Jiffy-7 Peat Pellets 41mm — Professional Seed Starting & Propagation Medium (1000 Box)
Best for: Commercial growers, propagators, and anyone serious about seed germination and cutting rooting without the fuss
Our thoughts
These are the industry standard for a reason. Pre-fertilised, pre-dibbled, and expand to the right size first time — they're what commercial operations use because they work reliably. If you're starting seeds or rooting cuttings at any scale, worth having a box on hand.
Jiffy-7 Peat Pellets are compressed peat discs wrapped in fine biodegradable netting, designed to expand when hydrated and become both your growing medium and container in one. At 41mm wet (38mm dry), they're the industry-standard size for commercial propagation, pre-fertilised and pre-dibbled to cut your setup time to nothing. Drop in a seed or cutting, add water, and they do the job properly — no mixing, no guessing, no waste.
How it compares
Peat pellets sit in the middle ground between convenience and cost.
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vs Rockwool: Peat's more affordable and pre-fertilised; rockwool's pathogen-free but needs separate nutrient management
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vs Coco coir: Similar cost, but peat's proven track record is longer and it's what most UK growers default to
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vs Soil blocks: Less labour-intensive; pellets expand automatically, no hand-blocking required
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vs Seed trays: Individual pellets mean air pruning and easier transplanting; trays require manual fill and cause more transplant shock
Usage guidance
Hydrating the pellets
Place pellets in a propagator tray or saucer, hole side up. Add tepid tap water to the base and let them expand naturally over 20 minutes or so. They'll swell to roughly 7 times their original size.
Sowing seeds
Once hydrated, make a small hole (roughly 5mm) in the top and drop your seed in gently. Cover lightly and keep moisture consistent but not waterlogged. The pre-dibbled hole helps — no need to mess about making your own.
Rooting cuttings
Dip the base of your cutting in rooting hormone (Clonex works well), then insert it about two-thirds of the way into the pellet using a cocktail stick to pre-hole if needed. The moisture in the peat supports rooting development immediately.
Transplanting
The whole pellet goes straight into soil or into a larger pot — the biodegradable netting breaks down naturally, so roots transition without disruption. Compatible with Grodan Transplanting Cubes (41mm large-hole size) if you're working a modular system.
Technical specifications
- Dry diameter: 38mm
- Wet/expanded diameter: 41mm
- Height: Approximately 42mm when hydrated
- Expansion ratio: Up to 7 times original size
- Base material: Weed-free Canadian Sphagnum peat
- pH: 5.3 (no pH adjustment needed with tap water)
- Pre-fertilisation: Yes — lime and low-ammonia fertiliser included
- Pre-dibbled: Yes — ready for seed or cutting insertion
- Netting: Fine biodegradable mesh, optimised for air and water exchange
- Expansion time: Approximately 20 minutes
- Packaging: 1000 pellets per box
Who this is for
- Commercial propagators and nurseries working at scale
- Growers starting seeds indoors on any budget
- Anyone rooting cuttings and wanting reliable, consistent results
- Operations already using Grodan systems or standard propagation trays
- Growers who value speed and minimal labour in the propagation stage
Our take
Jiffy-7 has been the commercial standard for decades because it removes friction from propagation. Pre-fertilised means you're not dosing young seedlings with full-strength nutrients. Pre-dibbled means you're not faffing about with a stick every time. The peat holds moisture in the sweet spot — not soggy, not dry.
At 1000 per box, the cost per pellet is low enough that you can stock without worry. Good time to buy while clearance stock lasts. Worth picking up if you're serious about propagation.
