From the plant's perspective, lavender thrives in dry, well-drained soil. Its roots are adapted to absorb water efficiently but are highly susceptible to rot if left in soggy conditions. When overwatered, the roots suffocate due to lack of oxygen, leading to browning leaves and stems. The plant's natural response is to conserve energy by sacrificing older foliage, which turns brown as it dies off. To avoid this, ensure the soil dries out between waterings and plant lavender in sandy or gravelly soil to mimic its native Mediterranean habitat.
Lavender plants despise "wet feet." If the soil retains too much moisture, the roots struggle to function properly. From the plant's viewpoint, compacted or clay-heavy soil acts like a prison, trapping water around the roots. This stress triggers browning as the plant attempts to reduce water loss by shedding leaves. To help your lavender, amend the soil with coarse sand or perlite to improve drainage and create a more hospitable environment for the roots.
Fungi such as Phytophthora or Fusarium can invade lavender roots, especially in damp conditions. From the plant's perspective, these pathogens block nutrient and water uptake, causing leaves to brown and wilt as the plant starves. The browning often starts at the base and moves upward. To protect your lavender, avoid overhead watering and ensure proper air circulation around the plant to reduce humidity, which fungi thrive in.
Lavender is a low-fertility plant and prefers lean soil. Excessive nitrogen, for example, can cause rapid but weak growth, making the plant more prone to browning and disease. From the plant's perspective, too many nutrients disrupt its natural growth cycle, leading to stressed, discolored foliage. Avoid heavy fertilization; instead, use a light application of compost or a balanced, slow-release fertilizer sparingly.
Lavender is adapted to sunny, arid climates. If grown in shade or high humidity, the plant may respond by browning as it struggles to photosynthesize efficiently. From the plant's viewpoint, low light reduces energy production, while high humidity encourages fungal growth. Ensure your lavender receives at least 6–8 hours of direct sunlight daily and is planted in an area with good air movement.
In colder climates, lavender can suffer from frost or freeze damage, which manifests as browning stems and leaves. From the plant's perspective, freezing temperatures rupture cell walls, causing tissue death. While some varieties are cold-hardy, others may need protection. Mulching lightly (without smothering the crown) can help insulate roots, but avoid heavy covers that trap moisture.
Insects like spittlebugs or root-feeding nematodes can stress lavender, leading to browning foliage. From the plant's viewpoint, pests drain resources and introduce wounds that may become infection sites. Physical damage from pruning or animals can also cause localized browning. Inspect your plant regularly and prune damaged parts with clean tools to prevent further stress.
Older lavender stems naturally turn woody and brown over time. From the plant's perspective, this is a normal part of growth as it allocates energy to new shoots. Regular pruning (about one-third of the plant annually) encourages fresh growth and prevents excessive woody, brown stems from dominating the plant.
