Lavender, a versatile herb widely used in cooking, also adds a striking touch to borders and perennial gardens, offering a continuous display of color from early summer to fall. Characterized by its silvery-green leaves, upright flower spikes, and compact shrub-like structure, lavender is well-suited for creating informal hedges. Beyond its ornamental value, this herb is perfect for harvesting, contributing to fragrant floral arrangements, sachets, and potpourri.
The most commonly cultivated variety is Lavandula angustifolia, also known as English lavender, previously named L. officinalis. Hardy up to USDA Zone 5, this bushy perennial stands at 1 to 3 feet in height and boasts small blue-violet flowers on spikes, complemented by blue-green needle-like foliage. The essential oils found in its flowers give lavender its distinctive balsam-like scent.
Named “English” lavender due to its prolific growth in the English climate, this plant thrives in sunny conditions with well-drained soil, showing resilience to various soil types. Its presence not only enhances the aesthetics of gardens but also attracts bees, butterflies, and other pollinators. Consider planting lavender along walkways or near seating areas to enjoy both its visual appeal and aromatic benefits.
Interesting Science Videos
Taxonomic Classification of Lavender (Lavandula angustifolia)
| Taxonomic Rank | Classification |
| Kingdom | Plantae |
| Phylum | Magnoliophyta |
| Class | Magnoliopsida |
| Subclass | Asteridae |
| Order | Lamiales |
| Family | Lamiaceae |
| Genus | Lavandula |
| Species | Lavandula angustifolia |
Habitat and Distribution of Lavender
- Lavender, particularly the English lavender (Lavandula angustifolia), is native to the Mediterranean region.
- It thrives in its native environment, which typically consists of rocky soil and grassy, hilly meadows.
- English lavender is suitable for U.S. Department of Agriculture (USDA) plant hardiness zones 5 through 9, indicating a wide range of climates it can adapt to.
- In its natural habitat, lavender grows well in sandy and poor soils, often found in dry, chalky, and rocky conditions.
- It is well-suited for areas with good drainage and can tolerate windswept locations and even salt-laden air.
- Despite the name “English lavender,” it is not native to England. However, it does adapt well to the English climate, particularly compared to other lavender species like Spanish lavender (Lavandula stoechas).
- Excessively wet soil is not conducive to the growth of English lavender.
- Lavender, in general, thrives in full sun conditions, requiring at least 8 hours of sunlight per day.
- Lavandula Angustifolia varieties, such as Hidcote, Munstead, Lady, and Sachet, are well-suited for cooler climates. These varieties flourish in regions with milder temperatures.
- Thus lavender’s habitat and distribution are diverse, with adaptations to different climates, soil types, and sunlight conditions, making it a versatile and widely cultivated herb.
Anatomy and Morphology of Lavender Plant
- Lavender boasts a taproot system, characterized by a central main root and branching structures. This woody root system provides stability, anchoring the plant securely. The plant’s preference for well-draining soil reflects its sensitivity to excessive moisture.
- The plant exhibits square, branching stems, a distinctive feature typical of the Lamiaceae family. Cloaked in narrow, elliptical leaves, these stems support the overall structure of the lavender plant. The leaves, adorned with a silvery-green hue and fine hairs, serve protective functions against both moisture loss and potential herbivorous threats.
- Lavender’s inflorescence comprises sequential flower spikes. Each spike houses numerous buds that bloom successively, creating a visually striking display. The vibrant flowers range in color from soft purples to deep violets and are the primary source of the plant’s precious essential oils, known for their aromatherapeutic and medicinal properties.
- Surrounding each lavender bud is a tubular calyx, a protective structure that encases the developing flower. Even after the bloom, the calyx remains intact, contributing to the plant’s distinctive appearance and rustic allure.
- Within the opened bud, the lavender flower reveals whorls of petals forming the corolla. Delicate shades of lilac, pink, or white petals create a visually appealing display. Apart from their aesthetic value, these petals play a crucial role in attracting pollinators such as bees and butterflies, facilitating the plant’s reproduction.
- Lavender is a monoecious plant, hosting both male and female flowers on the same individual. The flowers are perfect, containing both male (stamen) and female (carpels) reproductive organs. Pollen produced in the stamen fertilizes ovules in the carpel, leading to the development of seeds.
