Grow Mediums

How to choose a grow medium

Watering rhythm, root-zone air, whether the medium brings its own food, and whether you will run it again — those four points pick the medium. Every type below has a page of its own.

1. How you water. Fast-draining expanded clay and coarse perlite take water again almost immediately, so they fit frequent or automated watering. Coco coir, vermiculite and soil hold a reserve between waterings and are kinder if you water by hand.
2. Air against water. Perlite is the air-adder; vermiculite keeps more water and less air than perlite. Most growers want both at once, which is why 70/30 and 60/40 coco-perlite blends sit on the shelf instead of straight coco alone.
3. Inert or living. Rockwool, expanded clay, perlite and washed coco carry no nutrition — the plant only gets what you put in. Living soils land already amended and biologically active, and they are built to be watered rather than fed.
4. Reuse. Rinse expanded clay and it is ready for another run — it does not degrade. Living soils are written to be re-amended every cycle. Way to Grow puts a four-year reuse rating on Professional Coco. Treat rockwool and propagation plugs as single-use.
5. Propagation or full cycle. Cuttings and seed want a small, sterile, air-filled plug, not a 50L bag. That group lives on a separate page.

Our range of grow mediums

Coco coir and coco peat

This is the biggest slice of the collection — 37 products. Loose bags span 10L to 53L. Compressed bricks and blocks swell once wet: the W2G 5kg Professional Coco block takes up to 20 litres of water and opens to about 60 litres. Grades run from fine coco peat through coco chips to 70/30 and 60/40 coco-perlite blends. RHP-certified Cyco and Way to Grow lines sit next to Canna, GreenPlanet and Hy-Gen. Shop coco coir.

Perlite and vermiculite

Heat volcanic rock until it expands up to twenty times its volume and you get perlite: a light granule that drains freely and still wicks moisture from below. Grades go from 4-6mm coarse in a 10L bag to 8-12mm extra coarse in 100L, plus a 20L grow bag. Perlite is used neat or as the aerating third of a coco blend. Vermiculite is the reverse trade — more water, less air — and is used for seed germination, striking cuttings and plants that like staying moist.

Rockwool

Stone fibre, spun, sterile and inert: the usual starting cube here. Grodan and Speedgrow wrapped cubes come in 40mm and 75mm, Delta 10 blocks at 100mm, Hugo blocks at 150mm, plus SBS seedling trays and crop-box slabs so you can finish a cycle in the same material. Shop rockwool.

LECA and expanded clay

Expanded clay balls are pH neutral, sterile and non-degradable. Moisture sits on the surface of each ball and large air gaps sit between them, which is why they suit recirculating systems and aquaponics. Sizes are 8-15mm and 8-16mm in 10L, 25L and 50L bags, including the Green Planet 25L bag. It does not break down, so it is the medium growers wash and reuse most often. Shop LECA clay balls.

Soils and living soils

Living soils come already amended and biologically active. They are built for water-only growing and for re-amending between cycles rather than tipping the pot out. The Easy As Organics water-only 25L mix is peat, perlite, scoria, certified organic compost and 5% biochar with a Bacillus inoculant; the maker states it is AS3743 compliant. Grow Kings' and Bio Diesel's living soils and Canna Terra Professional sit next to it. Shop soils and living soils.

Propagation mediums

Seed and cuttings sit in their own group: Eazy-Plug coco plug trays in 12, 24 and 77 cells, Jiffy-7 42mm peat pellets, ROOT!T coco coir dry plugs in 24-cell trays and 60-plug refills, plus rockwool cubes. Small cells, high air, sized for a tray rather than a pot. Shop propagation mediums.

The pot you pick changes how the same medium behaves: coco in a fabric pot dries far faster than the same coco in plastic. Containers, saucers, stands and trays live on the pots and trays range.