Lavender Variety Introduction
Today's focus is to introduce you to common knowledge about flower cultivation, focusing on lavender, and introducing the varieties of lavender. Let me introduce them to you.
For a year, I have been fascinated with herbs, and recently I have become even more absorbed in them. However, even so, I have always been unable to distinguish between the various types of herbs, especially the lavender with various names. How are they classified? Many of the information sources I've found differ in their descriptions. I previously saw in You Cixiong's book that lavender can be divided into five varieties based on leaf shape: pinnate, toothed, narrow, broad, and hybrid. Later, I found some information online that also divided them into five categories. After compiling other detailed information and pictures, I finally have some clues, summarized as follows——
Lavender (Lavandula), a plant of the Lamiaceae family, is native to regions with low rainfall along the Mediterranean coast. Most commonly cultivated species come from southern Europe and the Mediterranean area, and they are also distributed in the Canary Islands in the north Atlantic, North Africa, southwest Asia, the Arabian Peninsula, and India.
The origin of the name Lavandula may be related to its use by ancient people to make scented bathwater. The Latin word 'Lavare' in its name means 'to wash'. Today, various brands of soap, detergents, and many perfumes containing lavender essential oil are still very popular and widely used.
1. French Lavender Series Stoechas
Native to southern France, its flower spike shape is different from other types of lavender. Each layer of small flowers has a broad bract on the outside, and they are densely stacked together, with a total length of about 3-5 cm. The top has several bracts shaped like rabbit ears, growing on nearly round to oval flower spikes. Most varieties have purple-red flowers, and a few are yellow-green, such as green lavender (L. viridis). The height of the plant is about 20 to 45 cm.
1-1. French Lavender (L.stoechas)
Also known as Spanish lavender, it has similar growth habits to narrow-leaf lavender. Attention should be paid to shading and moisture removal in hot summers. French lavender is suitable for home viewing and as a culinary seasoning. The extracted essential oil quality is not as good as that of narrow-leaf lavender. French lavender (L.stoechas) is easy to identify because it has brightly colored bracts on the top of its inflorescence, which people vividly call 'rabbit ears'. This is a complex group, and it is difficult to distinguish between many subspecies. Fortunately, two widely cultivated subspecies are easy to identify: one is common French lavender (L.stoechas subsp stoechas), which has shorter flower stems and relatively smaller bracts, often with a deep purple color; the other is butterfly lavender (L. stoechas subsp pedunculata), which has longer flower stems and longer bracts. Both of these French lavender subspecies won the Royal Horticultural Society's Award of Garden Merit (AGM) in 1993. They both bloom in May, earlier than other lavenders. Other subspecies of French lavender (L.stoechas) are less commonly used. L. stoechas subsp. sampaioana from Portugal and L. stoechas subsp. cariensis from Turkey were also included in this trial, and under the same cultivation conditions, they showed differences from other lavenders. These two subspecies are suitable for planting in relatively shaded environments.
1-2. Green Lavender (L.viridis)
Also known as aromatic leaf lavender, its leaves have a strong fragrance, and it blooms with white flowers. The top of the inflorescence has green bracts, which are also included in the French lavender category. This species is not cold-resistant and needs to be overwintered in protected facilities. In this Wisley cultivation trial, it was frozen to death when planted in the field. Recently, a new series of hybrid lavender varieties has been bred by crossing green lavender (L.viridis) with French lavender (L.stoechas). Many of these hybrid varieties were included in this trial, and the best-performing one is 'Willow Vale' (Willow Vale) (L.viridis x L. stoechas subsp pedunculata), which blooms with purple flowers and purple bracts, with a neat and uniform growth habit, making it an excellent cultivar.
