Lavender (Lavandula spp.) is a well-known and fragrant perennial plant that will come back every year with gray-green foliage, upright flower spikes, and a compact shrub form. Planting lavender is best in the spring after the risk of frost has passed and the soil has warmed up.
I. Appearance and Characteristics
Lavandula (common name lavender) is a genus of 47 known species of perennial flowering plants in the mints family, Lamiaceae. It is native to the Old World, primarily found across the drier, warmer regions of mainland Eurasia, with an affinity for maritime breezes.
Lavender is found on the Iberian Peninsula and around the entirety of the Mediterranean coastline (including the Adriatic coast, the Balkans, the Levant, and coastal North Africa), in parts of Eastern and Southern Africa and the Middle East, as well as in South Asia and on the Indian subcontinent.
The English word lavender came into use in the 13th century, and is generally thought to derive from Old French lavandre, ultimately from Latin lavare from lavo (to wash), referring to the use of blue infusions of the plants. The botanic name Lavandula as used by Linnaeus is considered to be derived from this and other European vernacular names for the plants.
The names widely used for some of the species, “English lavender”, “French lavender” and “Spanish lavender” are all imprecisely applied. “English lavender” is commonly used for L. angustifolia, though some references say the proper term is “Old English lavender”. The name “French lavender” may refer to either L. stoechas or to L. dentata. “Spanish lavender” may refer to L. stoechas, L. lanata, or L. dentata.
Plant and leaves
The genus includes annual or short-lived herbaceous perennial plants, and shrub-like perennials, subshrubs or small shrubs.
Leaf shape is diverse across the genus. They are simple in some commonly cultivated species; in other species, they are pinnately toothed, or pinnate, sometimes multiple pinnate and dissected. In most species, the leaves are covered in fine hairs or indumentum, which normally contain essential oils.
Flowers
Flowers are contained in whorls, held on spikes rising above the foliage, the spikes being branched in some species. Some species produce colored bracts at the tips of the inflorescences. The flowers may be blue, violet, or lilac in the wild species, occasionally blackish purple or yellowish. The sepal calyx is tubular. The corolla is also tubular, usually with five lobes (the upper lip often cleft, and the lower lip has two clefts).
II. Types of Lavender
There are many varieties of lavender, each boasting benefits and perks. Some of the most popular include:
- English Lavender (Lavandula angustifolia): A varietal that’s available in several cultivars, including: ‘Munstead,’ an old-fashioned standard with blue-purple flowers; ‘Hidcote,’ a version favored for its dark purple flowers; ‘Jean Davis,’ a unique blend that produces pale pink flower spikes.
- Lavandin (Lavandula x intermedia): A variety with several cultivars including: ‘Provence,’ which is particularly popular for drying; ‘Grosso,’ a highly disease-resistant and fragrant standard.
- Fringed lavender(Lavandula dentata): A bushy, spreading shrub varietal that produces dense purple-blue flower spikes that are only mildly fragrant.
- (Lavandula stoechas) French lavender: A beautiful Mediterranean varietal that is compact and bushy with fragrant, dark purple flowers.
II. How to Grow and Care
Sunlight
Lavender plants grown in full sunlight is the best way to guarantee a lot of buds and big, full bushes.
Temperature and Humidity
Lavender can withstand a range of temperatures, and it’s usually dampness more than the cold that’s responsible for killing lavender plants. Dampness can come in the form of wet roots during the winter months or high humidity in the summer. If humidity is a problem, make sure you have plenty of space between your plants for airflow, and always plant your bushes in a sunny location.
Protect lavender plants from harsh winter winds by planting them next to a stone or brick wall to provide additional heat and protection. If you live in an area where the ground routinely freezes and thaws throughout the winter, your lavender plants will benefit from a layer of mulch applied after the ground initially freezes to protect the roots.
Watering
Lavender is a resilient plant that is extremely drought-tolerant once established. When first starting your lavender plants, keep them regularly watered during their first growing season. After that, they can handle extended periods of drought—in fact, too much water can lead to fungal disease and root rot.
