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If you have done much gardening, you have probably already grown several varieties of herbs in your garden or in containers. If you have other plants that grow in acidic conditions, you may be considering planting herbs alongside them. Can you plant herbs with ericaceous compost, or will this be too acidic for them?
Some herbs, such as thyme, garlic, and parsley, can be grown in lower pH soils modified with ericaceous compost. These herbs will benefit from the lower pH and thrive in this environment. Most other herbs prefer slightly acidic soil between pH 6.0 and 7.0 or slightly alkaline soil.
Ericaceous compost is intended for acid-loving plants to provide the right growing conditions, allowing the plants to absorb the nutrients they need from within the soil, but what about herbs? Can you grow herbs in ericaceous compost? We will discuss this potential for herb growing, which you may find surprising.
Is Ericaceous Compost Good For Growing Herbs?
Ericaceous compost is specially formulated to be acidic, with a pH level below 6. It is designed to help acid-loving plants, such as blueberries, rhododendrons, camellias, and azaleas, to grow and flourish.
Can you grow herbs in ericaceous compost? As with other plant groups, different herbs have different pH requirements for their soil.
Each plant has a pH tolerance range but will generally perform well somewhere in the middle of its preferred pH range.
Soil pH is an often neglected aspect of growing plants that many gardeners overlook. You can do everything else right for the plant, but if the soil pH is not within its tolerance level, the plant will underperform and display symptoms of nutrient deficiency.
Ericaceous compost can play an important role in adjusting the soil or growing medium pH to within the optimal pH range for your herbs. This will produce healthy, strong, disease-free plants, which will produce a better harvest.
Adjusting the soil pH with ericaceous compost can be a delicate process to correct the pH balance. A quality soil pH meter
is an irreplaceable piece of equipment if you use this method to grow herbs or any other plants in this compost.
Herbs That Can Grow In Ericaceous Compost
Most plants, including herbs, prefer slightly acidic soil between a pH value of 6.0 and 6.9. However, some herbs prefer a slightly more acidic environment and will perform substantially better if grown in more acidic soil.
The advantage of herbs is that many of these plants are small enough to be interplanted with other larger plants. This means you could utilize the space between other larger acid-loving plants in your garden and herbs in between them.
Some herbs that can grow well in acidic soil are listed in the table below with their preferred pH range.
| Herbs That Can Grow In Ericaceous Compost | |
| Herb | Preferred Growing Environment pH |
| Sage | 5.5 – 7.0 |
| Rosemary | 5.5 – 7.0 |
| Parsley | 5.0 – 7.0 |
| Spearmint | 5.5 – 7.0 |
| Thyme | 5.5 – 7.0 |
| Garlic | 5.5 – 7.5 |
| Basil | 5.5 – 6.5 |
| Dill | 5.8 – 6.5 |
| Oregano | 5.8 – 6.2 |
| Fennel | 5.0 – 6.0 |
The above herbs can grow well in ericaceous compost if provided with the right growing conditions. These conditions include a well-draining soil mix that is enriched with organic matter and kept moist but not waterlogged.
Ericaceous compost provides these conditions and can promote the healthy growth of these herbs. In addition, growing herbs in ericaceous compost can also help to deter pests and diseases that thrive in alkaline soil.
Herbs That Should Not Be Grown In Ericaceous Compost
While ericaceous compost is suitable for some herbs, there are several herbs that you should avoid growing in this type of soil.
These herbs are known to prefer alkaline soil and will not thrive in acidic soil modified with ericaceous compost.
Here are some examples of herbs that should not be grown in ericaceous compost:
| Herbs That Cannot Grow In Ericaceous Compost | |
| Herb | Preferred Growing Environment pH |
| Stevia | 6.2 – 7.2 |
| Lavender | 6.5 – 8.0 |
| Chives | 6.0 – 7.0 |
| Peppermint | 6.0 – 7.5 |
| Marjoram | 6.0 – 8.0 |
| Celery | 5.8 – 6.8 |
| Arugula | 6.0 – 7.0 |
| Lemongrass | 6.5 – 7.0 |
If these herbs are planted in ericaceous compost, they may not receive the proper nutrients and growing conditions they need.
This can result in stunted growth, yellowing of the leaves, and other signs of nutrient deficiencies. It is best to plant alkaline-loving herbs in a soil mix that is neutral to slightly alkaline to avoid these issues.
Although ericaceous compost will not be beneficial for these plants in normal conditions, if your soil is extremely alkaline, you may have yet have use for this type of compost.
Adding ericaceous compost to very alkaline soils will acidify the soil and drop the pH to levels more sustainable for herbs that prefer slightly acidic soils.
Consequently, the choice to use ericaceous compost or not will be driven by the original pH of your growing medium and the best possible pH level for the herbs you are planting.
Monitor Your Soil pH After Amending With Ericaceous Compost
If you have planted your herbs in soil amended with ericaceous compost to achieve the desired pH level, you must periodically monitor the growing medium pH.
The pH value will slowly increase toward the neutral level and will need to be readjusted by adding more ericaceous compost to lower the pH again.
The best way to keep a check on the pH level is to invest in a quality soil pH meter and take readings of the soil pH level every six weeks or so.
Checking the pH on a frequent basis will allow you to catch the pH before it rises too high and give you a chance to modify the soil with another dose of ericaceous compost.
Conclusion
In conclusion, while ericaceous compost is typically used for acid-loving plants, some herbs can also thrive in this type of soil mix. Herbs such as thyme, garlic, and parsley are excellent candidates for growing in ericaceous compost.
However, an important aspect to note is that not all herbs are suitable for this type of soil. Herbs that prefer only slightly acidic soil, such as lavender, lemongrass, and marjoram, will not do well in ericaceous compost.
References
- https://www.gardenersworld.com/how-to/grow-plants/ericaceous-compost/
- https://gardeninglatest.com/ericaceous-compost/
- https://www.lovethegarden.com/uk-en/article/ericaceous-compost-explained
- https://www.gardeningknowhow.com/composting/basics/ericaceous-compost-info.htm
- https://homeguides.sfgate.com/ph-balance-herbs-vegetable-plants-61705.html
- https://extension.umn.edu/vegetables/growing-herbs
- https://howtoculinaryherbgarden.com/best-soil-ph-for-growing-herbs/
- https://homeguides.sfgate.com/ph-balance-herbs-vegetable-plants-61705.html