Mulch
/mʌltʃ/
Definition
Mulch refers to a layer of material spread on the soil surface around plants or over planting beds. It is a gardening material and covering, not a soil amendment mixed into the ground. Common types include organic materials such as bark, leaves, or straw, and inorganic materials such as gravel. This surface layer helps separate the soil from open air, which affects moisture loss, temperature, weed growth, and soil splash.
Use in Gardening
- Moisture buffering: Mulch slows evaporation from the soil surface, which helps roots stay more evenly moist between waterings and can reduce stress during hot or windy weather.
- Temperature moderation: A surface layer insulates the root zone. It helps keep soil cooler in summer and reduces rapid temperature swings that can disturb shallow roots.
- Weed suppression: By blocking light, mulch limits many weed seedlings before they establish. Fewer weeds means less competition for water and nutrients around garden plants.
- Soil improvement over time: Organic types gradually break down and add organic matter, which can improve soil structure and support beneficial soil organisms such as earthworms and microbes.
- Placement matters: Mulch should be kept away from trunks and stems. Piling it against plant bases can trap excess moisture and increase the risk of rot or pest problems.
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