How to Care and Grow Lavender
Growing and caring for lavender requires attention to specific conditions and practices. Here’s a guide on how to cultivate lavender effectively:
- Light: Lavender thrives in full sunlight, ensuring abundant buds and robust bushes. Providing a sunny location for your lavender plants is crucial for their optimal growth.
- Soil: Lean soil, without excessive organic matter, encourages higher oil concentration and pleasant fragrances in lavender. Well-drained, slightly dry soil is preferred, and incorporating sand into traditional potting mixes enhances drainage. An alkaline or chalky soil enhances fragrance, while a pH below 6.5 may shorten the lifespan of lavender.
- Water: Lavender is drought-tolerant once established. During the first growing season, regular watering is essential. However, excessive water can lead to fungal diseases and root rot. Once established, lavender can withstand extended periods of drought.
- Temperature and Humidity: Lavender is resilient to a range of temperatures, with dampness, especially in high humidity, posing a greater threat than cold. Adequate spacing for airflow and planting in sunny locations help combat humidity-related issues. Protect plants from harsh winter winds by planting near a stone or brick wall.
- Fertilizer: Lavender requires minimal fertilization. Adding compost during planting is beneficial, but ongoing feeding is unnecessary. Over-fertilization may compromise the potency of lavender.
- Pruning: Regular pruning through flower harvesting is essential. Spring pruning maintains plant shape and encourages new growth. Taller varieties can be cut back by about one-third, while lower-growing ones can be pruned a few inches or cut down to new growth.
- Harvesting: Lavender flowers maintain their fragrance when dried. Harvest buds as they begin to open and hang them upside-down in a warm, well-ventilated space. Lavender flowers are not only aromatic but also edible, suitable for salads, soups, stews, seasoning, baking, and tea.
- Soil Preparation: Lavender thrives in hot, dry climates with full sun, good air circulation, and fast-draining, alkaline soil. The plant prefers low-nutrient soils and is particularly suited to arid climates, such as those found west of the Mississippi.
- Mulching: In dry climates, a 1-2 inch layer of small crushed gravel is recommended for mulching. Coarse-textured mulches like pine needles and crushed nutshells are suitable. Avoid water-retentive mulch materials, keeping the crown dry for healthier plants.
- Watering: Lavender, once established, prefers dry growing conditions. Regular irrigation during the first growing season is necessary, transitioning to less frequent, deep watering in subsequent years to encourage deep root development.
- Pruning Established Plants: Prune lavender in spring when signs of new growth appear. Limit pruning to no more than one-third of old stems to rejuvenate the plant. Wait until mid-spring to prune winter-damaged branches, promoting round, mounded plant shapes.
How to Propagate Lavender
Softwood Cuttings
- Softwood cuttings involve the use of young, flexible shoots from the lavender plant.
- These cuttings are typically taken in the spring when new growth is emerging.
- Choose segments around 6-8 inches long, ensuring they have a healthy set of leaves.
- Plant the cuttings in individual containers after they have rooted, providing a well-draining soil mix.
Hardwood Cuttings
- Hardwood cuttings are taken from more mature sections of the plant later in the growing season, usually from mid-summer to fall.
- These cuttings have woody stems and require a longer time for root development.
- They are well-suited for overwintering as the roots establish themselves.
Layering
- Layering is a technique where you gently bend living plant branches towards the ground.
- The selected branch is covered with soil, encouraging root growth from leaf nodes in contact with the soil.
- This method is particularly useful for branches with young shoots, and consistent soil moisture is crucial for success.
Best Time for Propagation
- Spring is the prime time for methods involving softwood or semi-hardwood, ensuring optimal conditions for rooting.
- Late summer to fall is preferable for more mature material, allowing time for root development before winter.
Potting and Repotting Lavender
- Propagating lavender in pots provides flexibility, especially for gardeners with limited outdoor space or in regions with challenging climates.
- Select pots with good drainage to prevent waterlogged soil, which can lead to root rot.
- Opt for a pot that accommodates the root ball with a few inches to spare, avoiding excessive space that may retain moisture.
- Plant lavender in a loose, soilless mix suitable for containers, ensuring it drains well.
- Water the potted lavender when the top layer of soil appears dry, avoiding excessive moisture on the foliage.
- Transplant the lavender outdoors or into larger pots as needed, providing ample sunlight for healthy growth.
