitary nests that they build into tubes or crevices with mud. Mason bees are smaller than honeybees, but very productive and many home growers build habitats for their local mason bee populations to enjoy the fruits of their labor every year.
Bumblebees are non-aggressive ground dwelling bees that get their name from their wobbly flight pattern and flower-jiggling size. Bumblebees are larger and slower than honeybees, but they make up for it with a special form of "buzz pollination" that literally vibrates the pollen out of the flowers. Bumblebees can often been seen laden with huge amounts of pollen before they return to their semi-social ground hives. Bumblebees hives are commonly found under pots and planters, making them a great growing partner for outdoor container gardens.
Flies are a lesser known, but still critical pollinating insect in nearly every climate where fruit is grown. Flies are compatible with almost all kinds of fruiting tree and bush, sometimes even assisting with wind pollinated plants. Some fruiting plants, most famously paw paw trees, are specialized for fly pollination, producing a rot-like scent that attracts flies better than the sweeter-smelling pollen of common fruit trees.
We are here to help
Successfully growing plants is a journey and here at Raintree Nursery we want to do whatever we can to help you meet your goals. Checking out our Growing Guides for pollination charts and flowering times is a great place to start, but if you need help you should always feel free to e-mail or call us at the nursery with any questions you might have about any of the dozens of factors that go into successful fruit growing in your home orchard.