Mulch – The Good, The Bad, and the Water-Repelling Truth
Mulch – The Good, The Bad, and the Water-Repelling Truth
Published by Urban Garden Solutions
Mulch is one of the most valuable tools in the landscape world. It suppresses weeds, moderates soil temperature, improves soil structure, and gives your beds a finished, well-maintained look. But like any tool, mulch must be used wisely. Improper application or lack of maintenance can turn mulch from a plant protector into a plant stressor.
The Benefits of Mulch (When Done Right)
Moisture Retention: Helps the soil hold water longer, reducing evaporation and irrigation needs.
Weed Suppression: Blocks sunlight to weed seeds, reducing unwanted growth.
Temperature Regulation: Insulates plant roots from extreme heat and cold.
Soil Health: Organic mulch breaks down over time, improving soil structure and feeding beneficial microbes.
Aesthetic Value: Gives a clean, uniform appearance to your landscape beds.
When Mulch Goes Wrong
Over time, even good mulch can create problems if not managed properly:
1. Hydrophobic Mulch (Water-Repelling)
Aged mulch, especially shredded hardwood, can become hydrophobic, repelling water instead of allowing it to soak through. This leads to dry roots and stressed plants, even if you water regularly.
What to look for: Water pooling on top of mulch or running off instead of soaking in.
2. Fungal Growth and Mycelium Layers
When mulch dries out too much or has poor airflow, it can develop a white fungal mycelium layer. While some fungi are natural decomposers, a thick mat of mycelium can reduce gas exchange in the soil, limiting root respiration and creating an unhealthy root environment.
What to look for: White web-like growth under the mulch, especially in dry or compacted areas.
3. Trapping Too Much Moisture with Drip Irrigation
Drip irrigation under a thick mulch layer can sometimes lock in too much moisture, especially in clay-heavy soils. This can lead to fungal issues, root rot, or stressed plants that never fully dry out between waterings.
In poorly draining clay soils—especially common in new construction sites—mulch can also form a hard, crusty surface over time. This crust blocks water and air from reaching the soil below, compounding the stress on young plants.
What to look for: Wilting plants, sour or musty mulch smell, mushrooms, or fungal growth.
4. Mulch Build-Up Over Time
Reapplying mulch year after year without removing the old layer can lead to too thick beds. This prevents water and oxygen from reaching plant roots and can suffocate them over time.
What to look for: Mulch layers over 3 inches thick, stiff or crusty surface texture.
Over time, even good mulch can create problems if not managed properly:
The UGS Approach to Smart Mulching
At Urban Garden Solutions, we treat mulch like any other part of your landscape: with purpose and precision. Our mulch services include:
Mulch depth evaluations
Seasonal top-ups only when needed
Removal or breaking up of hydrophobic mulch
Monitoring of irrigation efficiency in mulched zones
Final Thought:
Mulch is a great tool when used correctly. With the right application and maintenance, it can support a healthy, thriving landscape. However, it can quietly cause water stress and plant decline when ignored or over-applied.
Do you need help with mulch maintenance or irrigation evaluation? Let Urban Garden Solutions ensure that your mulch is helping, not hurting.
Urban Garden Solutions
Smart Plant Care | Soil-Focused Solutions | North Texas Experts