Soil
Lean soil (soil without a lot of organic matter mixed in) will encourage a higher concentration of oils (and good smells), so go easy on the organic matter and fertilizer. Lavender plants prefer well-drained soil that is on the drier side, so if you’re using a traditional potting mix, be sure to add in some sand for drainage. An alkaline or especially chalky soil will enhance your lavender’s fragrance, while any pH below about 6.5 will likely cause lavender plants to be very short-lived.
Fertilizing
It’s a good idea to add a handful of compost into the hole when you are first starting lavender plants. Beyond that, feeding is not needed with these plants and can detract from the overall potency of your lavender.
Pruning
Although lavender plants get regularly pruned simply by harvesting the flowers, a bit of spring pruning is recommended to keep your plant well-shaped and to encourage new growth. Taller lavender varieties can be cut back by approximately one-third of their height, while lower-growing varieties can either be pruned back by a couple of inches or cut down to new growth.
If you live in an area where lavender suffers winter die-back, don’t prune your plants until you see new green growth at the base of the plant. If you disturb the plants too soon in the season, they’re unlikely to develop new growth.
Propagation
Lavender plants are best propagated by either softwood cuttings (the soft, flexible tips of shoots) or hardwood cuttings (segments of shoots with woody stems). Softwood cuttings are available in the spring; hardwood cuttings are available in the fall. Both processes can be done relatively the same—here’s how:
- Use a sterilized, sharp knife to cut a 3-inch segment of a healthy shoot from the plant. Hardwood cuttings should be severed just below a bump that identifies a leaf node. Remove the leaves from the bottom 2 inches of the stem and scrape off the skin from the bottom of the stem along one side.
- Fill a small pot with a seed-starting mix that has been moistened with a bit of water.
- Dip the stripped side of the cutting in rooting hormone. Bury it into the seed-starting mix.
- Cover the pot with plastic and place somewhere warm with ample filtered light. Softwood cuttings take two to four weeks to begin rooting; hardwood cuttings take a bit longer.
- When you’ve noticed that roots are established, remove the plastic covering and place the pot back in a sunny location.
- Feed the plant once a week with a liquid plant fertilizer diluted to 25 percent strength.
- After two or three weeks, the plant can be transplanted outdoors or into a larger pot with standard potting soil—commercial potting soil has enough nutrients to nourish the plant without any more feeding.
Potting and Repotting
Where outdoor planting is not practical, growing lavender in a ceramic, clay, or terra-cotta pot and moving it around to follow the sun or even bringing it indoors for the winter, will be most efficient. Lavender prefers to grow in a tight space. A pot that can accommodate the root ball with a couple of inches to spare is a good choice; a pot that is too large will encourage excessive dampness.
Ensure that your container has plenty of holes at its base for drainage—root rot is one of the few problems experienced by lavender plants. Additionally, you can plant lavender in a clay or terracotta pot to help wick moisture away from the soil and keep it from getting too wet. Use a loose, soilless mix for planting, and remember that container-grown lavender will require more water than garden-grown plants. A good rule of thumb is to water when the soil (not the plant) appears dry, watering at the base of the plant to limit dampness on the foliage.
Pests and Diseases
Common Pests & Plant Diseases
Lavender plants are not afflicted by many diseases. They may develop phytophthora, which is a soil-borne fungal disease that causes root and stem rot. Lavender can also succumb to septoria leaf spot, which is caused by a fungus and is also commonly found on tomato plants.
However, many common pests are attracted to lavender, including whiteflies, spider mites, leafhoppers, and spittlebugs (which do little damage). Water spray, insecticidal soaps, and neem oil can be helpful to eliminate pests. The four-lined plant bug (FLPB) is another pest that can be found sucking on lavender plant leaves and can be controlled by pesticides.
Common Problems
Lavender plants are fairly trouble-free, but problems can occur. Here are common issues you may encounter when growing lavender indoors or outdoors.
Leaves Turning Yellow
Leaves turn yellow if the soil is too wet. If the lower leaves are yellow, that definitely means you are overwatering the plant. Many lavender plants will perish if their soil gets too wet over the winter months.
