Best seedling heat mats with thermostat
Heat mats differ in size, in watts and in whether a thermostat comes with them. Several listings leave key numbers out.
Not tested. These picks come from the specifications each maker publishes, read on the date below. We have not used the products. See how we pick products. Prices and stock change, so check the current listing before you buy.
| Mat | Sizes | Controller | Stated numbers |
|---|---|---|---|
| VIVOSUN seedling heat mat and digital thermostat combo | 10 x 20.75, 20 x 20.75 and 48 x 20.75 in | Digital thermostat with probe, 68 to 108 degrees F | Mat about 68 to 86 degrees F. MET standard. 45 W is given for the 20 x 20.75 in size. |
| Hydrofarm Jump Start seedling heat mat | 20 x 20 in (45 W) and 48 x 20 in (107 W) listed | The page does not state that one is included | Waterproof. Warms the root area 10 to 20 degrees F over ambient. |
| SUNCORE (AC Infinity) models | 3 x 20, 10 x 20.75, 20 x 20.75, 48 x 20.75 in and a dual 10 x 20.75 set | Varies by model: none, heat controller or digital controller. The H series controller is described as settable from 32 to 122 degrees F. | AC Infinity says quality mats raise soil temperature roughly 10 to 20 degrees F above ambient. |
| Johnny's Selected Seeds heat mat | 20.75 x 20.75 in (and a 20.75 x 48 in listing) | The page text we could read does not say | Described as improving germination for heat-loving crops. Watts and price were not in the text we could read. |
How to pick
- Size. A 10 x 20.75 inch mat suits one 1020 tray. Larger mats cover several.
- Controller. AC Infinity says a thermostat gives more control, lets you monitor soil temperature and reduces overheating risk. Utah State says to unplug a mat that gets too warm.
- Range. Make sure the range covers what your crop needs. Check your seed packet.
- Safety marks and warranty. VIVOSUN's own page gives conflicting warranty wording, so read the current terms for any mat.
Where to buy
- VIVOSUN combo (manufacturer page)
- Hydrofarm Jump Start 20 x 20 in (manufacturer page)
- SUNCORE (AC Infinity) guide (manufacturer page)
On Amazon
These are links to Amazon product pages, not affiliate links. We chose them from Amazon search results by title and customer rating. We have not checked their specifications line by line, so read the current listing before you buy. Prices change, so none are shown here.
- BN-LINK 10 x 20.75 in seedling heat mat with thermostat controller combo set. Mat and controller together.
- BN-LINK 10 x 20.75 in seedling heat mat. Sold without a controller, so you would need a separate thermostat.
- Hon&Guan 10 x 20.75 in seedling heat mat with digital thermostat combo set. Fewer customer ratings than the BN-LINK listings.
More in the heat mat and thermostat guide.
Sources
- VIVOSUN: 10 x 20.75 in seedling heat mat and digital thermostat combo, manufacturer page
- Hydrofarm: Jump Start seedling heat mat, 20 x 20 in, 45 W (MT10008)
- AC Infinity: What is a seedling heat mat?
- Utah State University Extension: Starting vegetable seeds indoors, seeding culture and transplanting (2025)
- Johnny's Selected Seeds: Seedling heat mat, 20.75 x 20.75 in