lavender soil

Choosing The Best Soil for Lavender Plants

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Do you want to know the secret to growing lavender plants? It’s working with grit! Not the passionate kind of grit, albeit you have it for sure, but working with gritty soils.

The lavender is a landscape plant with a famous function in creating aromatic borders and as a low-level bush in many gardens. It is also cultivated on farms for its essential oil. But in the wild, it naturally grows from the Mediterranean region characterized by having dry summers and poor gritty soils.

They thrive mainly in rocky and sandy soils that are highly deficient in organic matter, dry up quickly, and with a neutral to slightly alkaline soil pH. If you are not from a Mediterranean county, you can still plant lavender plants by using soil that replicates its natural environment.

Where else can you plant lavenders?

Although living in Italy, Spain, or Portugal does give you a climatic advantage to grow lavender plants, it doesn’t mean that you have to go and migrate there just to enjoy these beauties. 

As a matter of fact, lavenders are being grown today in the US to reclaim coal-mined mountains. They are efficient in removing heavy metals and they turn these wastelands purple during the bloom season.

If you do not have the same Mediterranean soil, you can still grow lavenders in three ways:

  • Growing lavender in pots or planters – Pots and planters with holes at the bottom warm and dry more quickly than soil in the ground. This is maybe the only way if you live in a place with abundant rainfall or heavy clay soil. You also become in full control of the potting medium you use and how frequent your watering can be.
  • Growing in raised beds – Planting in raised beds if well-prepared improves drainage of water-retentive soils. Traffic flow that causes compaction is also prevented. The addition of soil amendments or any inputs becomes much easier as well because the gardening space is more concentrated.
  • Growing in amended garden soil – Soil texture refers to the proportion of sand, silt, and clay particles that make up the mineral matter of the soil. Lavenders love sandy soils because the large air spaces of sand allow water to drain quickly. Unfortunately, soil texture is a permanent feature. On another spectrum, soil structure describes the arrangement of the soil particles that influences water absorption, aeration, and drainage too. Regardless of soil texture, you can still grow lavenders by amending the soil structure.

Lavenders need well-draining soil

Lavenders are accustomed to the hot summer, full sun and little rainfall in their natural environment. They have developed special techniques or characteristics that enable them to survive these harsh conditions.

If you put them into soil that retains too much moisture, which is new to them, they become highly susceptible to root rot and fungal diseases. Amend the well drained soil by adding horticultural grit, gravel, perlite, or coarse sand to improve drainage.

Lavender roots also grow only a few inches deep from the soil surface. If you want to grow them in planters, avoid using tall ones that store water at the bottom.

Shallow pots are ideal because they will allow water to evaporate quickly. Do not use regular potting soil mix and those collected directly from the ground because both are too heavy and too water-retaining.

growing lavender

How to test for soil drainage?

If you are unsure about how good your soil drains, you can follow this step-by-step process to test it out:

  1. Dig a hole about 1ft deep and 1 ft wide. The measurement does not need to be exact for the test to work.
  2. File the hole with water. Allow it to drain completely before filling for the second time.
  3. Record how long it takes for the water to be fully drained. If the water is gone after 2 to 3 hours, then you have well-draining soil. Otherwise, you have to amend it first before planting lavenders. 

Lavenders thrive in neutral to alkaline soil

Soil pH measures how acidic or alkaline the soil is. It uses a scale that ranges from 1.0 to 14.0. A pH reading below 7.0 means the soil is acidic while a reading above 7.0 is considered alkaline. A soil pH that is equal to 7.0 is neutral.

The majority of Mediterranean soils are calcareous. They contain a high concentration of calcium carbonate. At the same time, the long drought periods prevent the deep leaching of these compounds so they remain in the soil. Calcium is the same element found in human bones that makes the soil chalky and alkaline.

Soil pH is important in making the nutrients accessible to the plants. Depending on the plant species, they may require different pH levels to sustain their growth. If the level falls out of the preferred range, it severely weakens the plant.

In the case of lavenders, they require a pH between 6.5 to 8.0 which is almost neutral to alkaline similar to their natural growing environment.

How to measure soil pH?

