Your Pollination Primer (just in time for spring blossom season!)

Author: 
Paige (NSO Greenhouse Manager)
Published: 
Thursday, April 19, 2018

As farmers and consumers, why do we need to worry about pollination at all? Easy answer: because one third of the crops we eat rely on it! Any fruiting bodies that we eat, with a few exceptions, rely on pollination and proper fertilization to be recognized as edible. Apples, peaches, plums, zucchini, walnuts, melons, tomatoes, peppers, almonds, and pears all begin as blossoms, and if those flowers aren’t pollinated correctly, it might form a tiny, shriveled, or improperly developed fruit, which no one would want to eat.

Pollination happens when pollen grains from the anther of a flower travel to the stigma of a flower of the same species, causing fertilization. This allows plants to create seeds, in the process passing on genetic information from one generation of oak trees or broccoli plants to the next.

Some plants utilize perfect flowers, in which the stamen (pollen-producing part) and pistil (pollen-receiving part) are contained in one flower. In other species, the stamen and pistil are housed in separate flowers, and only the pistil-containing flower will bear fruit. Some types of plants are self-pollinating, in which a single plant can pollinate itself, while others can only reproduce through cross-pollination. Most plants need assistance in transporting pollen from flower to flower. They elicit the help of vectors such as the wind, animals, and insects like bees, wasps, butterflies, beetles, and flies. Plants can attract birds, bats, and insects to their blooms with the help of fragrance, coloration, and mimicry. Many insects consume pollen and nectar; they collect pollen on their bodies as they do so, and spread it to other flowers. Plants and insects can even evolve alongside one another to reach a symbiotic relationship, such as in the case of the yucca plant and yucca moths, which rely on each other for survival.

Many farmers keep honeybees or plant extra flowers to promote insect pollination of crops. But sometimes, farmers have to intervene, especially if plants are kept under cover and away from insects. For instance, tomatoes are self-pollinated (although bees can help!), but we need to ensure that plants are kept in a certain temperature range, and also jostled or blown by the wind so that pollen can drift easily from one part of the flower to the other. Other vegetables, like squash, won’t do so well if insects can’t get inside to pollinate them. A farmer can use a small wand or denuded stamen to spread pollen from flower to flower (yep, the farmer can pretend to be a bee...although not nearly as efficiently!). Some seed companies have acknowledged this hurdle, and selected certain fruits and vegetables to be parthenocarpic: a naturally-occurring phenomenon in which a plant doesn’t need to be fertilized to produce fruit (think of your seedless watermelon and hothouse cucumbers).

At NSO, we sometimes control the pollination of flowers on purpose, with the goal of breeding new apple and vegetable varieties for flavor and hardiness. Be on the lookout for our own varieties at market, such as Ludicrisp and Monolith apples, and those amazing rainbow beets and Purple Zebra eggplant!

(Editor's Note: A common question we receive from folks is "Do you keep bees on the farm?" While we have in the past kept hives of honeybees, most years over the last 10 we have not. However, we see LOTS of pollinators flying around every spring! From honeybees who live elsewhere (they'll travel for miles for luscious nectar) to wild pollinators of every kind, the orchard here at NSO is literally abuzz with activity during blooming season!)

Check out the links below for more information on pollination and to learn how you can help bolster failing pollinator populations in the U.S.

Who knows...some of this information may be helpful on your next trivia game night!

USDA: "What is Pollination?"

US Fish and Wildlife Service: "Pollinators"

Natural Resources Conservation Service: "Insects and Pollinators"

Pollinator.org