Jiffy Windowsill Greenhouse with SUPERthrive - 20-Cell

Compact Windowsill Greenhouse Kit with SUPERthrive, 20-Cell

A windowsill doesn't offer much surface area, but a kit sized to fit one can still start a respectable batch of seedlings without spilling onto the rest of the sill. Jiffy's 20-cell Windowsill Greenhouse includes a bonus SUPERthrive sample to give young roots a head start in that limited space.

The 20-cell count strikes a middle ground for windowsill growing, more capacity than a minimal starter kit while still fitting a typical sill without crowding out other plants.

Key Features & Benefits

• 20 biodegradable peat pellets — compressed peat that expands with water into individual growing cells.
• Compact windowsill footprint — sized to fit on any windowsill without crowding out other plants.
• Watertight tray and humidity dome — included in the kit for a complete, ready-to-use setup.
• Bonus SUPERthrive sample — a root-development boost included with this kit.

Who Should Use This

This fits home gardeners with limited windowsill space who want a complete, ready-to-use kit for a modest batch of herb, flower, or vegetable seedlings.

About Jiffy

Jiffy sizes its Windowsill Greenhouse line specifically for compact spaces, applying the same expand-with-water pellet system used across its larger kits at a scale that fits a single windowsill ledge. Green Garden Products, Jiffy's parent company, carries this alongside larger-format kits for growers who need more room.

Frequently Asked Questions

How do I use this windowsill kit

Set the pellets into the tray, add warm water, and let them fully expand before sowing seeds into the top of each pellet. Replace the humidity dome until seedlings emerge, then remove it gradually.

When should I apply the SUPERthrive sample

Apply it during your first watering after sowing, following the dilution instructions on the sample packet, or wait until seedlings show their first true leaves. It's a supplement, not a substitute for regular watering.

Will 20 cells fit on a standard windowsill

Yes, this kit is sized specifically for a windowsill ledge, smaller than Jiffy's larger greenhouse kits. It fits where a full-size tray wouldn't.

Can I transplant the pellet directly into soil

Yes, the pellet's netting breaks down naturally once it's in the ground. The seedling and its root ball transplant together, with nothing to remove or disturb.