Any gardener can start growing plants from seed with a little help from a plant heating mat. These sealed mats sit directly beneath trays of seedlings to help maintain consistent warm temperatures during the germination process. They help seedlings sprout in cooler climates or in variable weather conditions.
The size, materials and accessories all play a part in finding the best mat for your seedlings. If you’re looking for a durable and high-performing heating pad for your seedlings, the Hydrofarm Plant Heating Pad is the best one for home gardeners.
When searching for a plant heating mat, consider the size of the mat, the durability of the materials and whether you need a thermostat. Plant heating mats come in varying sizes and durability levels. Evaluating which mat is best for your needs depends on where you plan to grow your seedlings and what types of plants you’re germinating.
Most plant heating mats measure between 10 inches wide by 20 inches long and 20 inches wide by 48 inches long. Depending on the size of the mat, it can support up to four standard seedling trays, which measure 10 inches by 20 inches. Use those measurements to calculate how many trays you can fit on your mat and how many mats you need.
If you’re using a custom seedling tray, you’ll need to measure your specific containers and calculate what size mat you’ll need.
As you choose the right size mat, be sure to think about the mat’s location. Where you place it determines how large it can be. You can place most smaller mats on tables, countertops, window sills, potting benches or anywhere that gets enough light. Measure the space before choosing a mat, keeping in mind that larger mats need more surface area than smaller mats.
One special feature of plant heating mats is that they must be water-resistant. Since you spritz and water your seedlings regularly, a durable, water-resistant mat is the best way to keep your seedlings safe and keep your workspace clean. You can also find mats that are entirely waterproof and weatherproof, which is useful if you plan to place your seedlings in more exposed areas like a porch or a potting shed.
Additional features in your mat can help you level up your home gardening practice. A digital thermostat, probe, unit settings and auto shut-off mode all enhance your home garden setup and give you more control over the germination process.
Some plant mats come with a digital thermostat that let you set a specific temperature. Heating mats without a thermostat usually heat between 70 degrees and 80 degrees. That temperature range is useful for some seedlings but not for all.
If you plan to grow plants with more specific needs or want more control over the germination process, you can set your thermostat to between 40 degrees and 100 degrees. You likely won’t need to reach these extreme temperatures, but thermostats offer more flexibility for growing plant species that need custom settings.
Some plant heating mats offer an external probe or heat sensor that you can stick in the soil to gather the exact temperature of your seedlings. This gives you more insight without adding a full thermostat to the mat. A probe or sensor helps you understand the mat’s heat output for more sensitive plants that need more precise temperatures.
Fahrenheit is the standard unit of temperature in the United States and you should find a mat that displays the temperature in that unit. If you’d rather use Celsius, look for a mat that offers multiple units of measurement so you can switch to your preferred unit.
For germinating your seedlings, you’ll want to keep your mat on at all times, day and night. However, in the case of emergency outages, surges or overheating, an auto-shutoff mode is useful. It offers an extra layer of safety if the unit malfunctions and keeps your seeds from overheating.
You can expect to spend between $10 -$90 on a mat, with most midrange options falling around $30.
A. If you want to heat your seedlings, yes. Different types of household heating mats are safe for their specific use cases. Pet heating mats are suitable for cats and dogs to sleep on. Medical heating pads are built for use against your body’s muscles and joints. Each of these pads features temperature settings specific to those purposes. Plant heating mats need to be more delicate and balanced in their heat settings and distribution, as well as waterproof or water-resistant to protect against spills.
A. Yes. Seedlings sprout best when their environment is consistent, including their watering schedule and soil temperature. Be sure to leave the mat on at night since that’s when temperature drops can disturb the germination process. Once germination starts, remove the heating pad immediately as the heat can overstimulate delicate roots. These mats have very low wattage, so energy consumption isn’t a concern.
A. If you water them as directed and give them the appropriate amount of sunlight, some of your seeds should sprout. However, seedlings are delicate and finicky. They are vulnerable in the first days of growth and have a much better chance of survival when they are in stable conditions. Plant heating mats mimic the warming soil of spring, giving seeds the signal to germinate. Mats also drastically speed up germination and allow you to start growing seedlings early if you live in a colder climate.
What you need to know: This high-quality plant heating mat is built to last for the avid home gardener.
What you’ll love: The heat distributes evenly throughout the mat and maintains its temperature. The mat lays flat and is made with durable materials. It germinates seeds in about half the time. The power cord measures 6 feet long.
What you should consider: This mat is more expensive than others on the market.
Where to buy: Sold by Amazon
What you need to know: This mat offers great results at an affordable price for gardeners at any level of experience.
What you’ll love: The mat germinates most seeds within a week. The five-layer structure distributes heat evenly and the material is water and weather-resistant. It comes in a reusable storage bag and temperature control.
What you should consider: Some customers have noticed the mat does not always heat evenly.
Where to buy: Sold by Amazon
What you need to know: This high-performing plant heat mat is perfect for the busy gardener.
What you’ll love: You can set the temperature with the digital thermostat and walk away, knowing the mat will deliver the exact temperature given and distribute heat evenly. Regulate the temperature as needed and choose between Celsius and Fahrenheit. Expect your plants to sprout within a week.
What you should consider: The LED lights in the thermostat may not last long, but metrics are still visible without the lights.
Where to buy: Sold by Amazon
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Katy Palmer writes for BestReviews. BestReviews has helped millions of consumers simplify their purchasing decisions, saving them time and money.