Plant Smells Bad
You have probably overwatered your lavender plant. The plant may have root rot. If you have a potted lavender plant that you think has root rot, prune the dead or affected roots with a sharp and sterilized cutting tool and repot the plant to see if it’s salvageable.
Drooping Leaves
You have probably underwatered your lavender plant. In addition, the soil will feel parched.
Soil Is Always Wet
You have overwatered your lavender plant. See if you can remove any root rot and replant the lavender in new soil.
IV. Uses and Benefits
- Ornamental uses
Many members of the genus are cultivated extensively in temperate climates as ornamental plants for garden and landscape use.
- Medicinal uses
The German scientific committee on traditional medicine, Commission E, reported uses of lavender flower in practices of herbalism, including its use for restlessness or insomnia, Roemheld syndrome, intestinal discomfort, and cardiovascular diseases, among others.
- Culinary uses
Culinary lavender is usually English lavender, the most commonly used species in cooking (L. angustifolia ‘Munstead’). As an aromatic, it has a sweet fragrance with lemon or citrus notes. It is used as a spice or condiment in pastas, salads and dressings, and desserts. Their buds and greens are used in teas, and their buds, processed by bees, are the essential ingredient of monofloral honey.
Use of buds
For most cooking applications the dried buds, which are also referred to as flowers, are used. Lavender greens have a more subtle flavor when compared to rosemary.
The potency of the lavender flowers increases with drying which necessitates more sparing use to avoid a heavy, soapy aftertaste. Chefs note to reduce by two-thirds the dry amount in recipes that call for fresh lavender buds.
Lavender buds can amplify both sweet and savory flavors in dishes and are sometimes paired with sheep’s milk and goat’s milk cheeses. Lavender flowers are occasionally blended with black, green, or herbal teas. Lavender flavors baked goods and desserts, pairing especially well with chocolate. In the United States, both lavender syrup and dried lavender buds are used to make lavender scones and marshmallows.
Lavender buds are put into sugar for two weeks to allow the essential oils and fragrance to transfer; then the sugar itself is used in baking. Lavender can be used in breads where recipes call for rosemary. Lavender can be used decoratively in dishes or spirits, or as a decorative and aromatic in a glass of champagne. Lavender is used in savory dishes, giving stews and reduced sauces aromatic flair. It is also used to scent flans, custards, and sorbets.
In honey
The flowers yield abundant nectar, from which bees make a high-quality honey. Monofloral honey is produced primarily around the Mediterranean Sea, and is marketed worldwide as a premium product. Flowers can be candied and are sometimes used as cake decorations. It is also used to make “lavender sugar”.
- Cosmetic uses
Commercially, the plant is grown mainly for the production of lavender essential oil. English lavender (Lavandula angustifolia) yields an oil with sweet overtones and can be used in balms, salves, perfumes, cosmetics, and topical applications. Lavandula × intermedia, also known as lavandin or Dutch lavender, hybrids of L. angustifolia and L. latifolia. are widely cultivated for commercial use since their flowers tend to be bigger than those of English lavender and the plants tend to be easier to harvest. They yield a similar essential oil, but with higher levels of terpenes including camphor, which add a sharper overtone to the fragrance, regarded by some as of lower quality than that of English lavender.
The US Food and Drug Administration considers lavender as generally recognized as safe (GRAS) for human consumption. The essential oil was used in hospitals during World War I.
- Other uses
Flower spikes are used for dried flower arrangements. The fragrant, pale purple flowers and flower buds are used in potpourris. Lavender is also used as herbal filler inside sachets used to freshen linens. Dried and sealed in pouches, lavender flowers are placed among stored items of clothing to give a fresh fragrance and to deter moths. Dried lavender flowers may be used for wedding confetti. Lavender is also used in scented waters, soaps, and sachets.
V. Harvesting and Storage
A major reason lavender is so prized is that its flowers keep their fragrance once dried. For best drying results, harvest the flowers as the buds first begin to open. Hang them in small bunches upside-down in a warm spot with good air circulation until dried.
Aside from being beautiful and aromatic, lavender flowers are also edible. They can be used raw in salads, added to soups and stews, used as a seasoning, baked into cookies, and brewed into tea. Use sparingly; a little lavender flavor goes a long way.
