Lavender is a popular choice for container gardening, allowing cultivation on patios and balconies. Successfully growing lavender in a pot requires recreating its preferred dry, well-drained native environment. The container size is the first step in achieving that balance, as the right pot prevents common problems like root rot and stunted growth. Making an informed decision about the container dimensions is paramount because pot size directly influences soil moisture retention and the overall health of the root system.
Essential Pot Size Recommendations
The appropriate size for a lavender container depends entirely on the plant’s current stage of growth and its expected mature size. For a small, newly purchased lavender plant, generally sold in a 1-gallon nursery pot, the initial upgrade should be to a container with a diameter of at least 10 to 12 inches. This size, equivalent to roughly a 2-gallon capacity, provides sufficient room for the roots to expand over the first year without holding excessive amounts of moisture.
For most mature, compact English lavender varieties, such as ‘Munstead’ or ‘Hidcote,’ a pot size of 12 to 14 inches in diameter is often considered the long-term minimum ideal. The depth of the container is as important as the diameter; ideally, the two measurements should be approximately equal to accommodate the root ball and ensure stability for the shrub-like plant.
Larger, more vigorous lavandin hybrids like ‘Grosso’ or ‘Phenomenal,’ which can grow significantly wider, require substantially more space to thrive. These varieties should be placed in containers measuring 16 to 20 inches in diameter, which translates to a capacity of 5 gallons or more. Using a pot that is too small will quickly lead to the plant becoming root-bound and drying out rapidly, requiring constant watering that lavender dislikes.
Conversely, selecting a pot that is drastically too large for a young plant is a common error that can be detrimental. An oversized container holds a disproportionate volume of potting mix, causing the soil to remain saturated for too long after watering. This extended wetness is the primary cause of root rot, which is the most frequent reason for containerized lavender failure. Choosing a container that is only slightly larger than the current root ball is the best strategy for promoting gradual, healthy growth.
Selecting Lavender Varieties for Container Growth
Pot size is determined by the mature size of the specific cultivar, making variety selection an early consideration. Certain types of lavender are naturally better suited to the limited space of a pot due to their compact growth habit. English lavender cultivars like ‘Munstead,’ ‘Hidcote,’ and ‘Dwarf Munstead’ are excellent choices, as they typically mature at a height of 18 inches or less.
Spanish lavender, such as ‘Silver Anouk’ or ‘Bandera Pink,’ and certain French lavenders are also well-regarded for their ability to thrive in containers. These plants often maintain a neat, rounded shape that is ideal for pot culture, reducing the need for aggressive pruning to control size. Checking the plant tag for the mature height and spread is an important step before purchasing a pot, as this information dictates the final container size needed.
The large lavandin hybrids, including ‘Grosso’ and ‘Provence,’ can reach up to three feet in height and width when mature. While it is possible to grow these varieties in containers, they will require the largest pots. They may need to be transplanted into the ground after a few years if their growth cannot be managed through pruning. Focusing on naturally smaller cultivars simplifies the container process by minimizing the need for frequent repotting.
Optimal Container Material and Drainage
The physical construction of the container plays a significant role in managing soil moisture, which is a primary concern for lavender health. Unglazed terracotta or clay pots are generally the superior choices because their porous walls allow water vapor to escape through the sides of the container. This evaporative drying process helps to mimic the arid conditions of the plant’s native Mediterranean habitat.
Plastic or glazed ceramic containers can also be used, but they are non-porous and do not allow moisture to evaporate as readily, increasing the risk of waterlogging. If using these materials, careful attention to watering practices is necessary to ensure the soil has a chance to dry out between applications. Regardless of the material chosen, the container must have multiple, large drainage holes at the base.
Lavender is highly susceptible to fungal diseases caused by wet roots, requiring excellent drainage. Placing a layer of gravel or broken pottery shards at the bottom of the pot should be avoided, as this practice can impede drainage by creating a perched water table within the soil layer. Containers that are wider than they are tall are often preferable, as they provide a larger surface area for the shallow root system to spread.
Choosing the Right Soil and When to Repot
The internal medium of the container must support the plant’s preference for lean, fast-draining conditions. Lavender thrives in a soil that is not overly rich in organic matter and has a slightly alkaline pH, ideally between 6.7 and 7.3. Standard commercial potting soil should be amended to increase its drainage capacity.
Incorporating coarse materials such as perlite, horticultural grit, or coarse sand improves aeration and facilitates rapid water passage. A mixture of one part potting soil to one part coarse sand or perlite is a common recommendation to achieve the correct texture. Since most commercial potting mixes tend to be slightly acidic, adding a small amount of agricultural lime or dolomite can help adjust the pH.
Containerized lavender generally requires repotting every one to two years to maintain vigor. Signs that the plant needs attention include roots circling the inside of the pot, water running straight through the soil, or the plant drying out very quickly after watering. When repotting, the gardener can either move the plant up to a slightly larger container or root-prune the plant and replant it in the same pot with fresh, amended potting mix.