What to Put Around the House: Rocks or Mulch?

Durability

• Rocks are more durable than mulch and therefore don't need to be replenished. Mulch gets absorbed by the soil gradually over time, especially with rainfall. As a result, it needs to be replenished annually. Rocks don't require hassle or upkeep. However, that durability comes with a downside. If rocks fall out of their designated areas and land in the lawn, which is common in rain and wind storms, they can badly damage lawn mowers and other equipment. Mulch does not have this liability.

Nutrients

• If you wish to support new growth in your garden, mulch is the preferable option. While plants are capable of growing through rocks, the rocks do not supply any nutrients to them. Rocks do anchor a plant to help prevent it from blowing away while also helping the soil retain moisture, yet mulch does this as well. Conversely, mulch also helps feed growing plants and provides a more welcoming environment for plant growth.

Scent

• Rocks are typically odorless whereas some mulch varieties have an unpleasant smell, depending on the ingredients. Some people use manure for mulching purposes and while this may support plant growth, it has a strong smell of fecal matter that takes time to dissipate. Mulch made from wood, grass clippings and other organic materials also can develop odor over time as bacteria breaks it down, but it won't be as strong smelling as manure. Flowers help to counteract this problem but rocks don't have this issue at all.

Maintenance

• Rock has the advantage of maintaining its color over an extended period of time while mulch's appearance changes as it's affected by weather conditions. Both are susceptible to wind disruption but it is more important to ensure rocks don't blow into the lawn than regular mulch so small varieties (like lava rock) require more general inspection. Mulch also needs to be renewed periodically, typically once a year, with a new layer added to retain appearance and effectiveness. Mulch also attracts insects while stone does not.