Coco liners, made from coconut husk fibers (coir), are commonly used in wire-frame hanging baskets and planters. While they offer a natural look and excellent aeration, their highly porous nature causes rapid moisture loss. This tendency means special preparation and care are necessary to keep plants hydrated and healthy.
Why Coco Liners Dry Out Rapidly
The rapid drying of coco liners stems from the material’s structural design and open-air exposure. Coir fibers are naturally coarse and highly porous, which facilitates excellent drainage and prevents root rot. This porosity, while beneficial for aeration, allows water to drain away almost instantly after irrigation.
The high surface area of the fiber, combined with the basket’s exposure to air and wind on all sides, accelerates the rate of evaporation. Unlike solid plastic containers, moisture in a coco liner is wicked away through the sides and bottom. Wind passing over the basket acts like a fan, continuously stripping moisture from the exposed fibers and the soil within.
Pre-Planting Moisture Preparation
Addressing rapid drying begins before planting by overcoming the initial hydrophobicity of dry coir. A completely dry coco liner can repel water slightly, causing it to run straight through without wetting the fibers. To counteract this, the liner must be thoroughly soaked, ideally by submerging it in a tub of water for at least 30 minutes to ensure full saturation.
Once the saturated liner is placed in the basket frame, focus should shift to the potting medium. Use a high-quality potting mix that includes ingredients known for their moisture-retaining properties, such as peat moss or compost. For greater water retention, polymer crystals or water retention gels can be incorporated directly into the soil mix. These superabsorbent polymers hold water and slowly release it back to the soil as it dries.
Adding Physical Barriers to Reduce Evaporation
The most effective way to combat moisture loss is to introduce a physical barrier between the porous coir and the soil. A simple technique involves lining the inside of the basket with a thin sheet of plastic, such as a trash bag or cling film. The plastic acts as a vapor barrier, preventing wind from wicking moisture out through the sides of the liner.
It is necessary to pierce the plastic barrier with several drainage holes at the bottom to ensure excess water escapes and prevent the soil from becoming waterlogged. Alternatively, materials like landscape fabric, an old cotton T-shirt, or dampened sphagnum moss can be placed between the coir and the soil. This intermediate layer slows water flow and reduces the surface area available for evaporation without completely blocking drainage.
Optimizing Watering and Placement
Once the basket is planted, ongoing maintenance routines must be adjusted to suit the liner’s characteristics. When watering, apply water deeply and slowly until it begins to drip from the drainage holes. For severely dry baskets, the “dunking” method is highly effective: submerge the entire basket in a large container of water until the air bubbles stop rising, indicating full saturation.
The time of day for watering impacts moisture retention, with early morning being the preferred time. Watering then allows the plants to absorb the water before the heat of the day increases the evaporation rate. Adjusting the basket’s location can also significantly reduce water stress. Placing the containers away from strong, consistent wind currents limits the accelerated evaporation caused by air movement. Baskets should also be positioned in partial shade, away from the intense afternoon sun, to further conserve soil moisture.