An analog soil thermometer with a 20-inch stem, the Reotemp 20 Inch Fahrenheit Backyard Compost Thermometer makes an ideal choice for composter beginners. With reliable readings, you can easily tell at a glance how hot your compost is, with three temperature zones to signify steady, active, or hot readings. And it even comes with a handy PDF composting guide for beginners.

It has a thicker, three-quarters of an inch diameter around the stem, so it's more durable and less susceptible to bending than some other thermometers. A longer stem allows for deeper placement in the center of your compost pile and therefore outputs more accurate readings. The temperature dial itself is hermetically sealed and won’t fog up, so it can safely be left in the pile overnight.

With an upper-temperature limit of 200 degrees Fahrenheit and a response time of a few seconds, no pile is too hot to handle for the Reotemp 20 Inch Thermometer, and you’ll get super-fast readings that you can rely on. Plus, reinforced construction means the dial won’t separate from the stem, so you can reap the benefits of this sturdy thermometer for years.

This 20-inch analog Greenco Compost Soil Thermometer is made from stainless steel and can take temperature readings in Celsius and Fahrenheit. Its dial contains three color indicators for you to gauge the optimum temperature range, yellow for ‘warm’, orange for ‘active’ and of course, red for ‘hot’.

A composting guide is included with this thermometer which breaks down the color code in greater detail; describing the different stages of composting until you reach the hot stage, where your compost pile will have reached peak efficiency and you can enjoy nutrient-rich soil for new plantings.

The 20-inch stem measures three-quarters of an inch in diameter, giving it some wear and tear resistance, and making it suitable for larger compost piles. There’s an upper-temperature limit here of just over 180 degrees Fahrenheit, and temperature readings take approximately 10 to 15 seconds to appear. Solid and dependable, this is a good all-rounder for your composting needs.

The Luster Leaf 1625 Digital Soil Thermometer is battery-powered and is scaled for Fahrenheit readings. And although not suitable for composting, it provides fast and accurate soil temperatures which are ideal for early season or transplanting. It has an upper-temperature reading of around 99 degrees Fahrenheit and can display moisture readings too.

Simply press the power button, insert the thermometer into the soil at a minimum depth of two to three inches, and check the recorded temperature after 60 seconds or so. Pressing the power button for a second time clears the display so that you can take further readings if needed. And if left on, it will switch itself off after a few minutes to preserve battery life.

Battery life is estimated to be good for up to around 1,000 soil readings, so there’s plenty of value for money here to enjoy. Readings are accurate too, if somewhat limited by the shorter 8-inch probe. That said, you can always dig down into your soil a little before insertion for a better reading if desired. The Luster Leaf is a quality digital thermometer, ideal for gauging germination temperatures and avoiding harmful transplant shock.

Offering high-precision performance, this Smart Choice Stainless Steel Soil Thermometer has a five-inch stem and a 1.5-inch glass-covered dial and is ideal for determining the best time to plant your seedlings or younger plants.

This analog thermometer has an upper-temperature limit of 220 degrees Fahrenheit and readings are accurate and reasonably fast. The glass-covered display dial is clear and easy to read and doesn’t suffer from fogging. The display shows a blue section (between 40 to 50 degrees Fahrenheit), and this is the recommended minimum temperature for germination.

Although this thermometer can be used for composting, its shorter probe limits its effectiveness in doing so. However, for indoor and outdoor potting and general planting, it’s more than up to the task and makes for a dependable gardening assistant.

Vee Gee’s 6-inch Stainless Steel Soil Thermometer is suitable for both soil and compost testing and has a temperature range of minus 40 degrees Fahrenheit to 160 degrees Fahrenheit. It has a large three-inch glass-covered display but doesn’t feature any color coding, unlike dedicated analog composting thermometers.

Its six-inch stem gives it a little more reach than some of its competition, although if you’re looking to cultivate larger piles of compost (for instance), you might want to opt for something that plunges deeper still. And some green-fingered readers may lament the lack of a Celsius scale here, too.

However, for fast and reliable Fahrenheit readings, it’s very hard to find fault here. This thermometer is well-made and capable of registering those top temperatures that many of its digital counterparts cannot.

The AcuRite 00661 Stainless Steel Thermometer has a seven-inch stem and comes with a protective sheath with a pocket clip attachment. Suitable for both indoor potting and outdoor gardening, this analog thermometer has a temperature range of zero to 220 degrees Fahrenheit, but with no Celsius readings.

Readings take around 30 seconds or so to register, and you can calibrate the thermometer manually to ensure its accuracy. With its higher temperature range, it’s also versatile enough to be suitable for composting; although again, the shorter probe can present some limitations for checking the temperature at the center of larger piles.

The dial itself has a weather-resistant construction, so it’s comfortable outdoors. That said, it isn’t waterproof, so caution is advised while using it in damp conditions. However, it’s well-made, accurate, and ideal for helping monitor soil temperatures for happy and healthy seeding.

Nothing says ‘gardening’ quite like worms, and this Urban Worm Soil Thermometer has been designed with these early bird favorites in mind. This 5-inch stainless steel analog thermometer is suitable both for gardening and worm composting (or vermicomposting).

Vermicomposting is the process of using worms to convert organic waste into useful fertilizer. To successfully use worms in this way, you need to keep them happy. The optimum temperature range for these worms to do their thing is between 55 and 90 degrees Fahrenheit; represented by the green zone depicted on this thermometer’s dial.

When the Urban Worm’s needle strays too far above or below this range, you know it’s time to move those little critters to a different area. With a temperature range of 20 to 120 degrees Fahrenheit, this soil thermometer wouldn’t suit conventional composting; but for everyday gardening and for helping keep worms in their happy place, this is a great little investment.