I have 3 Holly bushes in my front yard. For the past 2 years I have planted Mums near them. The Mums have died by the holly bushes, but have thrived in other places of the front yard. Are the Holly bushes killing my Mums?
Mums and Holly Bushes
If you're thinking of the way some plants, like black walnut, are known to "poison" the area around them to inhibit the growth of other plants, the answer is no. Hollies are not known to be allelopathic; in addition, mums are known to be resistant to such chemicals. However, it is highly likely that the roots of the hollies are "sucking up" all the water, causing the mums to fail. This article has more information on this interesting phenomenon: https://www.gardeningknowhow.com/garden-how-to/info/allelopathic-plants.htm