“Soaking,” often referred to as bottom watering, is an effective method for hydrating succulents that mimics the deep, infrequent rain they receive in arid environments. This technique involves placing a potted succulent into a shallow basin of water, allowing the substrate to absorb moisture upward through the pot’s drainage holes by capillary action. This strategy encourages the development of deeper, stronger root systems as roots grow toward the moisture source. Soaking also helps preserve the plant’s protective waxy coating (farina) and prevents water from pooling in leaf rosettes, which can lead to fungal issues.
The Science of Succulent Hydration
Succulents have evolved adaptations to survive long periods of drought, primarily through the storage of water in their fleshy leaves, stems, or roots. This water is held within cells called parenchyma tissue, allowing the plant to act as a reservoir. When a succulent is thirsty, it draws on these reserves, which is why its leaves may appear slightly deflated or wrinkled before watering.
The root systems of these plants are often fine and shallow, designed to quickly absorb light rainfall, but they benefit from deep saturation. Many commercial succulent soil mixes contain materials like peat moss that become severely hydrophobic when completely dry. This causes top-watering to simply run down the sides of the pot without wetting the root ball. Soaking fully rehydrates this dry, water-repelling substrate, ensuring the entire soil column is uniformly saturated and promoting robust growth.
Determining the Soaking Duration
The ideal duration for soaking a succulent generally falls within a range of 15 to 45 minutes. The goal is to allow the entire soil mass to become completely saturated without leaving the plant submerged indefinitely. A small, dry succulent in a plastic pot may finish absorbing water in about 15 to 20 minutes due to the material’s non-porous nature.
In contrast, a large plant in a porous terracotta pot filled with a gritty substrate may require 30 to 45 minutes, or sometimes longer, to fully draw up moisture. The soaking process is complete when the top surface of the soil visibly changes color and appears moist to the touch. This visual cue confirms that water has wicked up through the entire pot, indicating maximum hydration. The total time varies significantly based on the starting dryness of the soil and the pot’s material, making soil surface observation the most reliable indicator.
Post-Soaking Procedures and Drying Time
Once the top layer of soil is saturated, the pot must be promptly removed from the water basin to halt the absorption process. The next step is to ensure complete and efficient drainage of any excess water from the bottom of the pot. Allowing the plant to sit on a wire rack or elevating it for an hour or two helps prevent the bottom layer of soil from remaining waterlogged.
The period following the soak is important, as the soil must be allowed to dry out completely before the next watering cycle. High humidity, low air circulation, and the use of plastic pots slow down this drying period significantly. Terracotta pots are porous and allow moisture to evaporate through their walls, accelerating drying compared to non-porous containers. Providing good airflow and adequate light exposure promotes faster evaporation and prevents the anaerobic conditions that lead to root rot.
Recognizing Signs of Over- or Under-Soaking
Learning to read the physical signs of your succulent is the best way to determine if your soaking duration is appropriate. A plant that has been under-soaked, or left too long between watering, will display symptoms of dehydration as it consumes its stored water reserves. This typically manifests as shriveled, wrinkled, or deflated leaves, starting with the older, lower leaves as the plant sacrifices them to conserve moisture.
Conversely, a succulent that is over-soaked or watered too frequently will exhibit signs of cellular damage from excess water retention. The leaves will appear mushy, puffy, or translucent. If the condition progresses, the plant may develop black or brown spots on the stem or leaves, which indicate fungal infection and root rot.