30% coarse sand or gravel to 70% organic compost or potting soil is the best soil ratio for growing lavender in pots and other containers. To increase the pH and make the mixture somewhat alkaline, add one tablespoon of garden lime to the mixture. The ideal soil conditions of the lavender’s native Mediterranean area are replicated in this soil mixture.
Continue reading to learn more about the particular soil needs of potted lavenders, the best soil mixture to guarantee robust flowers and scent, and how the size of the pot or container you use impacts lavenders.
Table of Contents
Soil Requirements For Lavenders in Pots
In order to get the most out of your lavender in terms of flowering, scent, oil, and longevity, you must match the soil conditions of their native environment when growing lavenders in pots.
Both the type of soil used and how often it is watered matter when growing lavender in pots. (Read my post on how often to water lavender for advice on watering.)
Lavenders do have a tendency to flourish in neglected areas, but for the maximum growth and bloom, they require extremely certain soil conditions. This comprises:
- Alkaline ground. Although it will grow well in soils with a pH of 6.5-8, which varies from moderate acidity to alkaline, your potted lavender will be most content in alkaline soil.
- gravelly or sandy soil with good drainage. If the lavender is to survive the winter in a pot, it must have well-draining soil. Lavenders detest sitting in cold, wet soil since doing so increases their risk of contracting the fungus that causes root rot. Since the roots of the lavender plant want to dry out between waterings, the soil must drain extremely rapidly and not retain much water.
- Medium to low fecundity. Lavenders have developed a special adaptation to sandy soils with a dearth of nutrients. Gardeners frequently make the error of planting lavender in rich soils and fertilizing it to promote growth and flowering. High fertility soils cause lavender plants to develop languidly with a lot of foliage and few blooms. The lavender leaves will turn yellow with too much nitrogen.
- unconfined soil structure. Lavenders appreciate a porous soil structure with a relatively high proportion of course sand or gravel because it provides oxygen, allows water to drain efficiently, and gives the roots room to grow. Compacted soil is not conducive to lavender growth.
The Optimal Soil Mix for Lavenders in Pots and Containers
The first consideration is making sure the soil mixture contains a sufficient quantity of coarse sand or gravel. Both of these substances are excellent for growing lavender and offering the ideal framework for proper drainage.
It is crucial to stress that fine sand, which contains significantly smaller particles and is less porous, is inferior to coarse builders sand in every way.
In order to prevent root rot, lavender plants require oxygen in the soil for root respiration. When growing lavender in pots, it is crucial to uniformly distribute the large sand and gravel particles throughout the soil mixture.
Only the large course sand or gravel particles will offer the proper structure to allow for adequate soil oxygenation and ideal water infiltration conditions.
Too much moisture in the soil is one of the most frequent causes of lavender death. Additional watering will exacerbate the issue, and root rot will unavoidably affect the plant.
This is why maintaining the ideal soil structure necessitates the use of sand or gravel. Compost and minerals must be used to achieve the ideal soil moisture level for lavenders because sand and gravel do not absorb and retain water in the same way that rich organic soils do.
I always advise using an inch of gravel in the bottom of the pot when preparing lavender in pots to assist keep the drainage pores at the base of the pot clear and well-draining.
Around 30% of the soil mix should be sand or gravel, and the remaining 70% should be well-rotted compost or store-bought organic potting soil.
You can estimate this by eye, but be generous with your amendment because too much sand or gravel is always better for the lavender than not enough.
For lavenders to grow healthily, produce the most flowers and aroma, and have the best drainage, the organic soil should be combined with sand or gravel.
Make sure that each element is evenly distributed throughout the soil to maintain a consistent soil structure and to ensure that the deeper roots have easy access to oxygen.
Because sand and gravel do not significantly provide nutrients to the soil, the fertility of the compost will be balanced out, allowing you to mimic the low- to medium-fertility conditions of the lavender’s original Mediterranean setting.
Nutrient-enriched potting soil should be avoided because it will encourage lanky growth and fewer blossoms.
Store-bought potting mixtures often have a pH of 7 (neutral), but I would advise you to add agricultural lime or wood ash to the soil to raise the pH to the ideal alkaline range for lavender.
Manure-containing compost should never be used since it contains too much nitrogen and soluble salts for lavender cultivation.
Make cautious not to compact the dirt when planting the potted lavender in the soil mixture because doing so will force the air out and make it harder for the roots to take root.
(Read my article on how to care for potted lavender.)
The Size of the Pot is Important
The container should ideally be 16 inches across and correspondingly deep in order to successfully grow lavender. This will ensure that there is enough dirt in the pot for the roots to have access to moisture, nutrients, and room to grow.
This size pot or container also has enough soil to protect the roots from colder weather and stop the soil from drying out too soon in the summer heat.
I have a post on which containers and pots are excellent for growing lavender because it’s crucial to choosing the proper one for a healthy plant.
Read my article on how to successfully transplant lavender if you’re transplanting the plant from one container to another to find out how to lessen transplant shock.
- 30% sand or gravel and 70% organic potting soil make up the perfect soil mixture for growing lavender in pots or containers. To make sure the soil is alkaline, which is lavenders’ optimal soil pH, add a spoonful of lime.
- By adding sand or gravel, the soil will be given the ideal structure for growing lavenders, allowing water to permeate and the roots to obtain oxygen. Additionally, the sand or gravel aids in re-creating the low to medium soil fertility that lavenders require for their greatest flowering.
- Verify that the sand and organic compost are distributed equally throughout the pot.
- To keep the drainage pores open and allow extra water to drain, add a layer of gravel to the pot’s base.
- A pot or container with a 16 inch diameter will guarantee that there is enough soil in the pot or container to keep the roots warm in the winter and that the roots have enough room to spread out and get the nutrients and water needed for a healthy lavender plant.