You’ve likely come across numerous claims online regarding the effectiveness of using ice cubes to water your houseplants. However, you can’t simply place a few cubes in your plant pots – different plants have different watering requirements, and many plants may not even like ice-cold water.
You can water some plants with ice cubes, but it is not a suitable watering method for all container plants. When watering with ice cubes, use two ice cubes per pot – each measuring 2 inches high, 2 inches long, and 2 inches wide (5x5x5 cm) – to water a plant in a pot 6-10 inches (15-25 cm) wide and 10 inches (25 cm) deep. The frequency and the number of ice cubes will vary depending on the type of plant and the weather.
This article will discuss how to use ice cubes on plants, the pros and cons of this method, and which plants can and cannot benefit from it.
Benefits: Convenience and Limited Risk of Overwatering
Many new gardeners love collecting and keeping plants, but lack the skills, time, and knowledge to care for them properly. As a result, they look for easy ways to tend to their young garden. One such gardening hack quickly gaining popularity is watering with ice cubes.
Its popularity stems from its many benefits, including:
Putting ice cubes on the soil is easy and time-efficient. You can simply place them on the soil and forget about it, allowing you to keep your plants properly watered without fuss.
Reduced Risk of Overwatering
The slow melting of the ice cubes provides a low but steady supply of moisture to the soil in small amounts, protecting the plant from the dangers of overwatering.
Neat and Regulated Water Supply
Using ice cubes to water plants also prevents water from splashing which could cause leaf spots on some plants with sensitive leaves.
Plants that Benefit from Ice Cube Watering
Although most plants prefer water at room temperature (68-77 °F or 20-25 °C), there are some plants that have been proven to benefit from water from melting ice cubes.
The one group that can benefit from this method, with evidence backed by science, are orchids.
Since the recommendation of watering orchids with ice cubes became popular, studies have been conducted into the effectiveness of this method. They found that watering orchids with ice cubes had no adverse effects on growth when applied correctly.
Orchids are tropical plants that are sensitive and prone to overwatering, making the ice cube method ideal for them. There aren’t enough long-term studies to support the use of this technique on orchids, but short-term results are positive.
Drawbacks: Cold Water Can Cause Damage to Your Plants
To help you decide whether or not it’s worth trying the ice cube method on your plants, you will also need to understand the disadvantages or risks that come with it:
The Cold Can Prevent Chemical Reactions in the Soil
Although chemical reactions can help generate heat to increase the soil temperature, too much ice water can prevent these chemical reactions from happening.
Some soil enzymes depend on heat to facilitate or initiate a reaction. The cold from the ice water can deactivate the enzymes, resulting in plants being unable to process or utilize the nutrients in the soil.
The Cold Can Slow Growth
Many flowering plants rely on environmental signals like temperature to help them complete their life cycles. Cold temperatures lead to slower growth, allowing the plant to focus on survival over the cooler months.
During the cold winter, these plants may become dormant or limit new growth. This cold period is necessary to help plants prepare for budding and blooming in spring. Some plants may delay their blooming period or even fail to produce flowers without this period.
Melting ice releases cold water into the soil. When the roots feel the cold in the soil, they adjust to this change in temperature by slowing growth. Constant exposure to the cold can eventually give the plant the impression that it is winter, compelling it to go into dormancy.
Certain Plants Are Susceptible to Cold Damage
You will find many plants can suffer irreversible damage when watered with ice cubes.
Here are some plants you should avoid using ice cubes on:
- Plants with taproot systems
- Plant in small pots
Succulents are plants that love heat and struggle to absorb the cold water coming from the melting ice. Also, contact between the ice and the fleshy leaves of succulents can cause physical damage to the leaf surface.
Plants With Taproot Systems
Depending on the water retention capacity and the texture of the soil, plants with taproot systems may not absorb the water coming from the ice cubes. Clay soil, for instance, is not porous enough for moisture to penetrate deeply into the soil, limiting the roots’ access to water.
Plants in Small Pots
The limited space in small pots will keep the plants in close contact with the ice cubes. This contact may result in leaf damage.
Unless the stem is long enough to prevent contact between the leaves and the ice cubes, it is best not to use the ice cube method to water plants in small pots.
Using Ice Cubes to Water Plants: Step-By-Step Guide
If you do want to give this method a try for your orchids, here’s how to get it right:
Use Two Cubes for Each Pot
Two large ice cubes per week should suffice when the environmental temperature is between 61-77 °F (16-25 °C). For larger pots over 10 inches (25.4 cm) in diameter, you may need to add one more ice cube for every 2-inch (5-cm) increase in size.
Keep Cubes Away From the Stem
When using ice cubes to water plants, it’s important to keep the cubes away from the plant to prevent damage or slowed growth. In doing so, you should also put the cubes on the soil near the edges of the pot. The ice water will warm up as it travels through the soil toward the plant’s roots.
Don’t Let the Ice & Leaves Touch
Try to prevent contact between the ice cubes and the leaves. Many plants have leaves that are sensitive to moisture or cold. Letting the leaves touch the ice cubes can result in irreversible leaf spots or discoloration in water and moisture-sensitive plants like African violets.
Check the Condition of the Leaves
The main reason for using ice cubes on plants is to avoid lack of or excess water. However, some plants may not absorb cold water, resulting in underwatering. Sometimes, the ice melts too quickly, resulting in overwatering.
Check the leaves for browning, yellowing, drooping, or drying. These signs will tell you whether or not your plants have watering problems.
Observe How Quickly the Ice Melts
Warmer temperatures will cause the ice to melt quicker. Check the soil a day after the ice completely melts to see if you need to add more. Use your fingers to dig an inch (2.54 cm) into the soil to check for moisture. If it is dry, you may need to add more ice cubes.
The standard when using ice cubes to water plants would be to use two large pieces around 2x2x2 inches (5x5x5 cm) in size for every pot 6-10 inches (15-25 cm) in diameter, 10 inches (25 cm) deep.
However, it is crucial to understand that not all plants can benefit from this method. Using ice cubes to water plants is an under-researched method. It is best to learn the pros and cons and weigh your options before using ice cubes on your precious plants.