Garland Soil Thermometer
Garland Soil Thermometers are the ideal thermometer for use with soil, compost, seed beds and plant growing. They're especially suitable for heated seed beds and mushroom growing, confirming if the growing medium is at the optimal temperature. It also lets you determine if ground soil has adequately warmed up for spring planting.
This handheld compost thermometer has a metal casing so you can push it directly into hard soil. (Use a screwdriver to make a hole if you're concerned about rocks.)
The thermometers were much better than expected. They are sturdy, the metal "sleeve" will protect it from damage.