The practice of soaking, often called bottom watering, is a technique used to thoroughly and evenly hydrate a potted plant’s soil. This method involves placing the pot directly into a container of water, allowing the potting medium to absorb moisture from the bottom up through capillary action. Unlike standard top watering, which can be inefficient if the soil is overly dry, soaking ensures uniform saturation. This approach is primarily reserved for plants that are severely underwatered or those whose soil has developed a resistance to water penetration.
Identifying the Need for Soaking
This technique becomes necessary when the potting medium becomes hydrophobic, meaning the soil particles repel water instead of absorbing it. This condition often results from the buildup of waxy organic compounds that coat the soil particles, preventing moisture infiltration. A telltale sign of hydrophobic soil is when water poured from the top immediately pools on the surface or races down the pot wall, quickly exiting the drainage holes without moistening the interior.
A practical way to determine if a plant needs a deep soak is by lifting the container. If the pot feels significantly lighter than it should after a recent watering, it indicates that little water was retained by the soil. Another diagnostic cue is the visual inspection of the soil pulling away from the edges of the pot, which happens when the root ball shrinks due to severe dehydration.
Step-by-Step Soaking Procedure
To begin the soaking process, select a clean container, such as a tub, sink, or deep saucer, that can accommodate the plant pot. Fill this container with lukewarm or room-temperature water, as cold water can shock the plant’s root system. The water level should reach approximately one-half to three-quarters of the way up the side of the pot, but it should not overflow the rim.
Carefully place the potted plant, ensuring it has drainage holes, into the water-filled container. As the water is drawn up through the drainage holes and into the soil, small air bubbles will rise to the surface, signaling that air pockets are being replaced by water. This upward movement is driven by capillary forces, which distribute moisture evenly throughout the dry medium.
The duration of the soak typically ranges between 20 and 45 minutes, depending on the pot size and how dry the soil is. The most reliable indicator of complete saturation is when the top layer of the potting mix feels visibly moist to the touch. Once the entire surface of the soil appears dark and damp, the water has successfully wicked up to the top, and the soaking process is complete.
Ensuring Proper Drainage and Drying
Immediately after the soil has achieved full saturation, the pot must be removed from the soaking container to prevent the roots from sitting in stagnant water. The goal is thorough hydration, not waterlogging, which quickly leads to root suffocation and decay. Lift the pot and allow the excess water to flow freely out of the drainage holes.
To facilitate rapid and complete drainage, you can slightly tilt the pot or place it on a wire rack over a sink or tub. Placing the pot on a dry, absorbent material like a towel for a short period can also help wick away residual moisture from the bottom. This step is crucial because saturated soil displaces the oxygen roots need for respiration, fostering an anaerobic environment. Plants adapted to arid conditions, such as succulents and cacti, should be soaked sparingly and for shorter durations to minimize the risk of root rot.