Watering globes, typically glass or plastic bulbs with long stems, provide a simple, passive solution for irrigating houseplants and container gardens. They deliver a steady supply of moisture, appealing to busy owners or those traveling briefly. Determining which plants benefit depends entirely on their natural habitat and moisture preference.
How Watering Globes Function
Watering globes regulate water flow using physics. When the water-filled globe is inserted into the soil, water trickles out, saturating the surrounding soil. This saturation creates a weak vacuum inside the globe, which stops the continuous flow and prevents the pot from flooding.
The device releases water only as the soil begins to dry out, making it a self-regulating system. When the soil dries, air enters the stem, breaking the vacuum and allowing a small amount of water to trickle out. This cycle ensures the soil remains consistently moist but not saturated.
Ideal Candidates for Consistent Moisture
The steady hydration provided by a watering globe is perfect for plants that naturally thrive in environments requiring non-stop moisture and suffer quickly if their roots dry out. Tropical houseplants are excellent candidates because they are accustomed to the consistent moisture levels of a rainforest understory. These plants often have high transpiration rates and relatively shallow root systems, making them susceptible to stress from even brief periods of dryness.
Examples of Ideal Candidates
Many common houseplants and container plants benefit from this method:
- Peace Lilies (Spathiphyllum), which are known to dramatically wilt when thirsty.
- Ferns (e.g., Boston or Maidenhair), which require constant humidity to prevent frond browning.
- Foliage plants like Pothos (Epipremnum aureum), Philodendrons, and Calatheas.
- Flowering annuals such as Impatiens and Begonias, whose rapid growth requires substantial, steady water intake.
- Herbs like basil, mint, and parsley, which benefit from uninterrupted soil moisture.
When Watering Globes Are Not Recommended
The constant moisture supplied by a watering globe is detrimental to plants that require a distinct drying period between waterings. Plants adapted to arid or semi-arid climates, such as cacti and most succulents, are prime examples. These plants store water in their leaves and stems and are highly susceptible to root rot if the soil remains wet for too long. The steady water release prevents necessary air circulation around the roots.
Epiphytic plants like orchids, which grow attached to trees, also have specialized aerial roots that must dry out completely between periods of moisture. Using a globe in their fast-draining media will likely keep the roots too wet, leading to decay. Plants with deep taproots or those that undergo seasonal dormancy, such as certain bulb varieties, are also poor choices, as constant moisture disrupts their natural growth cycles.
Proper Placement and Usage Tips
Successful use of a watering globe depends on proper setup and correct plant selection. Before insertion, the soil should be pre-moistened; dry soil will rapidly absorb the water, causing the globe to empty too quickly. A well-draining soil mix is necessary to ensure the moisture is distributed evenly and does not lead to waterlogging.
The globe’s stem should be inserted gently, ideally using a pencil or dowel to create a guide hole first. This prevents the stem from clogging with dirt or breaking. Placement should be near the edge of the pot, away from the plant’s main stem or crown, to avoid saturation that can lead to stem rot. Match the globe size to the pot size; a larger globe suits a big container, while a small globe is better for compact pots.