Pam Baker, Little Lavender Farm
One of the reasons we love lavender is that it is not a fussy, demanding plant. However, there are a few things that we can do to make our lavenders happy, and amending our soil is one of those things. There are a few reasons to amend the soil around your lavender plant: 1) creating favorable soil texture, 2) balancing pH levels, and 3) adding nutrients.
Creating Favorable Soil Texture
Soil texture is an important consideration in lavender health. While the ideal soil texture for lavender plants is loose, sandy loam which contains large particles for air and water to move through, it is possible to amend your soil to create a favorable environment for your lavender plants. Of course, what you will add to your soil depends upon the type of soil that you are wanting to amend. If your soil already is loose and allows for the movement of air and water, then you may not need to amend at all. However, if your soil is heavy and clay-like, it would be important to amend your soil to help create more space for your lavender roots to extend. There are several ways to amend:
- Mushroom compost
- Composted leaves
- Perlite and pumice
Balancing pH levels
Soil pH “measures how many hydrogen ions are affecting plant roots. The more hydrogen ions in the soil, the more acidic the soil will be” (Bader 116). The pH scale runs from acidic (pH of 0-6) and alkaline (pH of 8-14). Different plants require different soil pH but Lavender plants happen to thrive right in the middle, in a neutral pH soil of 7. To test the pH of your soil, use a pH test kit to help you to determine how to amend your soil in order to achieve that neutral pH.
- If your soil is too acidic, add dolomitic or calcitic lime.
- If your soil is too alkaline, add sphagnum peat and organic matter. Granular sulfur will also work, but take a little longer.
Lavender doesn’t need much fertilizer to thrive, but you can add specific kinds of fertilizer to the soil to achieve specific objectives:
- Nitrogen: generally, you won’t want to add nitrogen heavy fertilizer to the soil since it will promote leave production, to the detriment of bloom production. However, newly planted lavenders can benefit from a fertilizer that has some nitrogen. After that, nitrogen isn’t needed.
- Phosphorus: Phosphorus helps with root growth, so adding phosphorus sources such as bone meal or bat guano to your soil in the Spring before your plants bloom can be beneficial.
- Potassium: Potassium from sources such as composted fruits and vegetables and kelp meal helps plants deal with stresses such as an extended drought.
Source: Sarah Berringer Bader’s The Lavender Lover’s Handbook