This spring, my partner and I planted a small orchard on our new property. We ran into some confusion when deciding how far apart to plant our chestnut trees. Turns out there isn’t a simple answer, because of pollination!
What Is Pollination And Why Is It Important?
Briefly, pollination is how plants sexually reproduce, how they exchange DNA. Flowers are the reproductive organs of plants. Like animals, plants have ovaries and produce eggs, which need to be fertilized by pollen to create a new seed.
All fruiting plants, including fruit and nut trees, berries, tomatoes, and others, need pollination. Even more importantly, all plants need to be pollinated—by insects, by wind or by hand—in order to produce viable seeds that can be planted next year. Without pollination, not only would human crops stop producing food, but wild plants that feed all the other animals in the world would also stop growing.
The problem with our chestnut trees was that they needed to be growing close enough to each other to cross-pollinate, or the tree won’t produce nuts. But chestnut trees grow so large that trees planted too close together eventually shade each other and produce fewer nuts. This isn’t such a big deal in a small, household orchard. But if you’re a nut farmer, fewer nuts could put you in the red.
Pollination is valuable to everyone, not just farmers. Pollinators contribute tens of billions of dollars yearly to the global economy.
This video by “We The Economy,” called A Bee’s Invoice, uses the value of bees to explain the value of all natural systems on Earth.
If pollinators disappeared, the total financial loss to agriculture and the world economy would be staggering. Many plants can be pollinated artificially by hand, but the labor costs involved would be massive. This potential doomsday scenario spurred Harvard scientists to develop robot bees. Clearly, the best option is to protect and support the pollinators we already have!
Honeybees And Commercial Pollination
The European Honeybee, Appis Mellifera, is the commercial staple, both for their pollinating and for making honey.
Honey is a miraculous natural sweetener, and the profession of beekeeping is an ancient, revered, even mystical practice. People harvested honey as least as far back as 17 millennia ago. Honey has been used both as food and medicine and is mentioned in religious texts around the world.
While many other aspects of ancient life have changed and vanished, beekeeping is still a vital part of food and agriculture today.
Large commercial operations truck hives of A. Mellifera from farm to farm to provide pollination services. In 2015, a bee truck rolled over on the Interstate near Seattle, spilling almost $100,000 worth of bees. As ridiculous as that sounds, similar traffic disasters have occurred in Idaho and North Carolina.
Traffic accidents are not the biggest problem with trucking bees, however. Bees that travel a lot are more stressed and more susceptible to disease. Since they are generally going between large monocrops, they get less nutritional variety. This interrupts their natural patterns of foraging.
A. Mellifera is not the only bee in the game. Commercial and human-managed hives can only pollinate a small fraction of all the crops that rely on insects. Native bees act as vital pollinators for native plants and commercial crops. Not all of them produce honey, though, which is why they have not achieved fame in human cultivation systems. North America alone hosts four thousand species of native bee.
Bees are not the only important pollinators. Other bugs, like wasps, flies, beetles,and butterflies—even bats and birds—pollinate the world’s plants. One study found that although bees are the most effective pollinators when they visit a flower, other pollinators visit flowers more often than bees. Bees and non-bees are equally important to global ecosystems.
Threats To Pollinators
Over the last decade, the welfare of pollinators has become a matter of worldwide concern. Bees and other wild pollinators like wasps, flies, birds and bats, are dying. Colony collapse disorder (CCD) gets lots of attention, but it’s only one of a multitude of coinciding factors threatening honeybees.
All bees, native and domestic, are adapted to live in diverse habitats, with nutritionally and microbially complex diet. In the wild, bee colonies either die over winter, or survive on their stores of honey. However, since commercial operations harvest honey, their bees are fed supplements of sugar water. Scientists still struggle to create a synthetic substitute that will truly support bee health.
Native pollinators are being threatened too—mostly by disruption of natural habitat. Like all other wild critters, pollinators are threatened by urban sprawl, agriculture, and forestry. Populations of native pollinators need a consistent variety of flowering plants. Acres of soy, all blooming at once, cannot support a population of local pollinators.
What Can You Do To Support Pollinators?
To prevent bee death, the USDA’s Agricultural Research Service recommends reducing the use of pesticides in home gardens and lawns. Pesticides are a major threat to bees. Neonics, the most common class of insecticide, has been confirmed to kill bees (obviously, since bees are an insect). If a bee isn’t killed by pesticide exposure, they’ll still suffer from a weakened immune system. Even non-lethal exposure to pesticides endangers bee populations. If you are having pest problems, try vinegar traps, or introducing other predatory insects.
To support bee nutrition, gardeners and farmers can plant insectaries, a mix of plants that bloom through the whole growing season. These diverse combinations of flowering plants will not only support pollinators but will also boost your garden’s productivity. Since your raspberries need to be pollinated in May but your tomatoes in July, you need pollinators all year round.
Some seed companies sell mixes of flower seeds chosen to support local native pollinators. Portland seed company Hobbs and Hopkins warns against seed fraud. They allege that many wildflower mixes are overpriced mixes of domestic flower seed, or worse, mostly fillers like vermiculite. If you do decide to buy a mix, look for one that lists all the seeds contained. The most effective and least expensive option? Research local pollinator-friendly plants and buy those individually.
Bee-friendly Flowers And Flowering Plants
What to Plant
Crocus, lavender, borage, heather, flowering currant, apple, muscari, flowering quince.
Foxgloves, bee balm, cosmos, sunflowers, mint, poppy.
Zinnias, basil, asters, alyssum, sedum, snowbanks.
Native bees don’t all build hives. They may depend on you to build a home for them. Leave small brush piles and dead leaves in some corner of your yard to provide habitat for wood and brush nesting bees. Ground bees like to nest in well-drained soil, like on a hillside.
Most of these native bees are not aggressive. Once, I was sitting on a slope at a local park, and noticed a number of bees circling lazily in the area. I didn’t think much of it, and sat talking to a friend for probably an hour. When we got up, I noticed that the bees, four or five of them, immediately flew down and crawled into a hole in the ground, directly under where I had been sitting. I had sat on a ground bee hive for an hour and not been stung!
To many gardeners, pollination is an invisible contribution from our local ecosystem to our local food system. When we see a bee land on a flower, it is easy to forget the enormous scale on which pollination takes place. The more we study pollinators, the more vital and fragile our co-existence seems. Bees are so fascinating that the greatest mind in 20th-century fiction, Sherlock Holmes, retired as a beekeeper in Arthur Conan Doyle’s His Last Bow. While we can’t all become beekeepers, we can all do our part to understand and support our small, vital friends.