Coco Coir Guide: Choosing, Feeding and Reusing Coco
Coco coir is the growing medium most indoor growers move to after soil. It holds water and air at the same time, it carries almost no food of its own, and it's forgiving once you know its few rules. This guide covers what coco is, the mixes we sell, how it compares with clay pebbles and rockwool, and how to feed and reuse it.
What coco coir is
Coir is the fibre and pith from coconut husks, a by-product of the coconut industry. For growing it is rinsed and buffered - treated so it doesn't hold on to the calcium and magnesium in your feed - which is why you should buy coco made for growing rather than raw coir.
Coco is inert: it gives the plant almost nothing to eat, so you are in full control of the feed. That's its strength, and it's why coco needs a feed made for it.
The coco and coco mixes we sell
| Product | What it is | Good to know |
|---|---|---|
| Canna Coco Professional Plus | 100% coco flakes, rinsed and buffered | 73% water / 27% air; meets RHP quality standards; free of harmful viruses and soil diseases, Canna say |
| Jiffy Pro7 Coco 100% Coir | Pure coir, 50 L | For growers who want plain coco |
| Jiffy Pro7 70/30 Coco Perlite | 70% buffered coco, 30% perlite, 50 L | Lighter and more free-draining than plain coco |
| Ugro XL Rhiza | Buffered coco with mycorrhizae, 70 L | Beneficial fungi added; pre-buffered |
| Gold Label Hydro/Coco 60/40 | 60% clay pebbles, 40% coco, 45 L | For flood and drain, drippers and even Autopots |
Coco, clay pebbles or rockwool?
| Medium | Holds water | Best for |
|---|---|---|
| Coco | Well, with plenty of air | Hand watering or drippers, in pots |
| Clay pebbles | Very little - free-draining | Automated, recirculating systems (flood and drain, drip-recirculating). Also a drainage layer at the bottom of soil and coco pots |
| Rockwool slabs | A lot, evenly | Drip systems on slabs; sterile, so a clean start every run |
| Coco / clay mix | In between | Systems that flood or drip but where you want some water held |
Canna say clay pebbles on their own only suit automated, recirculating systems because they drain so freely - hand-water a pot of pebbles and it dries out fast. More on systems in our hydroponics guide.
Feeding coco
- Use a coco feed. Coco needs nutrients made for it: Canna Coco A & B (see the Canna Coco feed chart), Advanced Nutrients Sensi Coco, Plant Magic Coco A & B (chart), or Biobizz's Coco·Mix schedule in the Biobizz feed chart.
- Feed little and often. Advanced Nutrients' coco chart says coco works best fed at least once a day with plenty of run-off. Never let coco dry right out.
- Calcium and magnesium. With soft tap water or RO water, coco growers usually add a cal-mag product such as Canna CALMAG Agent.
- pH. Athena's chart gives 5.8-6.2 for coco; House & Garden's 5.8-6.3. See our pH and EC guide.
- Pre-soak. Athena pre-soak coco at pH 5.5-5.8 and EC 3.5-4.0 before planting.
Reusing coco
Coco can be used for more than one run. Canna's schedule doubles the Cannazym dose (to 50 ml per 10 litres) when the substrate is reused - the enzymes break down the old roots. Start with fresh coco if the last crop had root problems or pests.
The Cannazym and Hesi PowerZyme pages both say that if you plan to reuse coco, using enzymes throughout is vital. As a rule of thumb, pick out as much of the old root as you can before you replant.
| Product | What its page says | Dose | Good to know |
|---|---|---|---|
| Cannazym | Breaks down dead root matter | 25 ml per 10 L (2.5 ml per litre); 50 ml per 10 L when reusing | Not with liquid oxygen; use within six months of purchase |
| Plant Magic Enzyme | Not bacteria-based; removes dead roots | 2 ml per litre, until the flush | Works best at pH 5.5-6.2; can go with peroxide products |
| Hesi PowerZyme | Breaks down dead plant and root matter; all media, especially coco | 20 ml per 10 L, 1-2 times a week | Not with liquid oxygen |
| Intense Runzyme | Delivers and feeds the bacteria that produce enzymes | 1-2 ml per litre, whole life | Not with liquid oxygen or other peroxide products |
| House & Garden Multi Enzymes | Helps convert nutrients; clears residues from the medium | 1 ml per litre | Matters most in reused coco or a recirculating system, its page says |
| Advanced Nutrients Sensizym | Breaks down dead roots and organic debris; all media | 2 ml per litre | Grow weeks 1-4, bloom weeks 1-7 (Master recipe) |
| Dutchpro Multi Total | Breaks down dead root matter; encourages beneficial bacteria | 2 ml per litre in veg week 1, then 1 ml per litre every other week | Its page calls it a root and growing-medium additive |
For week-by-week doses, see our Canna Coco, Plant Magic, Hesi, Advanced Nutrients and Dutchpro feed charts. All seven products are in our root products section.
Sterile or living - pick one. Liquid Oxygen and Silver Bullet Roots both contain hydrogen peroxide and are the sterile route. The Liquid Oxygen page says not to use it with enzyme products or beneficial bacteria and fungi, and the Cannazym, PowerZyme and Runzyme pages rule out liquid oxygen. Plant Magic Enzyme is the exception: its page says it is not bacteria-based, so it can go alongside peroxide products. If you use BAC Root Stimulator or BAC Bloom Stimulator, leave the enzyme out: their pages rule out any other enzyme product. As a rule of thumb, our root rot guide puts microbes with soil and coco; our mycorrhizae guide covers them.
Quick answers
Can I use coco in an Autopot?
Not on its own in the plastic Autopot pots - we recommend soil, or coco mixed with soil. The Gold Label 60/40 mix says it suits Autopots. See our Autopot guide.
Do I need perlite with coco?
No, but a 70/30 coco and perlite mix drains faster and holds more air, which some growers prefer, especially when hand watering.
Why do my coco plants go pale?
Often calcium or magnesium running short, or a pH out of range. Check pH first, then think about a cal-mag product.
Which enzyme should I use for reused coco?
As a rule of thumb, the one that goes with your feed: Cannazym is on the Canna Coco chart, Plant Magic Enzyme on Plant Magic's Ultimate schedules, PowerZyme on Hesi's charts, Sensizym on Advanced Nutrients' Master recipe, and Runzyme goes with Intense Coco in our coco nutrient bundles. For reused coco, Cannazym is the only one whose page gives a separate dose: 50 ml per 10 L. If you use a peroxide product too, Plant Magic Enzyme is the one whose page says it can go alongside.
More Growers' Guides
- Canna Coco feed chart
- pH and EC meters
- Fabric, Air-Pot or plastic pots?
- Hydroponics: the systems explained
Not sure what you need? Call the shop on 0117 971 3000 or pop in to the Bristol store and we'll help you pick.