Propagation Media

Propagation media are the small plugs and cubes a seed or cutting starts life in. The job is narrow: hold the stem upright, stay damp without going waterlogged, and let the new roots grow out of it without being disturbed when you pot on.

The main types

The practical rule: start in something compatible with where the plant is going. A rockwool plug into soil works but never quite integrates; a coco plug into coco disappears seamlessly.

Getting it right

• Damp, not wet. The commonest failure by a mile. A plug that is soaked has no air in it and the stem rots before roots form. Squeeze out the excess and keep it just moist.
• Condition rockwool first. New rockwool is alkaline and needs a 24-hour soak at around pH 5.5.
• Bottom heat. 21-24°C at the tray. More important than anything you can buy in a bottle.
• Do not feed. A cutting has no roots and a seed carries its own food. Plain water or a very dilute first feed – see propagation nutrients.

Pot on at the right moment

When roots are visible at the sides and base of the plug, not before and not long after. Left too long, roots circle and the plant checks when you finally move it.

What we stock

Grodan rockwool plugs, Root Riot cubes, jiffy pellets, coco plugs and propagation trays. Pair with propagators, propagation lights and a heat mat. See the whole range on growing media.

Why buy propagation media from The Hydro Bros?

We are a hydroponics shop in Croydon and we root cuttings every week, so we stock what actually works rather than what has the best packaging. Discreet UK and European delivery, and excellent customer reviews on Trustpilot.