Seed + Cloning Plugs

Clone plugs hold air and water around a fresh cutting or seed, so new roots form in one cube and transplant without disturbance. Soil and coco growers lean on peat and coco plugs. Rockwool rooms start in Grodan A-OK, and aeroponic cloners use neoprene collars.

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Seed + Cloning Plugs

Clone Plugs and Seed Starter Plugs

Clone plugs are small, pre-formed cubes of peat, coco, stone wool or foam that hold a cutting or seed until roots break through the sides. This collection covers Rapid Rooter, Root Riot, OrganiPlug, Grodan, Oasis and Botanicare plugs, plus EZ-Clone collars. Not sure which fits your grow? Start with our guide to the best cloning cubes....

Clone plugs infographic: peat and coco plugs, stone wool and foam cubes, neoprene collars, sizes and soak steps

Plugs sit inside the 50-cell inserts and flats on our trays and humidity domes page. Both belong to the wider propagation supplies range.

Types of Seed and Cloning Plugs

Peat and Coco Plugs

General Hydroponics Rapid Rooter plugs are 1.5 inch rounds of sphagnum peat and composted bark. Root Riot cubes are composted peat and arrive pre-moistened. OrganiPlug uses OMRI listed coco, peat and biochar with trichoderma. Botanicare CocoPro Plugs blend coco with mineral wool. Pick these for soil, coco or organic grows.

Stone Wool and Foam Cubes

Grodan A-OK plugs come 98 to a sheet and fit a 10 x 20 flat. PRO and Macro Plugs scale up for commercial benches. Oasis Rootcubes are a low-density foam, often used for hydroponic lettuce, herbs and tomatoes. Both press into larger rockwool blocks.

Neoprene Cloning Collars

EZ-Clone 2 inch hard inserts come 35 to a pack, enough for a 32-site unit from our cloning machines range. Hard collars hold woody cuttings upright.

How Growers Use Rooting Plugs

Set a cutting only deep enough to stand on its own. Mist it, then cover the tray to hold humidity. Keep watering light while roots are inside the plug. When roots show at the sides, transplant the whole cube into the next block or pot.

Frequently Asked Questions

What are plant plugs made of?

Most hydroponic plant plugs are peat, coco, stone wool or foam, sometimes bound with a plant-based binder. Rapid Rooter mixes sphagnum peat and composted bark. Grodan A-OK is stone wool spun from molten rock. Oasis Rootcubes are a high-drainage foam, and OrganiPlug adds biochar to coco and peat.

What is the difference between Rapid Rooter and Root Riot?

Both are peat-based seedling plugs with a pre-formed hole, and both come in a 50-cell tray. Rapid Rooter adds composted bark and a foam binder, and General Hydroponics advises a soak before use. Root Riot is fine milled composted peat that comes pre-moistened. Its tray holds no rooting gel, despite some product names.

How long to soak Rapid Rooters?

General Hydroponics soaks Rapid Rooter plugs for about two hours in pH balanced water near 6.0. Squeeze each one gently four or five times to push the air out. They are chemically neutral, so unlike rockwool there is no buffering step. Then set the seed or cutting in the hole.

Are Rapid Rooters better than rockwool?

Neither is better for every grow. Rapid Rooters are organic peat and need no buffering. Grodan stone wool leaves the factory alkaline, so you condition it in pH adjusted water first. In return, rockwool plugs give uniform density from plug to plug and press straight into larger blocks.