Is high water retention beneficial for plants?
Written by
Nguyen Minh
Reviewed by
Prof. Martin Thorne, Ph.D.Water retention is a delicate balance in plant use. Moderate water retention allows plants to receive consistent moisture between irrigations, whereas excessive water retention can suffocate the roots. I have seen tomato plants flourish in a well-draining loam and become waterlogged in heavy clay during Utah's rainy season. Plants will require both water and oxygen at the root level.
Moderate Retention Benefits
- Reduces watering frequency by 30-50%
- Maintains consistent nutrient availability
- Supports steady root development
- Prevents drought stress during heat waves
Excessive Retention Risks
- Causes root rot from oxygen deprivation
- Promotes fungal diseases in wet conditions
- Leaches nutrients beyond root reach
- Stunts growth in waterlogged soil
Retention Adjustment Methods
- Add perlite to heavy soils for drainage
- Incorporate compost to sandy soils for retention
- Install drainage systems in problem areas
- Use moisture sensors to maintain ideal levels
Loam soils are at the ultimate balance with 40% sand, 40% silt, and 20% clay. Moisture can be held, but still drains. This is the texture of my most successful garden beds, which I eventually achieved by adding amendments to create similar conditions to those of the existing soil.
Use the squeeze test to determine moisture levels. Take a handful of soil and squeeze it. Ideal loam soil will form into a ball and crumble slightly when poked. Clay will hold shape and is poorly drained. Sandy soil will fall apart, indicating inadequate water retention.
Adjust retention to meet the plant's specific needs. My roses need better drainage than hydrangeas. Add a layer of coarse sand around your Mediterranean herbs. For moisture-loving plants, bring in more organic matter. Adjust the makeup of each bed according to its composition; avoid a one-size-fits-all approach.
Read the full article: 7 Proven Water Retention Soil Methods
