Ferry-Morse Heat Mat - 10in x 20in - 17.5 Watt

Bottom Heat Seedling Mat for Faster, More Even Germination, 10in x 20in

Cold soil is one of the most common reasons seeds germinate slowly or unevenly indoors, since most vegetable and flower seeds germinate fastest within a fairly narrow root-zone temperature range that an unheated windowsill or basement rarely reaches on its own. The Ferry-Morse Heat Mat warms the tray from below to close that gap.

At 17.5 watts, the mat delivers steady, low-level warmth sized for a standard 11in x 22in tray, without the temperature swings of relying on ambient room heat alone.

Key Features & Benefits

• 17.5-watt bottom heat element — warms the root zone evenly under a standard seed-starting tray.
• Sized for standard 11in x 22in trays — fits under the tray size used across most seed-starting kits.
• Indoor use only — designed for controlled environments like windowsills, shelves, and grow tents.
• Consistent, low-level warmth — raises root-zone temperature without the swings of ambient room heat.

Who Should Use This

This fits home gardeners and hobbyist growers starting seeds indoors in a room that runs cool, especially in early spring before household heating keeps a consistent temperature, or in a basement or garage grow space.

About Ferry-Morse

Ferry-Morse has sold seeds and seed-starting supplies since 1856, and the brand now operates under Green Garden Products alongside Jiffy. The heat mat line extends that seed-starting focus into equipment, addressing the temperature half of the germination equation.

Frequently Asked Questions

How do I use a seedling heat mat

Set the mat on a flat, water-resistant surface, place your seed tray directly on top, and plug it in. Leave it running until seeds germinate, then move seedlings off the mat once they've sprouted to avoid overheating the root zone.

When should I turn the heat mat off

Turn it off once most seeds in the tray have germinated, since actively growing seedlings generally don't need the same bottom heat that speeds germination. Leaving it on too long can dry out growing medium faster than expected.

Can I use this mat outdoors or in an unheated greenhouse

No, this mat is built for indoor use only. Using it in a damp, unheated outdoor space isn't a supported use and increases the risk of electrical issues.

Does the mat work with any 11x22 tray

Yes, the mat is sized to the standard 11in x 22in tray footprint used across most seed-starting trays and greenhouse kits. It works under both Ferry-Morse and Jiffy trays alike.