Why is fertilizing in early or late fall considered a poor practice?

Fertilizing in early or late fall can indeed lead to cold damage, making it a poor practice. During these seasons, plants are transitioning into dormancy or already dormant. Fertilizers provide nutrients that stimulate new growth. If new growth occurs late in the fall, the tender new shoots may not have enough time to harden off before cold temperatures arrive. This can leave them susceptible to frost damage or other cold injuries, ultimately harming the plant's health and vigor.

While it is important to provide the right nutrients at the right time, applying fertilizer during these critical transitional periods can disrupt the natural processes of dormancy in woody plants and other perennials, leading to weaker plants in the spring.