How to use coir pellets without drowning the seeds
Updated: 21 October 2026
You have a sleeve of hard discs and a tray, and you want to know how to use coir pellets before the compost turns to soup. The aim is a plug that is moist rather than dripping, a seed at the depth on the packet, and a sleeve you can slit if roots cannot leave. Prices and pack choice sit on the [seed starting pellets comparison](/hub/herb-seeds/seed-starting-pellets). Peter F. wrote this from amazon.co.uk review patterns read on 19 October 2026 and public sowing advice. A qualifying purchase through our links can earn a commission at no extra cost to you.
You have a sleeve of hard discs and a tray, and you want to know how to use coir pellets before the compost turns to soup.
You have a sleeve of hard discs and a tray, and you want to know how to use coir pellets before the compost turns to soup. The aim is a plug that is moist rather than dripping, a seed at the depth on the packet, and a sleeve you can slit if roots cannot leave. Prices and pack choice sit on the seed starting pellets comparison. Peter F. wrote this from amazon.co.uk review patterns read on 19 October 2026 and public sowing advice. A qualifying purchase through our links can earn a commission at no extra cost to you.
Our top picks
| Badge | Product | Wrap | Nutrients stated | Dry diameter | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  e-pots e-pots (36 mm, pack of 100) | FSC paper | Not stated in this listing's bullets | 36 mm | 9.1 | about £16.99 | View offer |
| Alternative |  GROWEASY GROWEASY (36 mm, pack of 24) | Paper | Listing says seedlings get the nutrients they need | 36 mm | 8.2 | about £7.99 | View offer |
| Best value |  Lawei Lawei (30 mm, pack of 200) | Not named in the listing; UK reviews mention netting | Moisture, oxygen and pH claimed; no feed analysis | 30 mm | 7.9 | about £15.99 | View offer |
Soak and drain
Stand the dry discs in a watertight tray, spaced so they can swell without climbing on each other. Add lukewarm water. Do not copy another brand's five-to-six-times claim onto GROWEASY, e-pots or Lawei.
Stop when the disc is dark, damp and has stopped growing. Tip the spare water away. If water streams out when you press the plug, it is still too wet. The RHS says wet compost is cold, and coir can hold a lot of water, which slows germination. A Women's Environmental Network sheet says to soak from below and then water only when the plug is quite dry, because overwatering encourages mould.
Sow and cover
Sow at the depth on your seed packet, in the dimple on top of the plug. A common charity sheet says larger seed goes down to about twice its own size, and very small seed is pressed onto the surface. One or two seeds is enough. If both germinate, snip the weaker seedling so you do not tear the coir.
Cover the tray if the packet asks for humidity, and air it each day. Water again only when the plug lightens. Herb months are on seed pellets for herbs. If the disc you soaked is still a flat coin, do not sow into it.
When something goes wrong
Weak swell is common enough to plan for. On the e-pots 100-pack, one UK review said some pellets only reached about 1 cm and felt hard, while others became solid cylinders or fell apart. Set aside any disc that stays hard. A poor swell on the Mr Fothergill's refill belongs to that refill, not to Lawei or GROWEASY.
A GROWEASY buyer said pellets fell apart in the hands. An e-pots review said the wrap sits around the sides only, so coir washes out. Surface mould is a water problem unless the unused bag arrives mouldy. If every disc arrives mouldy, that is a return.
Planting the plug on
Move the plant on when it has a few true leaves and roots show at the side or base. The RHS basil method uses a 7.5 cm pot of peat-free compost at that stage. Do not leave a herb in a 30 mm plug all summer. If the e-pots 20-pack is the one you bought, the listing says the coir contains no nutrients, so the seedling needs compost or a weak feed after potting on. Do not assume every disc already contains feed.
A GOTVUGE review said pea roots could not get through the mesh. If roots are circling, slit the sleeve even when the bullet said biodegradable. EN 13432, where a maker cites it, is industrial composting, not a border. What a biodegradable net may mean is on coir pellets vs peat pellets. If someone has swallowed a quantity of the medium, use NHS 111.
Common questions
Should I use warm or cold water?
Lukewarm water is the sensible default for a kitchen tray. Jiffy says hot or cold water is acceptable for its 7C pellet, which is not a measurement of every disc in this set. Very cold water slows the swell and leaves the plug cold, which the RHS links to poor germination in wet compost. If the disc has not moved after several minutes, add a little more warm water and wait again.
How long do I soak coir pellets?
There is no single time that fits every brand in this comparison. Other sellers often say a few minutes for their own 30 mm or 35 mm pellets, and one e-pots reviewer said the 100-pack expanded almost immediately. Another said some discs barely swelled. Wait until that disc has stopped growing, then drain it.
How many seeds go in one pellet?
One seed is enough for anything you would rather not thin, and two is a spare if germination is patchy. Snip the extra seedling instead of pulling it. A pellet the size of these 30 mm and 36 mm discs is not a module for a pinch of seed. Very small seed stays on the surface. Larger seed goes to about the depth on the packet.
What if the surface goes mouldy?
Ease off the water, give the tray some air, and remove a fuzzy patch if the seedling is still sound. One GROWEASY review reported surface mould after the pellets were watered. This page does not identify the mould. If the unused discs arrive mouldy in the bag, contact the seller about a return rather than sowing them.
Do I cut the net off?
Cut or peel it if roots are not passing through, or if the sleeve is tight after swelling. A GOTVUGE review described pea roots blocked by the mesh. A Lawei review said the netting could hinder roots and did not biodegrade well. Some listings tell you to plant the whole plug. Sarah Raven says to slip a Jiffy coir net off. Not every net is PLA, and EN 13432 is industrial composting where it applies.
When do I pot on?
Pot on when the plant has several true leaves and you can see roots at the plug, into a small pot of peat-free compost. For basil the RHS uses a 7.5 cm pot at that stage. Harden tender herbs before they go outside, and do not put basil out while frost is still likely.
Related pages
Sources
Public UK sources named below. amazon.co.uk prices, stars and review counts on these seven listings were read on 19 October 2026. Page updated 21 October 2026.
- GOV.UK: sale of horticultural peat to be banned, 27 August 2022 (retrieved 19 October 2026)
- RHS: retail peat-free note, 19 October 2025 (retrieved 19 October 2026)
- DEP2026-0072, letter of 29 January 2026 (retrieved 19 October 2026)
- RHS: peat-free seed sowing (retrieved 19 October 2026)
- RHS: coir questions answered (retrieved 19 October 2026)
- RHS: grow your own basil (retrieved 19 October 2026)
- Consumer Rights Act 2015, section 11 (retrieved 19 October 2026)
- CAP Code 11.1, environmental claims (retrieved 19 October 2026)