There are some trees and plants that inhibit the growth of other botanicals in their neighborhood. They act like noxious neighbors. We describe them as being allelopathic.
This word is derived from the Greek word "allelon," which means "to suffer." Allelopathic plants release chemicals through their leaves and roots that prevent the germination and/or growth of nearby plants. It is a hard problem to solve if you inherit, for example, a black walnut tree in the yard of a home that you purchase, as nothing you want to plant will grow near a walnut tree. The site will also not be good even after you chop down the walnut tree.
Sunflowers also have a small amount of a similar chemical but fortunately it is carried only in their seed hulls, which can be easily raked up and disposed of.
The pink flowering Mimosa (also known as Tree of Heaven) are trees that are especially toxic and should always be chopped down. Never allow one to grow in your yard as they spread their seeds in the wind and can infect an entire neighborhood.
You should also beware of eucalyptus, red cedar, red maple, and fragrant sumac.
Plants to avoid include desert sagebush, tobacco, sorghum, and Russian knapweed.
Other more benign items that should be planted in their own space and not near other plants are broccoli, lantana, and pea vine.
Like some children you may have known, they do not play well with others.
This is Moya Andrews, and today we focused on allelopathic items.
The National Champion Black Walnut (Juglans nigra) on Sauvie Island, Oregon.
Ascending the Giants, wikimedia