What potting soil is best for herbs?
Written by
Liu Xiaohui
Reviewed by
Prof. Martin Thorne, Ph.D.Choosing the right potting soil is critical for your herb garden. Mediterranean plants prefer soil that is gritty, fairly alkaline, and extremely well-drained. In contrast, moisture-loving varieties, such as those with lush foliage or a tendency to bolt in dry conditions, prefer rich, compost-based mixes that retain moisture. In all cases, the soil ingredients must match the plant's habitat to prevent both root rot and loss of flavor.
Mediterranean herbs, such as rosemary, require a soil that closely resembles their native coastal environment. A mixture of three parts coarse sand to two parts compost will suffice, with a small amount of crushed limestone added to maintain the proper degree of alkalinity. This keeps their roots fairly dry, yet encourages them to go deep. I have seen rosemary thrive in this composition when assuredly it would have perished anywhere else.
Basil and parsley like a little different approach. They appreciate moisture-retaining soil but also require neutral conditions. Blend one part topsoil, one part compost, and one part coconut coir. This should provide a balanced mix that retains water without being too wet. You can also add vermiculite for extra water retention during hot spells. The more moisture you can provide, the tastier and more tender the leaves will be.
Mediterranean Herbs
- Soil Texture: Gritty with 50-70% coarse sand
- pH Level: Alkaline 7.0-8.0 adjusted with limestone
- Drainage: Fast-draining to prevent root rot
- Container Tip: Use terra cotta pots for evaporation
Moisture-Loving Herbs
- Soil Texture: Loamy with 30% water-retentive materials
- pH Level: Neutral 6.5-7.0 maintained with compost
- Drainage: Moderate to retain moisture
- Container Tip: Plastic pots conserve water longer
Container herbs might need a little extra tender love and care. Be sure to opt for a lightweight mix containing perlite or vermiculite, both of which are beneficial for drainage. (Be sure that your pots are well-draining as well.) Terra cotta pots dry out faster than plastic ones. Water when the top inch feels dry. Soil not mixed properly will "lock out" nutrients and may cause disease problems.
Feed your soil with seasonal adjustments. Renew container soil once a year. Or, top-dress garden beds with compost every spring. Test their pH once every three months. These practices will keep your herbs productive for many years to come. Healthy soil produces healthy plants, and consequently, robust flavors.
Read the full article: Best Soil for Herbs: Ultimate Growing Guide
