Propagation Thermometer for Seed Germination – Celsius & Fahrenheit, 15cm

What is the Propagation Thermometer for Seed Germination?

It's a simple glass thermometer (with a plastic top) for checking the temperature inside seed trays, propagators, and greenhouses. It reads from -30°C to 50°C (and also shows Fahrenheit) and is spirit-filled—not mercury. It’s not waterproof, so use it as a dry tool and wipe clean.

How do I use the Propagation Thermometer to measure soil or air temperature?

Place it in the seed compost to check soil temperature or leave it in the dome to monitor air temp. Insert it roughly to seed depth, and give it 1–3 minutes to stabilise before reading. Always measure where the seeds or roots actually sit—not just the surface or air.

Can I use the Propagation Thermometer with a heat mat or in a greenhouse?

Yes—place it directly in the tray on top of the heat mat to monitor media temperature. It’s also useful in greenhouses, but not intended for permanent outdoor use. Check for hot spots by measuring different areas in the tray.

What temperature is best for seed germination?

Most common seeds germinate best between 18–24°C, but check your seed packet for specifics. Consistent temperature is key—big swings can slow or weaken germination, and the thermometer helps you keep things stable.

Can this thermometer help prevent issues like damping off or overheating?

It helps you monitor and adjust conditions to avoid extremes. Overheating from direct sun or poor airflow can cook seedlings or raise damping-off risk. This thermometer helps catch those problems early.

Can I use it for cuttings, compost, or aquariums?

Yes for cuttings—stable root zone temps help. For compost, it works in small bins but isn’t long enough for deep piles. It can measure water temp, but it’s glass and not aquarium-rated, so use with care.

Is the Propagation Thermometer durable and safe around kids or pets?

It's made of glass, so handle with care. Don’t leave it where it might be knocked over or chewed. If it breaks, clean up carefully and don’t touch the liquid. It’s best stored safely between uses.

How do I clean and store the Propagation Thermometer?

Wipe gently with a damp cloth—don’t soak it or use harsh chemicals. You can disinfect it with a mild wipe-down. Store in a dry, safe spot out of direct sun and away from anything that might crush it.

What’s the benefit of a glass thermometer over a digital one?

Glass thermometers don’t need batteries, don’t glitch, and offer reliable readings without electronics. Digital probes are faster and more precise—better for advanced setups—but for general seed starting, glass works well.

What’s the most common mistake when using a propagation thermometer?

Measuring the wrong spot—like checking air temp near the lid instead of the seed zone. For best results, check media temperature morning and afternoon, especially when using heat mats or sunny windows.