What is the main advantage of using mulch in ornamental plantings?

Using mulch in ornamental plantings primarily offers the advantage of reducing stress on the plants by conserving moisture. Mulch acts as a barrier, reducing evaporation from the soil surface, which helps maintain consistent moisture levels. This is particularly beneficial during hot and dry conditions, where plants can otherwise suffer from drought stress.

In addition to conserving moisture, mulch can also improve soil temperature and reduce competing weeds, which can further support plant health. While it may not completely eliminate the need for watering, especially in extreme weather conditions, it significantly reduces the frequency and amount of watering required.

The other options, while they may contain elements related to plant care, do not capture the most significant benefit associated with mulch. Mulch does not inherently speed up plant growth or serve only as decoration; instead, its primary role is to create a more favorable environment for plant establishment and growth.