Let’s Talk About The Birds and the Bees

The summer heat has arrived in Appalachia, and when the heat is turned up in our gardens, our fruiting plants are putting their energy into reproduction. When fruiting plants undergo fertilization, female flowers develop fruit. Naturally, this process has evolved in order to encourage extensive seed dispersal, as well as to increase the chance of the species’ survival. In order for fertilization and fruit development to be successful, pollination must occur.

Pollination is the act of transferring pollen grains from the male anther of a flower to the female stigma, which sits at the end of the pistil (Image 1). Pollen gets transferred via wind, water, insects, birds, or other animals, including humans. Let’s break down the importance of pollination and the types of plants in your garden that heavily rely on pollinators, and those that do not.

What is a Fruit?

A fruit is simply the ripened ovary of the flower, which is responsible for protecting the next generation of seeds (which are developed ovules) prior to dispersal (Image 1). Fruit coevolved with birds and mammals as a means of effective reproduction and genetic variation, which aids in the plant’s survival during disease outbreaks or adapting to climatic changes. Humans eventually began selectively breeding fruiting plants in order to get larger, sweeter, and fleshier fruits.

 

Monoecious vs Dioecious Classification

Flowering plants are either classified as monoecious (maa·nee·shuhs) or dioecious (dy-EE-shus). The suffix -oecious comes from the Greek word oikia, meaning ‘house’.

Monoecious plants contain both male and female reproductive structures in the same flower, or house. Their flowers can be perfect (yellow flower, Image 2), which means that both male and female structures are present in the same flower, or imperfect (blue and red flowers, Image 2), in which the same plant species contains both male and female flowers with their own individual reproductive structures. These flowers can be pollinated via wind, water, insects and animals, but can also self pollinate using gravity. Pollen can be transferred via gravity, or with the aid of buzz pollination, which allows pollen to drop from the male anther to the female stigma.

Dioecious plants contain all female flowers in one plant, or ‘house’, and all male flowers on another. These plants require physical means of fertilization, carried out most efficiently by insects, along with wind and other animals. Honeybees, for example, collect nectar from male flowers, and pick up pollen granules along the way. As they travel to female plants for more nectar, they transfer pollen to the stigma, the receptive part of the female reproductive organ.

 

Classifying Common Fruiting Plants

It may be helpful for you to identify which plants in your garden may need additional aid in the pollination process. Most of the fruiting plants that we grow in our gardens are monoecious, which will contain either perfect or imperfect flowers.

Hand-pollinating imperfect flowers is recommended to ensure prolific fruit development and a bountiful harvest, especially if there is not an abundance or variety of pollinators near your garden. Even hand pollinating perfect flowers, for example, will increase the chances of successful pollination, and can increase overall yield and fruit size.

Here is a link from CSU extension explaining Hand Pollination.

Written by Kara McNab

References

Haynes, C. (2009, February 4). Botanical Terminology: Flowers, Houses and Sexual Reproduction. Yard and Garden. https://yardandgarden.extension.iastate.edu/article/2009/2-4/monoecious.html

The Birds and the Bees. (2022, December 7). US Forest Service. https://www.fs.usda.gov/managing-land/wildflowers/pollinators/birds-bees

U.S. Department of Agriculture. (2022, December 6). What is Pollination? US Forest Service. https://www.fs.usda.gov/managing-land/wildflowers/pollinators/what-is-pollination