Gardening glossary
Soak and drain
Soak and drain — sometimes called "deep watering" or "flushing" — is the watering method most healthy houseplants and container vegetables prefer. The idea is simple: when it is time to water, water properly. Pour evenly across the soil surface until water flows freely out of the drainage holes for at least a few seconds. Then stop, let the pot drain completely, and do not water again until the substrate has dried to the depth that species tolerates.
The two halves of the name matter equally. The **soak** rehydrates the entire root ball, not just the top layer, and physically flushes accumulated fertiliser salts out of the medium. The **drain** prevents the roots from sitting in standing water, which is what actually causes root rot — not the act of watering deeply.
How to apply it:
- **Aroids, ferns, peace lily:** water when the top 2–3 cm of soil is dry. - **Succulents, cacti, snake plants:** wait until the substrate is bone dry top to bottom. - **Vegetables in containers:** water when the top 1–2 cm starts to dry, usually daily in summer.
Always empty the saucer 15 minutes after watering. Soil that wicks water back up from a full saucer effectively never drains, which defeats the entire method.
Soak and drain pairs naturally with a moisture meter or the finger test, because it removes the calendar from the equation. You water based on what the plant needs, not what day it is. This is the default routine I recommend in the Growli app for most foliage plants — adjusted up or down by species, pot material, and season.