Medium profile

Peat Moss

A lightweight organic medium with high water retention and acidic pH, often blended with aerating materials for soilless hydroponic or fertigation systems.

Troubleshooting

Water runs off dry peat instead of soaking in.

Pre-moisten slowly with repeated light watering or use a wetting approach before planting.

Roots look brown or oxygen-starved.

Improve drainage and aeration, reduce watering frequency, and avoid compacted media.

Maintenance

Avoid compaction by blending with coarse aerating materials.
Monitor pH and alkalinity because peat-based mixes may drift over time.
Do not allow peat to dry completely between irrigations.

Make It Yourself

Moisten dry peat moss gradually because it can be hydrophobic when fully dry.
Blend with pumice, perlite, rice hulls, or sand to improve aeration and drainage.
Adjust pH if necessary before planting, because peat moss is naturally acidic.
Use in containers or beds with reliable drainage and controlled fertigation.

Cost

10 - 50 NZD

Specifications

Water retention: very high
Aeration: medium when fluffed, low when compacted
pH tendency: acidic
Reusable potential: low to medium

Cultivars

Cultivar	Compatibility
Leafy greens	good
Spinach	good
Basil	good
Carrots	moderate
Tomato	moderate

Methods

Method	Compatibility	Notes
Drip Irrigation	good
Ebb and Flow	moderate
Wick	good

Issues

Issue	Description	Remedy
Acidic pH	Peat moss can lower root-zone pH if not adjusted.	Pre-adjust with lime or blend with pH-stable materials as needed.
Compaction	Fine peat can compact and reduce oxygen availability.	Blend with pumice, rice hulls, perlite, or coarse sand.

Advantages

Excellent water retention
Lightweight
Useful in blends
Good for seed starting and moisture-loving crops

Disadvantages

Naturally acidic
Can become hydrophobic when dry
Can compact over time
Sustainability concerns compared with renewable alternatives