Chemical Composition and Active Components of Lavender
| Active Compounds | Chemical Classification | Uses |
| Linalool | Monoterpene alcohol | Aromatherapy, anxiolytic, sedative |
| Linalyl Acetate | Ester | Aromatherapy, anti-inflammatory |
| Terpinene-4-ol | Monoterpene alcohol | Antimicrobial, anti-inflammatory |
| Lavandulyl Acetate | Ester | Aromatherapy, anti-inflammatory |
| Lavandulol | Monoterpene alcohol | Aromatherapy, potential anti-inflammatory |
| Eucalyptol (1,8-cineol) | Oxide | Respiratory aid, anti-inflammatory |
| Camphor | Ketone | Topical analgesic, anti-inflammatory |
| Borneol | Monoterpene alcohol | Aromatherapy, potential anti-inflammatory |
| 4-Terpineol | Monoterpene alcohol | Antimicrobial, potential anti-inflammatory |
| Nerol | Monoterpene alcohol | Aromatherapy, potential antimicrobial |
| Geraniol | Monoterpene alcohol | Fragrance, potential anti-inflammatory |
| Ocimene | Monoterpene | Aromatherapy, potential antimicrobial |
| Pinene | Monoterpene | Respiratory aid, potential anti-inflammatory |
| Limonene | Monoterpene | Fragrance, potential anti-inflammatory |
| Coumarin | Benzopyrone | Fragrance, potential anti-inflammatory |
| Cineole (Eucalyptol) | Oxide | Respiratory aid, anti-inflammatory |
| Caryophyllene | Sesquiterpene | Anti-inflammatory, potential analgesic |
| Myrcene | Monoterpene | Potential sedative, antimicrobial |
| Terpinolene | Monoterpene | Antimicrobial, potential antioxidant |
| Pulegone | Ketone | Potential insect repellent |
| B-Pinene | Monoterpene | Respiratory aid, potential anti-inflammatory |
| Bornyl Acetate | Ester | Aromatherapy, potential anti-inflammatory |
| Geranyl Acetate | Ester | Fragrance, potential anti-inflammatory |
Benefits/Uses of Lavender Plant
Lavender emerges as a versatile wellness enhancer, showcasing its prowess across skincare, aromatherapy, medicinal uses, culinary delights, and spiritual practices. Its diverse applications, coupled with its rich biological marvels, position lavender as a holistic gem for overall well-being. From skin rejuvenation to stress relief and beyond, lavender offers a myriad of benefits for a wholesome lifestyle.
Lavender in Skincare
- Skin Rejuvenation: Lavender’s antimicrobial and antioxidant properties actively cleanse and hydrate the skin, promoting a vibrant and healthy complexion. The natural compounds in lavender play a crucial role in neutralizing bacteria and excess oil, contributing to clearer skin.
- Youthful Skin: The improved circulation induced by lavender provides skin cells with much-needed oxygen, energizing them for the regeneration of new cells. This cellular renewal imparts a healthy and youthful glow to the skin. Wrinkles, often indicative of aging, are visibly reduced as lavender plumps up the skin.
- Dry Skin Harmony: Lavender acts as a balancer, equalizing the skin’s pH levels and providing moisture. Its oil control properties result in supple and healthy-looking skin, eliminating dry or flaky patches.
- Anti-Inflammatory Magic: Lavender’s antibacterial and anti-inflammatory characteristics combat bacteria, cleansing pores and calming the skin. This proves effective against acne and other irritations, with reported benefits in minimizing the appearance of scars. By reducing redness and inflammation, lavender facilitates an environment conducive to the formation of new, healthy skin cells.
- Antioxidant Shield: Lavender, enriched with antioxidants, plays a pivotal role in improving skin texture. By scavenging free radicals responsible for dull and dehydrated skin, lavender helps in shedding dead skin cells and fostering the generation of a robust skin barrier. Additionally, its antimicrobial activity positions lavender as a potential natural preservative in skincare products.
- Blemish Treatment: Lavender exhibits promise in dermatological applications, potentially aiding in the treatment of acne, eczema, and skin inflammation. Its antioxidant activity contributes to wound healing, showcasing a multifaceted approach to skincare.
