Which of the following is a benefit of using mulch in landscaping?

Using mulch in landscaping provides several significant benefits, and one of the most important is its ability to help retain soil moisture. Mulch acts as a barrier that reduces evaporation from the soil surface, which is particularly beneficial during hot and dry weather conditions. By keeping the soil moist, mulch allows plants and trees to access the water they need for healthy growth, reduces the need for frequent watering, and helps maintain a more stable temperature in the soil.

The other options describe effects that are contrary to the advantages of using mulch. For instance, increased soil compaction is typically undesirable as it can hinder root growth and water infiltration. Promoting weed growth is also not a benefit; in fact, one of the key purposes of applying mulch is to suppress weeds by blocking light and creating a physical barrier that prevents weed seeds from germinating. Lastly, while mulch can provide insulation against temperature extremes, its primary role in aiding frost-sensitive plants is more about temperature regulation rather than insulation from heat. Overall, the use of mulch is best recognized for its moisture-retention properties, making it an essential component in effective landscaping practices.