- Author: Gayle Nelson
When we look at a plant or tree, the bright foliage, tempting fruit or majestic stature might be the first thing we notice. But quietly humming along are the root systems that make all of these things possible.
Most roots live below ground and are difficult to observe firsthand. However, they possess incredible abilities. A closer look at these marvelous plant structures can enhance our appreciation of them.
Roots absorb water and other nutrients to nourish the entire plant. Some have microscopic hair-like structures that penetrate deep into the smallest spaces, increasing the surface area and reach of the main root system. These fine root hairs may also team up with organisms in the soil such as beneficial fungi and bacteria. They can help the plant survive and thrive in changing conditions. Ground-hugging species such as chamomile help anchor and stabilize plants in the soil.
Densely rooted systems form tight connections that can hold soil particles together. Gardeners faced with eroding soils and steep slopes might consider plants of this sort. Some species, such as mesquite, have roots that plunge dozens of feet deep in search of nutrients. While annuals and yearly vegetable crops might be content with the first few inches of soil, deeply rooted vines and trees need more depth to thrive.
Roots also store sugars and starches. Familiar examples include carrots, beets and potatoes. Each of these vegetables is known for its ability to be stored for a long time. Nutrients stored in these roots help feed future leafy plants.
Grafted trees and vines such as apple trees and grapevines sometimes produce small shoots at the base or even some distance away. These “suckers” are from the rootstock. Keep this habit in mind when siting new plants in your landscape. Grafted plants and trees with vigorous rootstocks may wreak havoc.
You have probably noticed the aerial roots on orchids and spider plants. These roots typically grow above-ground and can serve as an anchor or structural point. Epiphytes—plants that rely on other plants for support but not for nutrients—are common, low-care houseplants and may be a good option if you have limited space or time.
The science of roots is still unfolding. To get the most out of the roots in your landscape, be sure to have a plan before planting trees or other root-intensive species. Soil, nutrient availability and the cultivar can determine how easily roots become established. If you have compacted or heavy clay soil, amend it before planting.
Roots compete for space and nutrients, so putting plants too close together can limit growth of some species. Some roots, such as black walnut roots, exude chemicals that keep other plant roots at bay. Think carefully choosing such plants for your landscape.
Before planting perennials or trees, consider how their roots will manage in the event of drought. Extensive root systems too close to sidewalks can also cause problems. And deep-rooted trees and shrubs can interfere with septic systems and underground water pipes. Keeping these possibilities in mind can minimize future landscape issues and help your garden thrive.
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. U. C. Master Gardeners of Napa County ( http://ucanr.edu/ucmgnapa/) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4143, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County.