Aromatherapy and Stress Relief
- Soothing Sleep: Lavender’s aromatic essence, incorporated into nighttime skincare products, contributes to a calming effect, aiding in achieving a relaxed state and promoting quality sleep. Scientific studies indicate a significant sleep-promoting impact, enhancing sleep by up to 20%.
- Mood Enhancement: Lavender’s positive effects on mood, stress, anxiety, and depression are substantiated by research findings. It stands as a natural mood booster with holistic well-being implications.
While lavender itself doesn’t induce immediate sleep, it serves as a catalyst for relaxation. By calming the mind and body, lavender creates an environment conducive to falling asleep naturally.
Medicinal and Therapeutic Magic
- Insomnia Alleviation: Lavender’s potential in improving sleep quality is showcased in studies involving intensive care unit (ICU) patients. Its effectiveness in alleviating sleep difficulties is particularly noteworthy.
- Pain Relief: The anti-inflammatory components present in lavender offer relief from various types of pain, making it a potential alternative to traditional pain relievers.
- Blood Pressure Regulation: Preliminary studies suggest that inhaling diluted lavender essential oil may have a positive impact on blood pressure and heart rate, though further research is required for conclusive evidence.
- Asthma Support: Lavender’s anti-inflammatory effects, demonstrated in studies on mice, raise intriguing possibilities for its potential in improving bronchial asthma. Human studies are needed for a comprehensive understanding.
- Menopausal Comfort: Lavender aromatherapy emerges as a potential non-pharmacological intervention for reducing menopausal hot flashes, contributing to an improved quality of life.
- Antifungal Warrior: Studies highlight lavender’s potential antifungal activity, making it a candidate for treating conditions like athlete’s foot and ringworm.
Culinary Delights
- Edible Lavender: Certain lavender varieties, such as English lavender, prove edible and enhance culinary creations. From lavender-infused cookies to cakes, its subtle floral flavor adds a unique and delightful dimension to culinary delights.
Spiritual Significance
- Protection and Purification: Lavender has a rich history in spiritual practices, believed to possess protective properties against negative energy and influences. Whether through essential oil diffusion, smudging rituals, sachets, baths, or floor washes, lavender creates a protective energy, establishing a barrier against negativity.
Biological Significance
- Antibacterial Properties: Lavender’s antibacterial properties extend beyond skincare, serving as a cleansing agent.
- Antifungal Ally: Research suggests lavender’s potential in inhibiting the growth of certain fungi, showcasing its multifaceted biological benefits.
Miscellaneous Uses
- Versatile Applications: Lavender’s versatility goes beyond skincare, extending to crafting oils, sachets, and natural cleaning. Its ability to act as an air freshener and neutralize odors adds to its myriad applications.
Side Effects of Lavender
- Lavender, when consumed as part of foods or medicine, is generally considered safe. Possible side effects include infrequent occurrences of constipation, diarrhea, and headaches.
- Lavender is typically well-tolerated when applied to the skin. Instances of skin irritation are rare but can occur; it is recommended to perform a patch test before extensive use.
- Lavender essential oil, used in aromatherapy for up to 12 weeks, is generally safe. Direct ingestion of essential oils, especially when mixed with food or drinks, is cautioned against due to potential oral mucosa irritation.
- Ingesting lavender essential oils directly may lead to irritation of the oral mucosa, affecting the soft palate, throat, and tongue.
- Additional side effects encompass constipation, headaches, increased appetite, and skin rash, particularly with topical use.
- Self-medicating with lavender is discouraged, and consultation with a healthcare professional is recommended.
- Topical use of lavender may trigger allergic reactions in some individuals.
- A study has suggested a potential link between lavender-containing products and premature breast development in children, warranting caution.
- Limited information on lavender oil safety during pregnancy underscores the importance of consulting a healthcare provider.
- Caution is advised against combining lavender oil with sleep-inducing drugs (benzodiazepines, barbiturates).
- Attention is needed when using lavender oil alongside medications that reduce blood pressure (captopril, enalapril).
- Potential interactions with ongoing medications, including those in Ayurvedic preparations, necessitate adherence to advice from Ayurvedic physicians.
- Full disclosure of all medications during consultations is crucial for an informed approach.
