Lavandula dentata (French Lavender)

Lavandula dentata, commonly known as French lavender or fringed lavender, is a versatile and highly aromatic plant prized for its beautiful appearance, hardiness, and wide variety of uses. It has a distinctive fragrance, unique foliage, and showy flowers that make it a favorite among gardeners and herbalists alike.

French lavender refers to two distinct species of lavender: Lavandula dentata and Lavandula stoechas, which should not be confused. While both are commonly called French lavender, they differ in appearance and characteristics. L. dentata has toothed leaves and a resinous fragrance, whereas L. stoechas (also called Spanish Lavender) is known for its “rabbit ear” bracts and strong camphor-like scent.

French Lavender – Lavandula Dentata: An In-depth Look

French lavender is a perennial shrub prized for its soft, gray-green foliage and uniquely fringed leaves, which are serrated or “toothed” (hence the species name “dentata,” which means “toothed” in Latin). Its striking flowers are borne on tall spikes that rise above the foliage. While the scent of French lavender is less sweet and more herbal than English lavender (Lavandula angustifolia), it is still fragrant and highly valued in gardens and landscaping.

Native: Lavandula dentata is native to the Mediterranean basin, Eritrea, Ethiopia, Yemen, and the Arabian Peninsula. Lavender belongs to the Lamiaceae family, which includes many aromatic herbs like basil, rosemary, oregano, mint, and sage.

Plant Type and Habit:  French Lavender is an evergreen perennial shrub. It grows as a bushy, rounded shrub with upright flower spikes that rise above the foliage.

Size: Typically grows 2 to 3 feet (60 to 90 cm) tall and wide, making it a compact and manageable shrub for gardens and landscapes.

Flowers: Lavandula dentata produces dense, cylindrical spikes of purple-blue flowers flowers. The spikes are topped with showy, purple tufted bracts that resemble rabbit ears, a characteristic feature of this species.

The flowers are highly aromatic, featuring the classic lavender scent found in other species of the genus. However, they are less sweet than English lavender, which has a more rosemary-like fragrance.

French lavender is a prolific bloomer, often flowering continuously throughout the growing season. It can bloom year-round in warmer climates, but its primary bloom period is from late spring to fall. In cooler regions, it tends to bloom from early summer to early fall. The extended bloom time is one of the reasons Lavandula dentata is popular in gardens.

Foliage:  One of the most distinctive features of French lavender is its foliage. The leaves are gray-green, aromatic, and finely serrated or “toothed,” giving them a fringed appearance. This unique leaf shape sets it apart from other lavender species. The foliage remains evergreen in mild climates, providing year-round interest in the garden.

Hardiness:  Lavandula dentata is hardy in USDA zones 8-11. It thrives in warm, dry climates and is highly tolerant of heat. It may not survive prolonged exposure to freezing temperatures and is unsuitable for colder regions without protection or indoor growing.

Uses: French lavender is often used as an ornamental plant in gardens, borders, and containers due to its attractive flowers and foliage. It is commonly used in hedges, borders, and rock gardens due to its compact size and continuous blooming habit. This lavender is particularly popular in Mediterranean and xeriscape gardens, where its drought tolerance makes it a valuable addition.

Wildlife: The flowers are a magnet for bees, butterflies, and other pollinators, enhancing biodiversity in the garden.

Deer and Rabbits: Lavender is deer and rabbit resistant, owing to its fragrant foliage, making it an excellent choice for gardens plagued by these pests.

Drought Tolerance: This lavender is highly drought-tolerant once established, requiring minimal watering and thriving in dry conditions.

Toxicity: Lavender contains compounds toxic to dogs, cats, and horses if ingested in large quantities, leading to symptoms such as nausea, vomiting, and lethargy. Use caution around pets.

Invasiveness:  French lavender is not considered invasive in most regions. It typically does not self-seed prolifically or spread aggressively like some other plants. However, in certain regions with climates similar to its native Mediterranean habitat, it can naturalize and spread in disturbed areas.

Benefits:

• Low Maintenance: French lavender is relatively easy to care for, requiring minimal watering and pruning once established.
• Extended Bloom Time: Its long bloom period provides continuous color and fragrance in the garden, attracting pollinators throughout the growing season.
• Drought Tolerant: As a water-wise plant, it’s ideal for xeriscaping and gardens where water conservation is a priority.
• Versatile: Lavandula dentata can be used in various garden settings, from borders and containers to wildlife gardens and aromatic plantings.
• Pollinator-Friendly: The flowers attract bees, butterflies, and other pollinators, supporting the local ecosystem.

How to Grow and Care for French Lavender

Choosing the Right Location

French lavender thrives in full sun and well-drained soil. Choose a location that receives at least 6–8 hours of sunlight per day. French lavender is drought-tolerant and prefers dry, sandy, or gravelly soils with good drainage. Avoid planting it in heavy, clay soils or areas with poor drainage, as it is susceptible to root rot.

Planting French Lavender

• Soil Preparation: Before planting, amend the soil with organic matter like compost to improve its drainage and texture if necessary. French lavender prefers slightly alkaline to neutral soil with a pH between 6.5 and 8.0.
• Spacing: Space your plants about 24-36 inches (60-90 cm) apart to allow for proper air circulation and growth.
• Planting Time: Plant French lavender in spring or early summer after the last frost in cooler climates. In warmer climates, you can also plant in fall to allow the roots to establish before the heat of summer.

