Jiffy Gro-Dome Humidity Dome - 11in x 22in - Greenhouse Effect for Seed Germination

Standalone Humidity Dome for Seed Germination, 11in x 22in

A tray alone doesn't hold in the warmth and moisture seeds need to germinate reliably, and buying a whole new greenhouse kit just for the cover wastes money on a tray you may already have. The Jiffy Gro-Dome is sold on its own, sized to fit any standard 11in x 22in plant tray.

Because it's sold separately, growers can replace a lost or cracked dome, add a cover to a tray that didn't come with one, or keep a spare on hand without buying an entire new kit.

Key Features & Benefits

• Fits standard 11in x 22in trays — compatible with most seed-starting trays already on hand.
• Clear dome construction — lets light through while trapping warmth and humidity above the tray.
• Creates a greenhouse effect — raises humidity and temperature around seeds for more reliable germination.
• Sold separately from a tray — replace a lost or cracked dome without buying a whole new kit.

Who Should Use This

This fits growers who already own an 11in x 22in seed-starting tray and need a replacement or spare humidity dome, or anyone building a custom seed-starting setup from separate parts.

About Jiffy

Jiffy, under Green Garden Products, sells its dome, tray, and pellet components separately as well as in complete kits, so growers can replace or mix and match individual pieces instead of buying a full system every time.

Frequently Asked Questions

How does a humidity dome help seeds germinate

The dome traps the warmth and moisture rising off a watered tray, creating a small greenhouse effect that keeps humidity high around the soil surface. That consistent moisture is what most seeds need to germinate evenly.

When should the dome be removed

Remove the dome once the first seedlings emerge, or vent it for a day or two if only some seeds have sprouted. Leaving it on too long after germination raises the risk of mold and damping-off.

Will this dome fit any tray I already own

It's built for the standard 11in x 22in tray footprint used across most seed-starting trays. It should fit any tray built to that common size, regardless of brand.

Can I use this dome without a tray from Jiffy

Yes, the dome works with any 11in x 22in tray regardless of brand. It's sized to the standard footprint rather than a proprietary tray design.