Choosing a suitable potting soil for lavender is the first and most important step in cultivating the plant. If you start with the wrong soil, growing lavender will just be a miserable experience for you.
Many gardeners who try to grow lavender for the first time fail terribly because they pick an unsuitable growing medium for the plant without knowing so. And even if they figure out the problem, their attempts to solve it can sometimes exhaust their lavender plants.
To guarantee that you don’t make the same mistake, we wrote this article that will examine the soil needs of lavender and the potting soil mix in which this herb will grow perfectly.
An Overview of Lavender’s Soil Needs
Some say that lavender grows best when neglected. All that you need to do to see your lavender plants flourishing is to water and feed them as little as possible. But what is the reason behind this?
Lavender has originated in some dry regions of Europe and the Mediterranean. The soil found in those areas is of poor quality and has very strong drainage. So, lavender has adapted to grow with a limited amount of water and nutrients.
We now know that lavender prefers a soil that is loose enough to drain out water, especially if it’s growing in a container.
Heavy clay soil, for example, will make your lavender suffer. Its high compactness and retention capacity are the exact opposite of what we are seeking.
Besides that, lavender hates acidic soils. Any soil with a pH of 6 or less can either shorten the lifespan of your plant or kill it at once.
Lavender prefers a sandy loam soil that is well-aerated, well-drained, and mildly rich with nutrients.
The Perfect Potting Soil for Lavender
There are several potting soil mixes that have been used by gardeners to grow lavender. Yet few of these are considered risk-free and reliable.
Well-drained potting soil alone, for instance, doesn’t work for the plant. It drains water slower than what lavender requires for its survival. Even potting soil mixes that are made to drain water faster than the regular ones aren’t enough on their own.
That means amending the soil is an essential step before using it to grow lavender. Still, some amendments, despite having the ability to improve the soil for lavender, can harm the plant in many other ways.
Pumice can make the soil less compacted, which allows more air to traverse it. But pumice can also retain water and for this reason, it’s mostly used to improve heavy soils for moisture-loving plants.
Some organic matter can increase the drainage of the soil but can also boost its nutrient content. This feature is problematic for a plant that is accustomed to growing with a low quantity of minerals. Many of these organic substances can also make the soil more acidic.
Considering that, it’s important to pick a soil amendment that can loosen the soil and increase its drainage without adding more nutrients to the medium or decreasing the pH.
According to science and from our experience, the best two amendments that can achieve our goal are perlite and coarse sand.
Both perlite and sand can discharge excess water without interfering with the soil’s acidity and nutrient composition.
Preparing the Perfect Mix: 2/3 High-Quality Potting Soil + 1/3 Perlite or Coarse Sand
To prepare the perfect soil mix for your lavender plant, you first need to have a high-quality well-drained potting soil.
Don’t go for cheap brands that are found in nurseries. These are usually full of pests and have a terrible texture.
We usually use Foxfarm Ocean Forest Garden Potting Soil Mix for our lavender and we highly recommend that you use it too!
Foxfarm is well-drained and has one of the best textures of all potting soils. Its pH is also adjusted at 6.3 to 6.8 and this is perfect for lavender.
Foxfarm Potting Soil
Mix two parts Foxfarm with one part perlite or coarse sand (2/3 Foxfarm + 1/3 perlite or sand) and you get the perfect potting soil for lavender!
This mix has worked amazingly for our lavenders and should work well for your plants too!
It is important to note that you can easily adjust the drainage of this mix by adding more perlite or potting soil. In case your lavenders are getting dehydrated quickly, you can add more Foxfarm. If the plants look over-watered, you can either lengthen your watering schedule or add more perlite.
Alternative Potting Mix for Lavender: ½ Cactus Mix + ½ High-Quality Potting Soil
Instead of using perlite or sand, some gardeners like to combine equal proportions of cacti and succulents mix, such as Hoffman Organic Cactus and Succulent Soil Mix, and well-drained high-quality potting soil to create a suitable growing medium for lavender.
In general, this soil mix is more expensive to prepare than the previous one. For this reason, we advise you to use it only when our standard mix cannot produce the desired results with the lavender species or cultivar that you’re attempting to grow. This rarely happens but remember the formula of this mix just in case.
Important Notes to Keep in Mind
As we mentioned before, fertilizers are unnecessary for lavender, but you can still use them scarcely to promote fast plant growth.
Keep in mind, that sometimes too many nutrients can disturb the life cycle of lavender. For example, too much nitrogen can stop your lavender plants from flowering.
So, you might as well choose a soil amendment low in nitrogen, such as compost that can slowly release nutrients into the soil.
If you use Foxfarm potting soil, you must avoid using any fertilizers for your plants because the soil comes brimming with nutrients.
If your lavender plants outgrow their containers, transplant them to prevent their roots from getting bound.
Make sure you use new potting soil and a new container at least double the size of the old one. This is important because you don’t want to exhaust your plants by transplanting them several times in a brief period of time.
And if the root ball of your lavender plant looks healthy, try not to disturb it during the transplanting procedure.
Drainage of the Container
Drainage is not only dependent on the soil but also on the container in which your lavender plants are growing.
Sometimes, excess water cannot escape your plant containers even if the soil is fast draining. This can be much more dangerous for your lavender plants than slow-draining soil. Trapped water can drown your lavender plants and cause irreversible damage to their roots.
To avoid such a problem, make sure your containers have the best drainage capacity by purchasing high-quality pots. Much like soil, cheap brands of plant containers can be harmful to your plants.
This is everything you need to know about potting soil for lavender. Enjoy growing this herb and don’t forget to share your thoughts in the comments below!