Watering

Water young plants regularly until they are established, but avoid overwatering. Once established, French lavender is drought-tolerant and only requires watering during prolonged dry periods. Water deeply but infrequently, allowing the soil to dry out between watering sessions. Overwatering can lead to root rot, so it’s important to err on the side of underwatering once the plant is mature.

Fertilizing

French lavender does not need much fertilizer, as it prefers lean, low-nutrient soils. In fact, over-fertilization can lead to excessive foliage growth and fewer flowers. If necessary, apply a light dose of a balanced, slow-release fertilizer in the spring, or add a thin layer of compost around the base of the plant to enrich the soil.

Pruning

Regular pruning helps maintain the plant’s shape and encourages bushy growth. Prune French lavender lightly in the spring as new growth appears, removing any dead or damaged stems. After the plant has bloomed, trim back about one-third of the plant’s growth to prevent it from becoming woody and leggy. Avoid cutting into the old, woody stems, as lavender does not regenerate well from old wood.

Mulching

In areas with hot summers, mulch around the base of the plant with gravel or small stones to keep the roots cool and prevent weed growth. Avoid using organic mulch like wood chips, as it can retain too much moisture around the base of the plant.

Harvesting French Lavender

Harvest French lavender when the flowers are fully open and fragrant. Use sharp scissors or pruners to cut the flower stems, leaving some green growth behind. French lavender can be used fresh or dried for a variety of purposes, including sachets, potpourri, crafts, and aromatherapy. To dry lavender, bundle the stems and hang them upside down in a cool, dark place with good airflow for 2–4 weeks.

Propagation of French Lavender

French lavender can be propagated through seeds, cuttings, or division. The most reliable method is taking semi-hardwood cuttings in late summer or early fall. Simply cut 4-6 inch stems, remove lower leaves, dip in rooting hormone, and plant in well-draining soil. Keep moist until roots are established.

French Lavender – Pests, Diseases, and Common Problems

While French lavender is relatively low-maintenance and resistant to many common garden pests and diseases, gardeners may still encounter a few issues.

Pests

• Aphids: Aphids are small, soft-bodied insects that feed on the sap of lavender plants. They often cluster around new growth or flower buds, stunting growth and causing leaves to curl. A strong spray of water or insecticidal soap can help control aphids.
• Spider mites: These tiny pests are often found in dry conditions, feeding on the undersides of lavender leaves. Spider mites can cause leaves to become stippled and turn yellow or bronze. Keep humidity levels up to prevent infestations or spray plants with water to dislodge mites.
• Whiteflies: Whiteflies can sometimes infest French lavender plants. These small, winged insects feed on sap, causing the plant to yellow and weaken. Use insecticidal soap or neem oil to manage them..

Diseases

• Root rot: One of the most common diseases affecting French lavender is root rot, typically caused by overwatering or poorly draining soil. Root rot leads to yellowing leaves, wilting, and eventual plant death. To prevent this, ensure the soil is well-draining and avoid excessive watering.
• Fungal Infections: In humid or overly moist conditions, lavender can be susceptible to fungal diseases like powdery mildew and botrytis blight. These infections may manifest as white, powdery spots on leaves or gray mold on flowers. To reduce fungal issues, improve air circulation around the plant and avoid overhead watering.
• Leaf spot: Leaf spot diseases can cause dark, water-soaked lesions on lavender leaves. This usually results from wet, humid conditions. To avoid this, maintain good air circulation around plants and water at the base, keeping leaves dry.

Common Problems

• Leggy Growth: French lavender can become leggy and woody over time if not pruned regularly. Prune the plant after flowering to encourage denser, bushier growth and prevent the plant from becoming too sparse.
• Yellowing Leaves: Yellowing leaves can be a sign of overwatering, nutrient deficiency, or root rot. Ensure the soil drains well, water sparingly, and check for signs of root rot.
• Frost Damage: French lavender is more sensitive to cold temperatures than other lavender species. Frost can cause dieback or damage to foliage. In colder climates, consider growing it in containers that can be brought indoors during the winter, or provide frost protection.

Frequently Asked Questions

What is the Difference Between Lavender and French Lavender?

Lavender typically refers to Lavandula angustifolia (English lavender), which has a sweet, floral fragrance and narrow, gray-green leaves. French lavender (Lavandula dentata) has toothed leaves and a more herbal, resinous scent. French lavender is also less cold-hardy but blooms longer and tolerates heat better than English lavender.

Does French Lavender Come Back Every Year?

Yes, French lavender is a perennial in warmer climates (USDA zones 8-11). It will return each year as long as it is protected from frost and receives proper care. In colder climates, it may not survive winter outdoors unless protected or grown in containers.

Where Does French Lavender Grow Best?

French lavender grows best in warm, sunny locations with well-drained soil. It thrives in Mediterranean climates or areas with similar conditions—hot, dry summers and mild winters. It prefers slightly alkaline to neutral soil and performs well in both the ground and containers.

Is French Lavender Hard to Grow?

French lavender is relatively easy to grow if planted in the right conditions. It requires full sun, well-drained soil, and minimal watering once established. The most common issue is overwatering or planting in poorly drained soil, which can lead to root rot.

Does Lavender Grow Better in Pots or Ground?

Lavender, including French lavender, can grow well in both pots and the ground. However, growing in pots allows for better control of soil drainage and makes it easier to bring the plant indoors in colder climates. In the ground, lavender has more space to spread, but ensuring well-drained soil is crucial.