Pest/Disease on Lavender
| Pest/Disease | Description (Cause, Symptoms) | Prevention |
| Root Rot | Caused by fungi in poorly-drained soils, especially when lavender is overwatered. Symptoms include wilting and yellowing. | – Plant lavender in full sun and well-drained soil. – Avoid overwatering; lavender thrives with minimal watering. |
| Botrytis | Fungal disease causing grey foliage at the base, prevalent in high humidity. Leaves yellow, wilt, and die. | – Ensure proper spacing for air circulation. – Remove infected leaves. – Use fungicides to prevent spreading. |
| Septoria Leaf Spot | Fungus thriving in humid conditions, leading to grey spots on leaves. Can stunt growth. | – Keep leaves dry, avoid crowding. – Prune interior branches for airflow. – Remove infected leaves. – Use organic fungicides. |
| Alfalfa Mosaic Disease | Viral disease transmitted by aphids or contaminated tools. No cure, highly contagious. | – Sanitize tools thoroughly. – Wear gloves. – Monitor for pests like aphids. – Uproot infected plants immediately. Dispose properly. |
| Shab | Wind-spread fungal disease affecting stems and branches. Green turns brown with black spots. | – Purchase disease-free stock. – Avoid taking cuttings from diseased plants. – Uproot and dispose of infected plants. |
| Moles and Voles | Moles tunnel and uproot, voles eat roots. | – Use traps (identify the pest correctly). – Consider adopting a cat or dog as a deterrent. |
| Fire Ants | Nests under lavender, causing plant collapse. | – Soak soil to discourage nesting. – Use fire ant-specific insecticides. – Spread diatomaceous earth. |
| Spittlebugs | Harmless foam-producing nymphs, may lead to Xylella bacterial disease. | – Monitor but don’t necessarily remove. – Hand removal if necessary. |
| Whiteflies | Sap-sucking insects on leaf undersides, secrete honeydew. | – Apply neem oil. – Plant companion plants to attract predators. – Remove by hand. |
| Powdery Mildew | Fungal disease causing white powdery spots on leaves. Leads to wilting and yellowing. | – Provide good air circulation. – Avoid overhead watering. – Use fungicidal sprays if necessary. |
| Scale Insects | Tiny insects that attach to stems and leaves, sucking sap. Can cause yellowing and wilting. | – Introduce natural predators like ladybugs. – Prune and dispose of heavily infested branches. – Use horticultural oil. |
| Aphids | Small, soft-bodied insects that feed on plant sap. Can lead to yellowing and curling of leaves. | – Introduce natural predators like ladybugs and lacewings. – Spray insecticidal soap or neem oil. – Remove aphids by hand. |
| Downy Mildew | Fungal disease causing grayish-purple patches on leaves. Leads to wilting and stunted growth. | – Plant in well-drained soil. – Avoid overhead watering. – Space plants for proper air circulation. – Use fungicidal sprays. |
| General Lavender Care Tips | ||
| Planting Conditions | – Full sun for dry leaves and interiors. | – Choose a sunny location for planting. |
| Soil Drainage | – Well-drained soil; lavender dislikes waterlogged conditions. | – Improve drainage with sand or gravel in heavy clay soil. |
| Watering Habits | – Minimal watering; avoid overwatering. | – Do not use mulch for water retention. – Water sparingly, especially during dry periods. |
| Air Circulation | – Avoid crowding with other plants. | – Maintain proper spacing for air circulation. |
Lavender Products
- Lavender Essential Oil: Promotes relaxation and stress relief. Used in skincare for various benefits.
- Hand Sanitizer: Antibacterial – cleans hands with a soothing lavender scent.
- Lavender Scented Soap: Provides a calming and aromatic shower experience.
- Lavender Shampoo and Conditioner: Cleanses and conditions hair with a lavender fragrance.
- Lavender Body Lotion: Nourishes and hydrates the skin, leaving a subtle lavender scent.
- Lavender Pillow Mist: Spritzed on pillows for a calming effect before sleep.
- Lavender Sleep Mask: Facilitates relaxation during sleep.
- Lavender Scented Drawer Liners: Adds a subtle lavender aroma to clothing.
- Lavender Bath Bombs: Creates a calming and aromatic bath experience.
- Lavender-Infused Gummies or Edibles: Consumable for potential relaxation benefits.
- Lavender Scented Candles: Provides a calming atmosphere and pleasant fragrance.
- Lavender Reed Diffusers: Keeps living spaces consistently fragrant.
- Lavender Foot Cream: Moisturizes and relaxes tired feet.
