Plugs & Substrates

Choosing a plug

Root Riot cubes are a soft, organic compost sponge that holds moisture and air in the right balance. Cuttings root in them quickly and the whole cube goes into the next pot, so nothing is disturbed. They come in trays and refill bags.

Rockwool cubes are inert, sterile and hold a lot of water, which suits hydroponic systems: a small propagation cube fits into a 75mm transplanting cube, and that fits a slab or a net pot. Soak rockwool in water adjusted to about pH 5.5 before use.

Jiffy 7 pellets are compressed peat in a fine net that swells with water: cheap, tidy and good for seeds. Jiffy Botanian pots are peat-free and biodegradable, so they are planted pot and all. Plug Life 80/20 is a peat mix in trays of 104 for larger batches.

Tips

Keep plugs moist, not soaked, and warm: a heated propagator makes a real difference in a cold room. Cover seedlings and cuttings to hold the humidity until roots show, then vent them a little more each day.