The right substrate has a massive influence on growth, nutrient uptake and yield. Complete substrate guide for every growing style.
The choice of substrate is fundamental for successful cannabis cultivation:
**High quality potting soil:**
*Advantages:*
- Easy for beginners
- Buffers pH fluctuations
- Already contains nutrients
- Contains micro-organisms
- Error-preventing
*Disadvantages:*
- Less control over nutrients
- May be pre-fertilised (over-fertilisation)
- Differences in quality between manufacturers
- Drainage often not optimal
- Pests/fungi possible
*Recommended soil brands:*
- BioBizz Light-Mix: Less pre-fertilised
- Plagron Bat-Mix: Organic, rich
- Canna Terra Professional: Balanced
- Compo Sana: Budget option
**Coco-Substrate (coconut fibre):**
*Coco advantages:*
- Excellent drainage
- High oxygen supply to the roots
- pH-neutral (6.0-6.5)
- Reusable
- Difficult to overwater
- Faster growth than soil
*Coco disadvantages:*
- Requires more monitoring
- Daily watering often necessary
- Needs Cal-Mag supplements
- Must be buffered before use
- Higher learning curve
*Coco preparation:*
- Rinse with Cal-Mag solution
- adjust pH to 6.0
- Wash out excess salts
- Expansion in warm water
- Add perlite for extra drainage
**Perlite mixtures:**
*Perlite function:*
- Dramatically improves drainage
- Increases oxygen supply
- Prevents compaction
- Structural stability over time
- Reusable
*Mixing ratios:*
- 70% soil + 30% perlite: Standard
- 50% Coco + 30% Perlite + 20% Vermiculite: Pro-Mix
- 60% soil + 40% perlite: Maximum drainage
- Never 100% perlite (too little support)
**Organic substrates:**
*Compost-based mixtures:*
- Own compost + perlite + vermiculite
- Worm humus as a base
- Organic additives
- Long-term nutrient release
- Building up the soil biology
*Super-Soil concept:*
- Complete nutrients incorporated into substrate
- Only water during the entire grow
- Build-up over several months
- Very advanced
- Best flavour results
**Hydro substrates:**
*Expanded Clay Pebbles:*
- Inert and reusable
- Excellent drainage
- Stable pH values
- Easy to clean
- Standard for hydro systems
*Rockwool/rockwool:*
- Sterile starting position
- Precise nutrient control
- Rapid root development
- pH preparation necessary
- Environmental concerns
*Coco in Hydro:*
- More natural than Rockwool
- Good buffering properties
- Can be combined with other media
- Requires more frequent flushing
**Substrate mixtures for different phases:**
*Seedlings (0-2 weeks):*
- Light, nutrient-poor mixture
- 50% coco + 30% perlite + 20% vermiculite
- Or Jiffy pellets/rockwool cubes
- Sterile conditions important
*Vegetative phase:*
- Standard potting soil
- Or 60% coco + 30% perlite + 10% worm humus
- Medium nutrient concentration
- Good drainage for fast growth
*Flowering phase:*
- Keep the same substrate
- Drainage becomes more important
- No substrate changes in flowering
- Focus on nutrient adaptation
**Substrate-specific irrigation:**
*Soil:*
- Watering
Soil provides a natural source of nutrients, retains water well, and promotes the microbiome, which supports root growth. It is also easy to work with and ideal for beginners.
Coco is a neutral growing medium that provides excellent drainage and aeration, which helps minimize root rot. However, it requires regular fertilization because it does not retain nutrients.
Hydroponics can result in faster growth rates and higher yields because the plants have direct access to nutrients. However, it requires more technical knowledge and precise control of the nutrient solutions.
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