Lavender is a popular, drought-tolerant perennial herb prized for its fragrant flowers and silvery-green foliage. This Mediterranean native thrives in sunny, dry conditions. Success in the garden depends heavily on providing the correct amount of space, which is the most important factor for ensuring the plant’s health and maximizing its blooms. Proper spacing allows the plant to develop its natural mounding shape and prevents common problems arising from overcrowding.
Spacing Requirements for Different Varieties
The appropriate distance between lavender plants is not uniform; it is determined entirely by the species and cultivar’s mature size. Since lavender is a shrub that expands in width over time, spacing must be calculated based on the plant’s final expected diameter. This planning ensures that the foliage of neighboring plants does not touch once they reach their full potential.
Small Varieties
Smaller varieties, such as many types of English lavender (Lavandula angustifolia), require the least amount of room. Compact cultivars like ‘Munstead’ or ‘Hidcote’ typically mature to a width of 18 to 24 inches. A spacing of 18 to 24 inches between plants is ideal for individual mounds, allowing adequate light and air circulation.
Medium Varieties
Medium-sized varieties, including Spanish lavender (L. stoechas) and certain French lavenders (L. dentata), need a moderate increase in planting room. Their mature spread can range from 24 to 30 inches. Spacing these types roughly 24 to 36 inches apart accommodates their eventual size and prevents dense planting.
Large Varieties (Lavandins)
The largest types, known as Lavandins (L. x intermedia), are vigorous hybrids that demand the most space due to their sprawling, shrub-like growth. Cultivars like ‘Grosso’ or ‘Provence’ can easily reach a width of 3 to 4 feet at maturity. These plants should be spaced a minimum of 3 to 4 feet apart to allow full development.
Room Requirements for Container Growing
When lavender is grown in pots, the focus shifts to volumetric capacity to accommodate the root system of a mature plant. For most common varieties, an established lavender plant needs a container with a diameter of at least 12 inches.
The ideal size for most English lavenders and smaller hybrids is a pot measuring 16 inches in diameter and depth. This volume provides sufficient space for the roots to spread, which is necessary for nutrient uptake and stability. Larger, more vigorous Lavandins may require a container up to 20 to 24 inches in diameter to prevent the plant from becoming root-bound.
Depth is as important as width, and the container needs to be at least 12 inches deep to support the root structure. Porous materials like unglazed terracotta are often preferred. They allow moisture to evaporate through the pot walls, promoting better root aeration than plastic containers.
Why Proper Spacing is Essential for Plant Health
The consequence of inadequate spacing is primarily the restriction of air circulation around the plant’s foliage. Lavender is intolerant of stagnant, humid conditions, and dense planting traps moisture around the leaves and stems. This creates a habitat for fungal pathogens.
This moisture buildup is the primary cause of gray mold, also known as Botrytis blight, a fungal disease that can be fatal to lavender. Allowing air to flow freely through the space between plants acts as a natural defense, rapidly drying the foliage after rain or heavy dew.
Overcrowding also forces plants to compete intensely for resources within the soil. When roots are packed closely together, they struggle to access sufficient water and nutrients, leading to stress and stunted growth. This competition prevents the plant from developing a robust root system, resulting in weaker stems and reduced bloom production.