Grow Gadgets Seedling Heat Mat | Waterproof Propagator Mat, 3 Sizes

The Grow Gadgets heated mat is a waterproof heat mat for seedlings that gently warms seed trays and propagators up to 20°C above room temperature. It comes in three sizes, from a single-tray 18W mat to a 105W shelf-length mat.

February on the kitchen windowsill: chilli and tomato seeds sown, the propagator lid on, and a chilly draught from the glass. Slide this slim mat underneath, plug it in, and the compost stays snug and warm, so the first green loops appear days sooner.

A heat mat for seedlings that brings spring forward

Many seeds need warm soil, not just warm air, to wake up. Gentle bottom heat makes germination faster and more reliable, especially for chillies, peppers, tomatoes and basil. It means fewer empty cells and more little plants to share.

It turns a winter weekend into a growing adventure. Children can sow, label and check each morning, and with warmth underneath they won’t have to wait long for the first shoots.

What your heat mat helps with

• Faster germination of chillies, peppers and tomatoes
• Rooting herb and houseplant cuttings
• Early sowings on a cool windowsill or shelf
• Keeping propagators warm through chilly nights
• Starting seeds in a shed, greenhouse or garden room

Gentle warmth from below, right where roots need it

• Up to 20°C warmer. Warms the root zone well above room temperature for quick, even germination.
• Three sizes. From one standard seed tray to a whole shelf (see table).
• Fully sealed and waterproof. Drips from watering and drainage are no problem.
• Slim and simple. Lay it under a propagator, plug in at the mains and you’re done.
• Cheap to run. The smallest size is rated at just 18 watts.

Seedling heat mats: your questions answered

Do seedlings need a heat mat?
Not all, but warmth-loving seeds such as chillies, peppers, tomatoes and basil germinate much faster and more evenly with gentle bottom heat.

What temperature should I germinate seeds at?
Many vegetable and herb seeds germinate well at around 20 to 25°C; chillies and peppers prefer the warmer end. Check your seed packet.

Do I need a thermostat?
The mat works on its own. For precise control, Grow Gadgets make a matching heated mat thermostat (sold separately).

Should I move seedlings off the mat after germination?
Usually, yes. Once most seeds are up, move the tray off the mat or turn it down so seedlings grow sturdy rather than leggy.

The details

Sizes and measurements

In the box

1 × Grow Gadgets heated propagation mat in your chosen size.

Warm roots, quick shoots, and spring arriving early on your windowsill.