Watch out! Your glass watering globe can set your plant on fire
You may never have thought about it. A glass watering globe in your plant, sitting nicely on the windowsill — the sun shines on it, and you enjoy your coffee. But what if that same sun is slowly scorching your plant? It sounds far-fetched, but it is a real danger that many people don't know about: a clear glass watering globe in direct sunlight acts as a magnifying glass.
How does the magnifying glass effect work?
Clear glass, filled with water, focuses sunlight onto one point — exactly like a magnifying glass. This focused light can reach a temperature high enough to scorch plant leaves, or in extreme cases even ignite them. The risk is greatest with:
- Round ball-shaped globes in clear glass
- Direct strong sunlight between 11am and 3pm
- Dry light leaves or dry moss as ground cover
- Prolonged exposure
Internationally there are multiple documented cases where glass water globes have caused fires in homes — not just on plants, but also on curtains, shelves and carpets.
How do you prevent this?
Tip 1 — Choose a frosted watering globe
The Minismus watering globe is made from frosted plastic. The frosted surface scatters light instead of focusing it. No focus, no heat, no danger.
Tip 2 — Never place the globe in direct sunlight
Is your plant on a sunny windowsill? Place the globe on the shaded side of the pot. See also our comparison of terracotta versus frosted plastic watering globes.
Tip 3 — Move your plant before going on holiday
Going away? Place your plant in a room with indirect light. More tips about watering plants while on holiday in our holiday blog.
Which watering globes are safe?
- Clear glass round globe — high fire risk in direct sun — only use outside direct sunlight
- Frosted plastic (Minismus) — no fire risk — recommended
- Terracotta — no fire risk — recommended
- Ceramic — no fire risk — recommended
View the Minismus watering globe 6-pack →
View the Minismus XXL watering globes →
