Wednesday, January 17, 2024

A mysterious water drop (or two) on houseplants?! by Vicky Spelman


I found a drop of water on the tip of one of my dieffenbachia's leaves.  What?  I checked to see if there was a ceiling leak.  Thank goodness no, but... then what caused this water drop?  

If you find some water drops on some of your houseplant’s leaves, it is usually caused by one of three things:

1. Transpiration:  It is the process of water moving through the plant and its evaporation from the leaves.  Leaves drip when they have as much moisture as they can hold.  This is the main cause of water drops on plants.  If this is becoming a common occurrence, consider reducing water to the plant.

 The Spruce / Fiona Campbell

2. Dew: Condensation can occur when the air around the plant cools down. It is more likely to happen in the warmer months with open windows causing temperature differences in the air and the plant.  As the temperature drops, water vapor in the air turns into liquid and forms dew on the plants.  Most of the time it is reabsorbed by the plants’ leaves.  More commonly seen on outside plants in the early morning.

iStock / Marina Krisenko

Pinterest / Morning Dew on Grass

3. Guttation:  Pressure relief for plants – tiny water drops spaced uniformly around margins of a leaf.  Unlike transpiration, however, guttation results in multiple water droplets appearing across the plant.  With nighttime conditions of cool air, high humidity and warm soil, root pressure can move water to the leaves.  

University of Missouri / droplets on a tomato leaf in a greenhouse

Guttation / Noah Elhardt, Public domain

The amount of water a houseplant needs could change throughout the year.  Check your plants' health and your watering habits.