While "shower mature thumbs" isn't a single standard term, it combines two essential concepts for experienced ("mature") plant enthusiasts: the technique for deep hydration and the continued cultivation of a "green thumb" as one ages.
Showering your indoor plants is a pro-level move to mimic natural rainfall. It deep-cleans foliage to improve photosynthesis and provides a thorough soak for the soil. shower mature thumbs
Place plants in a bathtub or shower. For large plants, use the showerhead; for smaller or more delicate ones, a sink sprayer or a gentle "rainfall" setting is best. While "shower mature thumbs" isn't a single standard