The Vitavia Soil Thermometer measures the temperature of the soil and displays the ground temperature continuously to help manage growing. The temperature range covers from -20 to +60 Degrees Celsius, this thermometer is a vital accessory for any gardener as it is used to determine whether the soil is ready for planting, e.g. tomatoes require 15 and cucumbers require 18 Degrees. Simply position in the ground where you would like to plant your seeds for their best growing opportunities.