Watering Guide

Watering Technique:

Improper watering kills or injures more houseplants than any other cause. Over-watering, which can cause root rot, is just as harmful to your plants as under-watering. Designed to monitor your plant’s moisture levels, the Thirsty Light will tell you when it’s time to water. However, proper watering technique is just as important as knowing when to water. Here are some helpful watering hints for the best results with your indoor plants:

  • Use a watering can with a small spout for maximum precision and minimum mess.
  • Pour water evenly over the surface of the soil until it comes out of the drainage holes.
  • Use distilled, tap, or rainwater. Avoid using softened water, as it contains salts that can harm plants over time and affect the accuracy of the Thirsty Light.
  • Always use tepid water, never hot or cold.
  • Don’t allow plants to sit in standing water for more than an hour.
  • Potted houseplants should always have good drainage. Occasionally, roots can clog the pot’s drainage hole. Check the hole by pushing a stick or pencil into it.
  • Houseplants need a good washing of leaves periodically to remove dust.
  • Soil that is either too wet or too dry can lead to poor plant growth, or ultimately, death. Never water any plant unless it needs it.

Plant Cultural Preferences:

When you purchase a houseplant, it usually comes with a “cultural preference” label that describes optimal conditions, watering designation, and humidity requirements that can help refine your plant care. The three most common watering designations are:

Thoroughly moist:

Moisture-loving plants require excellent drainage, frequent watering and their soil maintained at a rich moisture level - never soggy, which can cause the plant’s root rot. Because the plant’s soil should not become dry between watering, the Thirsty Light is not an ideal monitor for these plants. Some examples are:

Bamboo Palm

Evenly moist:

Average moisture plants enjoy frequent watering and good draining soil. Their soil should be allowed to just dry out between watering and they should never be allowed to sit in standing water for more than an hour. Water them as soon as possible after the Thirsty Light’s LED Alert begins blinking. Some examples are:

Wandering Jew
Rubber tree
Spider plant

Drench Then dry:

Arid environment plants require less frequent watering. The Thirsty Light can reach the “completely dry” mode before watering. Some examples are:

Prickly pear cactus*
Jade plant
*Since most cacti are dormant in the winter and require little to no water, you can remove or turn off the Thirsty Light during this time.


Many plants require humid environments in order to thrive, which is unrelated to their cultural preference. Accommodate these plants with frequent misting or by keeping them in a greenhouse.