What is a potential drawback of using thick mulches of plant material in gardens?

Using thick mulches of plant material can indeed encourage the development of damaging pests, which is a significant consideration in Integrated Pest Management (IPM). While mulches serve various beneficial purposes, such as moisture retention, weed suppression, and improving soil quality, their dense nature can create an environment conducive to certain pests.

For instance, organic mulches may decompose and become a habitat for pests like slugs and insects, which thrive in moist, organic matter. The accumulation of organic material can also lead to the harboring of diseases if the mulch is not properly managed. Thus, while mulching is beneficial for many reasons, the potential for creating an environment that supports pest populations is a valid drawback that gardeners should consider.