Propagation & Cloning
Rooting Media: Moisture, Oxygen & Temperature
Rooting media must hold enough water to prevent desiccation while retaining pore space and oxygen. Media temperature also changes metabolic rate, water demand, and pathogen pressure.
Key concepts
- Saturation reduces air-filled pore space
- Different media retain and release water differently
- Warm media can accelerate metabolism while excessive heat can increase stress and disease pressure
- The best moisture state depends on media properties, container geometry, and cutting demand
What to measure or observe
- Compare media mass or moisture over time
- Inspect drainage and standing water
- Record media/root-zone temperature
- Check whether rooting failures cluster by tray position or media batch
Common mistakes
- Keeping propagation media continuously saturated
- Judging internal moisture from surface color alone
- Ignoring tray-edge versus tray-center differences
- Changing humidity and media moisture simultaneously without records
Visuals this lesson still needs
- Water-air pore-space diagram
- Media moisture profiles
- Propagation tray hotspot map
- Root-zone temperature workflow