  1. Collect one to three teaspoons full of soil in a beaker or glass bowl. Remove stones, insects, sticks, or any other debris.
  2. Add distilled water to about the same level of the soil.
  3. Thoroughly stir the mix and let it rest for about 30 minutes.
  4. Pour the mix over a coffee filter to separate the solid and liquid parts. Use another clean bowl to collect the liquid solution.
  5. Dip a litmus paper or test strip into the collected liquid solution. Check the product instructions on how long you should do this. Once the color changes, compare the result to a color chart that has a corresponding pH level.
  6. Repeat the test process several times using different samples located in other parts within the perimeter. Record the result and get the average to properly represent the soil pH of your garden.

There are also a lot of test kits and other pH measuring devices available in the market. They can give more accurate results at an affordable price than qualitative testing such as the litmus paper. Having your soil tested regularly does more good than harm and it will save you a lot of resources in the long run.

Most garden soil falls in slightly acidic conditions. To make it more alkaline, you can add an adequate amount of agricultural lime because it contains calcium. However, it takes time and is a repetitive process before results can be seen. 

Roots of lavender can reach up to 18 inches in depth at full maturity. So make sure to amend the soil as deep in order to accommodate the roots.

If you are a beginner, it’s better to do it in a trial-and-error way than to risk putting too much lime in one go. Remember, patience pays off in gardening. But if you have the privilege, it is always best to consult an expert to determine exactly how much lime should be added.

Lavenders appreciate nutrient-poor soil

The humus layer, where the ground gets its nutrients from, is usually lacking in Mediterranean soils. The high solar radiation in the area may break down organic materials rapidly but is greatly limited by the sparse vegetation.

Leaching is also significantly high in gravelly soils removing any nutrients formed from the decomposition process even with little precipitation.

Similar to its native environment, lavenders will thrive best in nutrient-poor soil. If they are planted in soils with high fertility, they become leggy and produce only a few flowers.

It is also not recommended to add synthetic fertilizers to boost the growth of lavenders. Too heavy fertilizers can either burn or kill them. The addition of a few compost, bone meal, or kelp during springtime is more than enough to give support for the year to come.

Never fertilize in fall because it will encourage new growth that will only be damaged as the winter comes. It will be a waste of time and resources.

How to prepare garden soil for lavenders?

Start with the end in mind. Make plans on how you would like to plant your lavenders. The plan you created will be important in achieving your goals whether it is for the purpose of aesthetics or you would like to have some harvest. 

Begin by knowing your soil.  If it is your first time, you can ask a soil expert to make an analysis. The analysis should at least give you data about soil pH, organic matter content, N-P-K, and texture. Otherwise, you can personally do the tests using basic tools and methods in a trade-off for more accurate results.

Use both the result of the analysis and lavender growing requirements to make necessary adjustments. Is the soil draining enough? Do you need more grit? Will you have to create raised beds? Should you add more lime? Is compost necessary?

Make sure you have made all necessary amendments before planting. The soil will be the home and the ultimate foundation of your lavenders. The best soil is not the richest one as we always initially think of but the one that understands its specific needs and provides them accordingly.

Soil mix for lavenders

As long as the growing medium and the environment are to their liking, lavenders can thrive best. Container-grown Lavandula needs a potting medium that is well-draining, neutral to slightly alkaline, and not too fertile, similar to the characteristics of their native range.

To have a good potting mix, you can use a commercial well-draining potting soil and blend it with cactus and succulent soil at almost equal proportions. You can also use perlite, grit, or coarse sand instead of a succulent mix.

Take note that there is no right or wrong mix as long as it is good for your lavenders. Even commercially sold potting mixes vary from brand to brand and place to place. Feel free to experiment and explore creating different mixes until you get what works best for you.

Fun facts about lavender flowers

  • Lavender bushes were used by Egyptians for perfumery and embalming over 2,500 years ago.
  • The Bible has more than a hundred accounts of lavenders or spikenards being used for purification rituals, healing, and perfumes by the nobilities and high priests.
  • Lavenders are mostly in shades of purple but there are varieties that grow pink, white, and yellow flowers.
  • There are more lavender varieties than species of lavender today. There are over 450 known varieties and only 45 species.
  • The lavender flowers symbolize calmness, purity, grace, devotion, serenity, and silence.
  • Luteolin which is found as an antioxidant in lavender honey can help boost the immune system, protect the eyes from UV rays, and maintain healthy blood sugar levels.
  • These fragrant flowers can repel insects such as mosquitoes.
  • The essential oil is widely used for aromatherapy to promote relaxation and reduce anxiety.
  • It also contains natural anti-microbial and anti-inflammatory properties.

See more: Companion plants for lavender

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