Planting under trees - Ask Extension
We removed our lawn and want to plant a mix of shrubs and ground cover in that space. But almost half of this now-open space lies under a mature Japan...
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Planting under trees #891018
Asked December 26, 2024, 2:44 PM EST
We removed our lawn and want to plant a mix of shrubs and ground cover in that space. But almost half of this now-open space lies under a mature Japanese maple (about 15 ft. tall and 20 ft. wide) and a small saucer magnolia, plus a newly planted crepe myrtle that should grow into a roughly 10X10 ft. tree. We're wondering if we can freely plant shade-tolerant shrubs and ground cover anywhere and in any amount under these trees, or would planting a lot of shrubs and ground cover harm the trees, maybe add too many competing roots. Thanks for your help.
Benton County Oregon
Expert Response
Dear Bob,
Thanks for contacting us about planting under your trees. Nature uses layering of different types and sizes of plants, and you can, too. The key is to make sure each plant has both adequate vertical and horizontal space above and below ground.
Your task will be easier if the trees and understory plants are small. There is less chance of disturbing existing roots, and smaller plants will generally adapt better. Most of the feeder roots of a mature tree grow in the top 18-inches of soil, and can spread 2 to 3 times the width of the mature canopy. Avoid cutting the larger stabilizing roots of established trees.
Place shrubs at least two times their expected mature width away from the trees and each other. Ground covers may be planted closer, depending on their habit, but leave clear space for a couple of feet around the trunk so you can easily see and remove any unwanted suckers and maintain airflow. Saucer magnolias have shallow roots, so provide them with more space and take care to choose plants that do not have thick or aggressive roots.
The following article may give you some helpful information. (Note that it is from Pennsylvania Extension so some of the plants suggested may not be appropriate in Oregon.)
https://extension.psu.edu/underplanting-trees-respect-the-roots
Here is an additional article that may be useful:
https://pacifichorticulture.org/articles/planting-the-understory/
I hope this information is helpful. Please write again whenever you have gardening questions.
Thanks for contacting us about planting under your trees. Nature uses layering of different types and sizes of plants, and you can, too. The key is to make sure each plant has both adequate vertical and horizontal space above and below ground.
Your task will be easier if the trees and understory plants are small. There is less chance of disturbing existing roots, and smaller plants will generally adapt better. Most of the feeder roots of a mature tree grow in the top 18-inches of soil, and can spread 2 to 3 times the width of the mature canopy. Avoid cutting the larger stabilizing roots of established trees.
Place shrubs at least two times their expected mature width away from the trees and each other. Ground covers may be planted closer, depending on their habit, but leave clear space for a couple of feet around the trunk so you can easily see and remove any unwanted suckers and maintain airflow. Saucer magnolias have shallow roots, so provide them with more space and take care to choose plants that do not have thick or aggressive roots.
The following article may give you some helpful information. (Note that it is from Pennsylvania Extension so some of the plants suggested may not be appropriate in Oregon.)
https://extension.psu.edu/underplanting-trees-respect-the-roots
Here is an additional article that may be useful:
https://pacifichorticulture.org/articles/planting-the-understory/
I hope this information is helpful. Please write again whenever you have gardening questions.
Dear Bob,
Thanks for contacting us about planting under your trees. Nature uses layering of different types and sizes of plants, and you can, too. The key is to make sure each plant has both adequate vertical and horizontal space above and below ground.
Your task will be easier if the trees and understory plants are small. There is less chance of disturbing existing roots, and smaller plants will generally adapt better. Most of the feeder roots of a mature tree grow in the top 18-inches of soil, and can spread 2 to 3 times the width of the mature canopy. Avoid cutting the larger stabilizing roots of established trees.
Place shrubs at least two times their expected mature width away from the trees and each other. Ground covers may be planted closer, depending on their habit, but leave clear space for a couple of feet around the trunk so you can easily see and remove any unwanted suckers and maintain airflow. Saucer magnolias have shallow roots, so provide them with more space and take care to choose plants that do not have thick or aggressive roots.
The following article may give you some helpful information. (Note that it is from Pennsylvania Extension so some of the plants suggested may not be appropriate in Oregon.)
https://extension.psu.edu/underplanting-trees-respect-the-roots
I hope this information is helpful. Please write again whenever you have gardening questions.
Thanks for contacting us about planting under your trees. Nature uses layering of different types and sizes of plants, and you can, too. The key is to make sure each plant has both adequate vertical and horizontal space above and below ground.
Your task will be easier if the trees and understory plants are small. There is less chance of disturbing existing roots, and smaller plants will generally adapt better. Most of the feeder roots of a mature tree grow in the top 18-inches of soil, and can spread 2 to 3 times the width of the mature canopy. Avoid cutting the larger stabilizing roots of established trees.
Place shrubs at least two times their expected mature width away from the trees and each other. Ground covers may be planted closer, depending on their habit, but leave clear space for a couple of feet around the trunk so you can easily see and remove any unwanted suckers and maintain airflow. Saucer magnolias have shallow roots, so provide them with more space and take care to choose plants that do not have thick or aggressive roots.
The following article may give you some helpful information. (Note that it is from Pennsylvania Extension so some of the plants suggested may not be appropriate in Oregon.)
https://extension.psu.edu/underplanting-trees-respect-the-roots
I hope this information is helpful. Please write again whenever you have gardening questions.