- Lavender-Infused Room Spray: Instantly freshens up the room with a lavender scent.
Interesting and Cool Facts of Lavender Plant
- The term ‘lavender’ finds its roots in the Latin word ‘lavare,’ meaning to wash. Lavender boasts not only a delightful fragrance and aesthetic appeal but also a multitude of medicinal, culinary, and spiritual uses.
- Lavender’s aromatic profile, rich with camphorous elements, acts as a natural repellent for pests like mice, flies, and mosquitoes.
- Lavender flowers hold spiritual significance, symbolizing purity, silence, devotion, serenity, grace, and calmness. Traditionally, they were hung above doors to ward off evil spirits.
- Egyptians utilized lavender oil during mummification to preserve organs and impart a sweet fragrance.
- In 17th-century London, lavender bunches were attached to clothes during the Great Plague as a protective measure.
- Lavender played a role in Four Thieves Vinegar, used by grave-robbers for disease prevention during body theft.
- French glove makers scented gloves with lavender in the 16th century to resist cholera.
- Historical figures like Elizabeth I, Charles VI of France, Louis XIV, and Queen Victoria embraced lavender for various purposes, from consuming lavender conserve to bathing in lavender water.
- Lavender has a rich history, from its use in ancient Egyptian mummification to treating insomnia in ancient Greece.
- The Shakers were pioneers in successful lavender cultivation, establishing lavender farms and contributing to the global herb market.
- Lavender’s color is the origin of its name, Lavandula angustifolia, commonly known as English lavender.
- Lavender serves as an effective bug repellent and can protect other plants from pests.
- This resilient plant thrives in neglect and can adapt to poor soil conditions.
- Lavender belongs to the mint family and holds symbolic meanings like purity, devotion, and calmness.
- Bridestowe Lavender Estate in Tasmania is the world’s largest privately-owned lavender farm.
- Lavender has over 45 species and 450 varieties, continuously expanding.
- Lavender nectar produces high-quality honey, disliked by mosquitoes.
- In the language of flowers, lavender signifies devotion, luck, success, happiness, purity, serenity, grace, and calmness.
- Lavender propagation is done by cutting woody bits and planting them, as it doesn’t grow from seeds.
- Lavender tea is gaining popularity, and EEG studies show its inhalation promotes brainwave patterns associated with relaxation.
Lavender Famous Varieties
| Lavender Type | Special Characteristics | Popular Varieties |
| Spanish Lavender | Silvery-toned leaves, larger pine-cone shaped flowers, “rabbit’s ears” appearance, drought-hardy | Lavandula stoechas |
| English Lavender | Tight purple (or blue, violet, white, or pink) flower spikes, classic “true lavender,” aromatic grayish-green foliage | Lavandula angustifolia |
| Lavandin Hybrids | Ultra-high essential oil content, vigorous and disease-resistant, aromatic sage-colored foliage | ‘Provence,’ ‘Grosso’ |
| French Lavender | Toothed needle-shaped leaves, “fluffier” flowers, subtle fragrance, suited to mild climates | Lavandula dentata |
| Portuguese Lavender | Long stems, lilac-colored classic-shaped flowers, strong pungent smell, national flower of Portugal | Lavandula latifolia |
References
- https://southerngracelavenderfarm.com/botanical-overview
- https://thelavenderland.blogspot.com/2017/09/lavender-plant-anatomy-and-morphology.html
- https://www.hopesgrovenurseries.co.uk/knowledge-base/pests-diseases-and-common-problems-with-lavender/
- https://www.theplantcompany.co.nz/expert-advice/lavender/lavender-hedge-problems-disease/lavender-disease-pest#
- https://originalbotanica.com/blog/spiritual-benefits-lavender-magic#
- Kajjari S, Joshi RS, Hugar SM, Gokhale N, Meharwade P, Uppin C. The Effects of Lavender Essential Oil and its Clinical Implications in Dentistry: A Review. Int J Clin Pediatr Dent. 2022 May-Jun;15(3):385-388. doi: 10.5005/jp-journals-10005-2378. PMID: 35991803; PMCID: PMC9357533.
- https://www.everydayhealth.com/diet/what-are-possible-benefits-lavender-must-know-facts-about-therapeutic-plant/
- https://www.epicgardening.com/lavender-varieties/
