Whether you are just starting a garden for the first time or you are trying a new approach for an established garden, the best soil thermometers make a significant impact. They can play a role in the survival rate of direct seeds and seedling transplants.
Without checking your soil temperature before planting, your gardening project can literally wither away! Instead of wasting money on plants, buying a soil thermometer is the way to go.
Outdoor Happens is reader-supported. When you buy through links on our site, we may earn an affiliate commission. Click to learn more
Our best soil thermometer recommendation is the Greenco soil thermometer. It has a strong stainless steel probe, color-coded temperature ranges, and a lifetime warranty – all for just over $20!
Why Do You Need a Soil Thermometer?
Breaking it down into simple terms, a soil thermometer serves as a clock of sorts. It tells you when to put in plants or seeds.
Plants and vegetables tolerate various soil temperatures. Some crops thrive in warmer temperatures while others prefer colder temperatures.
Most soil thermometers generally include a coated probe or stem that can resist corrosion. You do need to perform some maintenance so that corrosion doesn’t sneak up and appear. If you plan on having an extensive garden full of fruits and vegetables, you need a soil thermometer to give you an idea of when to plant and not to plant.
How to Use a Soil Thermometer
It takes six easy steps to perform a temperature measurement.
- For starters, choose the proper depth to perform the measurement.
- Next, use a small device like a screwdriver to make a pilot hole. Because of this hole, the thermometer won’t be damaged if you force it into hard soil.
- Insert the thermometer into this hole and then follow the directions that come with the thermometer.
- If the sun is bright, provide a source of shade for the thermometer.
- Take a reading twice during the day, and then average out the two results.
- Lastly, check the reading and record it for future reference.
Our Best Soil Thermometer Review
Here is our best soil thermometer top 5! They’re all very affordable and of great quality, so you can’t go wrong, but our winner is durable, reliable, and comes with a life-time warranty.
1. Compost Soil Thermometer by Greenco
Made out of stainless steel, this soil thermometer is built to endure the outdoor elements. Whether it is very hot in the summer or the heavy rains of spring arrive, this thermometer is designed for long-lasting operation.
The lens and dial make up a durable device that can be easily read. The dial is 2 inches wide and has color-coded temperature ranges. The ranges extend from 40 to 180° Farenheit and 17.77 to 82.22° Celsius.
The lens is coated and sealed to prevent messy fogging and moisture.
The great thing about this thermometer is that it has a lifetime warranty, so if you are not satisfied with this you will get all of your money back! What a relief!
- DURABLE CONSTRUCTION: Solid 20 inch (508 mm) 0.2 inch (5mm) diameter stem; reinforced...
- CLEAR ACCURATE DIAL: Easy to read 2 inch wide dial with color-coded temperature ranges; 40...
- HIGH QUALITY LENS: High-quality and lightweight PC-coated lens, hermetically sealed to...
- COMPOSTING INSTRUCTIONS: Included to get you started
- LIFETIME WARRENTY, 100% MONEY BACK GARDENER SATISFACTION GUARANTEE: We are here 7 days a...
2. Vee Gee Scientific Dial Soil Thermometer
If you are looking for easy to read temperatures, this thermometer does the job with its large 3-inch glass-covered display. Temperature range is from -40 to 160° Farenheit.
This thermometer is very light at 6.3 ounces and has a thickness of only 0.25 inches. Made out of stainless steel, you will have no issues pushing this device into the soil as it won’t bend or flex.
If you choose to grow potatoes in a cold frame, for example, you can use this thermometer to make sure that the soil temperature doesn’t drop below 40 degrees. However, the only downside to this thermometer is that you can’t calibrate it or check it for accuracy.
- Large 3" Glass Covered Display
- Stainless Steel Stem for Durability, 6"
- Temp Range -40 to 160-Degree F
- Subdivisions 2-Degree F
- Calibration: Simple Adjustment Nut on Back
3. General Tools Analog Soil and Composting Dial Thermometer
This dial thermometer gives you a clear and concise reading of the soil temperature every time you check, which gives you a better idea of what kind of weather the soil is dealing with.
The probe of this thermometer is a 20-inch long shaft, which means you can stick this deep into the ground if you wish. The temperature range is from 0 to 220° Farenheit, which is displayed on an easy to read 2-inch wide dial.
It is also proven and tested for both indoor and outdoor gardens, and it works well taking ground and soil temperatures for composting and other agricultural activities.
- PROBE- 20-inch (508mm) long shaft
- TEMPERATURE RANGE- Measures 0° to 220°F (-18° to 104°C)
- EASY TO READ: 2-inch (51mm) wide dial with a clear glass lens
- RUGGED DESIGN- Rustproof and long-lasting stainless steel probe
- VERSATILE- Ideal for taking ground and soil temperature for composting, gardening and...
4. AcuRite Stainless Steel Soil Thermometer
This may be one of the shorter thermometers on this list, but AcuRite created a hardy and reliable device. It was constructed to be specifically weather-resistant, as it is designed to be used both indoors and outdoors.
Having a 7-inch long stem, this thermometer must be placed at least 3.5 inches deep into the soil before it will give you a proper temperature reading.
