Jump Start Hot House | Heat Mat, 11x22 Tray, 72 Cells, 7.5 in Dome

What Comes in the Jump Start Hot House

Five things arrive together, which is the reason to take the kit rather than build one. A UL listed waterproof heat mat rated 17 watts on 120 volt, plus a watertight base tray measuring 11 x 22 in. Then a 72 cell seedling insert, a 7.5 in humidity dome and a tube of rooting gel. Instructions with growing tips come with it, and the mat itself carries printed guidance on the surface. That mat is deliberately gentle. It warms the root zone without running hot enough to scorch tender tissue, which is the failure mode of unregulated budget pads. The dome height is the part worth noticing. At seven and a half inches there is room for starts to get real height before they outgrow the lid.

Why Bottom Heat Beats Warm Air in Seed Starting Trays

Seeds and cuttings respond to root zone temperature, not to the air above them. Heating the room is slow, expensive and mostly warms the leaves, while a mat under the tray puts the energy exactly where germination happens. That is the whole argument for a heated propagator over a windowsill. Fill the cells with your own plug or medium, seat the insert in the tray, and close the dome to hold humidity while roots form. Vent the dome once you see growth, because trapped moisture that was helping germination starts encouraging damping off soon after. Lift the dome off entirely before the starts touch it. One honest limit is worth naming. There is no thermostat in this kit. The mat runs at fixed output, and a warm room can push the root zone higher than you want. If you are propagating through summer, a separate mat controller is worth adding.

Key Features

• 17 watt UL listed mat: Waterproof and gentle enough that it warms roots without scorching young tissue.
• Watertight 11 x 22 in tray: Holds runoff rather than letting it reach the mat or the bench underneath.
• 72 cell insert: Enough sites for a full propagation round from one tray.
• 7.5 in humidity dome: Taller than a standard lid, so starts gain height before they need potting on.
• Rooting gel included: The one consumable a cutting actually needs is already in the box.
• Printed guidance on the mat: Light, watering and planting notes sit where you will actually read them.

Technical Specifications