pollination

Ways pollination saturation can help crops but exploit our bees

Pollination saturation: how many hives per acre?

Sometimes growers double or triple the usual number of honey bee colonies in a field or orchard in order to get sufficient pollination. For the bees themselves, it means more competition for scarce resources.

Inside: Pollination saturation is a little-known technique for increasing the pollination rate of certain crops. It works well, but some people believe it’s unfair to the bees.

Flooding a crop with bees

Pollination saturation (sometimes called saturation pollination) is the practice of flooding a crop with an overly-large number of honey bee colonies in order to assure adequate pollination

Growers use pollination saturation when the crop to be pollinated, such as alfalfa or cranberries, is not a honey bee favorite. Or they may use it when luscious nearby weeds are blooming concurrently with the crop. If honey bees crave the nearby weeds more than the crop, they’re gone until their preferred nectar disappears.

For example, blueberries are not a favored plant, although honey bees will forage on them if nothing else is available. But if the farmer next door is growing cabbage seed, the honey bees will abandon the blueberries in favor of the sweet nectar of cabbage. In that case, to assure adequate blueberry pollination, the blueberry farmer must bring in extra colonies of honey bees.

Extra bees cause lots of competition

Adding extra colonies, double or triple the normal number, brings an outrageous number of bees to a small area. So many, in fact, that the preferred nectar soon disappears. When that happens, bees have no choice but to work the crop they don’t like…or waste time and energy flying further afield.

With so many bees in one spot, they vie for any nectar and pollen they can find. Honey bees fiercely compete with each other and with native bees, butterflies, and others. Introducing so many colonies puts food stress on all the local pollinators.

While many people are quick to blame honey bees for competition, a lot depends on the growers and the beekeepers. The bees themselves can’t be blamed for a situation humans put them in.

The practice began in California alfalfa but is now common

Pollination saturation first became a thing back in 1948, and it works for specific crops such as cranberries, blueberries, alfalfa, ladino clover, alsike clover, kiwifruit, and some melons and squashes.1 Traditionally, most crops require 2-3 hives per acre for good pollination, although the actual number varies from 1 to 7, depending on the crop. But in recent years, that number has risen because of the loss of wild bees and the decimation of feral honey bee colonies.

Losses of wild bees are likely because of pesticides, monoculture crops, habitat destruction, and climate change. Feral honey bees have all those issues along with varroa mites, viruses, and other pests and pathogens.

Pollination saturation is simply another tool that can be both useful and detrimental. It’s one of those things that beekeepers should know about, even if they never use it themselves. 

Rusty
Honey Bee Suite 

  1. Saturation pollination. (2018, July 18). In Wikipedia. https://en.wikipedia.org/wiki/Saturation_pollination

About Me

I backed my love of bee science with a bachelor’s degree in Agronomic Crops and a master’s in Environmental Studies. I write extensively about bees, including a current column in American Bee Journal and past columns in Two Million Blossoms and Bee Craft. I’ve endured multiple courses in melittology and made extensive identifications of North American bees for iNaturalist and other organizations. My master beekeeper certificate issued from U Montana. I’m also an English nerd. More here.

1 Comment

Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.