However, this device only reads temperatures. You would have to buy a separate device that also measures other functions like pH levels and moisture. Other details you will appreciate are a protective sheath with a pocket clip, and a limited 1-year warranty.
- Monitor soil temperature for healthy seeding, planting and gardening
- Perfect for indoor potting or outdoor gardening
- Measures temperatures from 0 to 220 degrees Fahrenheit
- 7-inch easy-clean stainless steel stem
- Includes protective sheath with pocket clip
5. Luster Leaf Soil Thermometer, 8 Inch
If you want to stick with a classic Old School thermometer design, this guy will make you happy.
This thermometer is encased in corrosion-free aluminum, meaning it can endure all sorts of weather conditions. This best soil thermometer has a 6-inch long stem which provides plenty of length to obtain proper temperature readings.
It is very lightweight at 1.44 ounces and it is very cheap in price.
However, you will need to practice a little patience with this device. This thermometer needs to set in place for at least 10 minutes before you pull it out for a reading. You can use this classic thermometer during the spring season to detect when the soil is warm enough to plant your favorite veggies.
- Great tool for determining soil temp for early season and transplanting
- Classic thermometer design with durable casing
- Guidelines for germination and transplant temperatures included
- 6” probe provides plenty of length to obtain proper readings
- Specifically designed and calibrated for use in soil only
- From Rapitest – The Leaders in Soil Testing
Best Soil Thermometer Buyer’s Guide
While it is nowhere near as difficult as trigonometry, the process of choosing a soil thermometer does take some careful planning.
Keep in mind that not just any thermometer will work for your soil. It depends on what types of plants you have in your garden and what you are doing to affect the soil’s temperature, for starters. Here are some questions to ponder before buying a soil thermometer.
How Do I Measure Soil Temperature?
Right away I can tell you that you won’t get a proper soil temperature reading if you barely stick a thermometer into the ground.
For new seeds and plants, take your measurement at the recommended planting depth. Check at least 5 to 6 inches deep if you have a mixed garden. Follow the specific instructions that are provided by your thermometer package.
Under bright sunlight, keep the thermometer shaded by your hand (or some other object) to keep the temperature reading accurate.
What Time of Day Should You Measure Soil Temperature?
I recommend taking multiple measurements in the morning and the late afternoon. Once you do this, average the two numbers.
If you are attempting to seed a lawn, measure the temperatures of all four sides of your home. Some areas tend to warm up quicker than others.
How Warm Should the Soil Be to Plant Tomatoes?
The ideal soil temperature for tomatoes should be at least 70° Fahrenheit or warmer. This same temperature range can be applied to other vegetables like melons, peppers, cucumbers, squash, and corn.
How Warm Should the Soil Be to Plant Lettuce?
On the flip side, vegetables like lettuce are hardier.
Along with peas, spinach and kale, lettuce can be planted in soil temperatures of at least 40° Fahrenheit or warmer.
What Degrees Should the Thermometer Read Before Placing It Into the Soil?
It can read any temperature. Thermometers read the temperatures of their environment, and soil thermometers will always read the temperature of the air surrounding it.
How Deep Should a Thermometer Be In the Soil to Be Accurate?
The lower part of the best soil thermometer will record the temperature.
This means you should think about the kind of planting you are doing. If you are into seeds, insert the thermometer shallowly into the soil.
You are aiming to measure the temperature of the root area of the plant, so make sure you insert the thermometer to the depth your seeds will be in the ground.
Which Soil Thermometers Are Better? Classic or Modern?
It depends on the gardening project you have.
If you are sticking with a basic vegetable garden that has only a few crops in a single row, the thermometers with the classic designs will work just fine.
If you are aiming to be more technical and diverse with your garden and you want to be an around-the-clock vegetable farmer, consider looking at the modern designs first.
However, there is no wrong answer here. From my experiences growing crops, I would most likely go with the classic design thermometers.
The Variables of Checking Soil Temperature
There are many variables that come from a basic soil test. Things pinpointed in these tests include the levels of pH and macronutrients like nitrogen, phosphorus, and potassium. Let’s not forget about the amount of organic matter as well.
Basic soil tests only give you information on general soil characteristics. Pollutants, pesticides, or other toxic compounds are not detected by these tests.
Checking soil temperature doesn’t require you to plant all your fruits and vegetables in one particular season if there is no need to. As mentioned before, some crops thrive in colder temperatures and others do well in the warmth.
Your Best Soil Thermometer
After reviewing all of the listed soil thermometers, which one is the best for you to buy?
The answer is simple. Any of them!
As you have noticed, all of these thermometers are reasonably cheap in price and they all do their jobs efficiently enough for any kind of vegetable garden. You shouldn’t be spending any more than a maximum of $30 for a soil thermometer anyway.
One suggestion I have for gardeners who aspire to grow fruits and vegetables is to stay vigilant throughout each season. Watch how the weather changes before you start using a soil thermometer. Depending on where you live, temperatures can swing from one extreme to the other, and sometimes you just gotta go with the flow.
I wish you guys the best in your soil tests!
Last update on 2021-08-02 / Affiliate links / Images from Amazon Product Advertising API