Plants are amazing energy producers, creating the foundation for our natural ecosystems by capturing the sun’s energy and transforming it into biomass that can be shared with all. From humans to wildlife, this process is essential to all that exists on Earth.
In today’s world, filled with an ever-expanding network of solar arrays that capture the sun’s energy for our own use, it's easy to overlook the everyday leaves we see around us. However, these plant parts are perhaps one of the most important aspects of life’s evolutionary history on Earth. The origin of photosynthesis, the chemical process by which plants translate the sun’s rays into energy, is the original solar energy storage method on our planet and remains the top energy-producing process to date, dwarfing the amount of solar energy that human engineering collects on an annual basis.
Plant energy production in a nutshell
Photosynthesis is the chemical process by which plants use sunlight, along with carbon dioxide and water, to create energy in the form of sugars, which are highly energetic molecules that can be tapped later for use by the plant. These sugars are primarily stored as starch in root structures, but can be found tucked away in lots of other parts of the plant. Sugars can be found throughout the conductive tissue of the plant, referred to as the xylem and phloem, which is located just inside the bark of woody plants. In addition, sugars are also tucked away throughout the plant in thin-walled, living cells called parenchyma cells, which are part of nearly every plant tissue.
It’s absolutely amazing to me that plants can collect light and transform it into usable energy; however, an equally remarkable process is their ability to store this energy for later use. This time of year, as the plant world transitions to winter dormancy, I often contemplate this energy storage process, as well as its reuse in spring. Whether we realize it or not, gardeners are regularly interacting with this process since many of the plant management practices we follow are built around the preservation, storage, or later use of energy.
Gardening practices focused on plant energy.
The timing for pruning woody plants is one way that gardening practices preserve the solar energy plants store throughout the growing season. By pruning trees and shrubs during the dormant winter season, the impacts of our pruning on the plant’s energy stores are minimized. Conversely, pruning at the wrong time of year, such as during leaf out or flowering, may unnecessarily take away some of the plant’s energy with every pruning cut.
While the timing of pruning may help conserve energy, woody plant propagation from dormant cuttings is a clever way we have learned to utilize stored energy for the production of new plants.
In this method, twigs are removed from the plant during the dormant season that have at least one node (or growing point) near the tip of the twig and one node near the base. The cuttings are then “planted” into pots (or the ground) in the same orientation they were on the plant. Upon exposure to soil, moisture, and appropriate temperatures, the node at the bottom of the cutting will gradually develop roots, and the upper node, or nodes, will begin to grow leaves. Believe it or not, the twigs on many plants have enough stored energy to produce a whole new root system and leaf canopy that will develop into an entirely new tree or shrub.
Learn to use plant energy for propagation.
Many common landscape shrubs can easily be propagated from cuttings or other methods. If you are interested in using this year’s stored solar energy to produce new plants next year, join me for a woody plant propagation workshop at Allerton Park and Retreat Center on Wednesday, December 10th, 2025.
Participants will learn about the various plant processes involved in different methods of woody plant propagation, and everyone will leave with dormant cuttings to propagate at home this winter. For more information and registration, please visit go.illinois.edu/PropagationWorkshop.
Ryan Pankau is a University of Illinois Extension Horticulture Educator serving Champaign, Ford, Iroquois, and Vermilion Counties.