2. True Lavender Series Lavandula
Native to the western and northern coasts of the Mediterranean, it is the most widely cultivated series in the world. Its characteristics are: the leaves are entire, the narrow leaves have slightly curled edges, densely covered with a layer of fine down, giving it a grayish white appearance. The flower spikes are cylindrical and slightly streamline-shaped, with small flowers arranged in a whorl on the flower axis. The calyx is cylindrical with fine serrations at the tip, and the small flowers extend from the calyx tube to bloom. The main species include:
2-1. Narrow-leaf Lavender (Lavandula angustifolia) The original species of narrow-leaf lavender originated in southern Europe, Italy, France, and Spain. It is called English lavender in Europe and the Americas and is distributed in the wild at altitudes above 1500 meters, known as mountain lavender. It has good cold resistance and grows well when planted in sunny, well-drained places, usually blooming from mid-June to July. The flower colors include blue-purple, light pink, and white. In the Pyrenees Mountains of Europe, a popular variety of English lavender, Pyrenean lavender (L.angustifolia subsp pyrenaica), was discovered. This variety has large bracts and blooms with deep blue-purple flowers, with a low growth habit and a stem height of about 35 cm. Narrow-leaf lavender is the most well-known and possibly the most widely cultivated type of lavender. The main varieties include Lady Lavender (L.Lady), Munstead Lavender (L.Munstead), Rose Lavender (L.Rosea), and Twickle Lavender (L.Twicke), etc. The cultivated varieties of narrow-leaf lavender are the most cold-resistant in the lavender family. The 1999-2000 edition of The RHS Plant Finder lists 40 cultivated varieties of narrow-leaf lavender, with 21 of them included in this Wisley trial. The essential oil produced from narrow-leaf lavender is the best among all lavender species and is used in the perfume industry to produce the highest quality perfumes. Most cultivated varieties of narrow-leaf lavender bloom with blue-purple flowers, especially eye-catching, and there are also some with pink or white flowers. Some of the better-performing cultivated varieties include:
2-1-1. Imperial Gem (L.angustifolia 'Imperial Gem') Flowers are deep blue-purple, with a plant height of 50-55 cm and a neat and uniform growth habit. It was selected from the popular old variety 'Hidcote' (L.angustifolia 'Hidcote'), which won the Royal Horticultural Society's Award of Garden Merit (AGM) in 1993.
2-1-2. Loddon Blue (L.angustifolia 'Loddon Blue') Flowers are blue-purple, with a compact plant shape and a height of 50 cm.
2-1-3. Beechwood Blue (L.angustifolia 'Beechwood Blue') Flowers are light blue-purple, with a rich color variation and a dense and compact growth habit, with a height of 45 cm.
2-1-4. Blue Cushion (L.angustifolia 'Blue Cushion') Similar to 'Beechwood Blue' in characteristics.
2-1-5. Twickle Purple (L.angustifolia 'Twickel Purple') The flower stems are slender, with deep blue-purple flowers and larger flowers, with a plant height of 30 cm. Its name commemorates a famous castle garden in Belgium. This is an excellent cultivar and won the Royal Horticultural Society's Award of Garden Merit (AGM) in 1993. Currently, multiple cultivars use this name, and it is difficult to identify and select the true 'Twickel Purple'.
2-1-6. Loddon Pink (L.angustifolia 'Lodden Pink') Bright pink flowers, with a plant height of 60-70 cm.
2-1-7. Miss Katherine (X-J) (L.angustifolia 'Miss Katherine') Deep red flowers with silver calyx.
2-1-8. Nana Alba (L.angustifolia 'Nana Alba') Neat and compact growth habit, with white flowers and silver or gray-green calyx.
2-2. Broad-leaf Lavender (L.latifolia) Also known as spike lavender and aromatic seasoning lavender, it is native to southern France and Spain. The leaves are wider and larger than those of narrow-leaf lavender, and the blooming period is later, with blooming in July in Beijing. When blooming, the flower stem can reach a length of 60 cm, with two to three nodes and a flower spike length of about 5 to 10 cm.
2-3. Cotton Wool Lavender (L.lanata) Native to southern Spain at an altitude of 180 meters, the plant size and shape resemble those of narrow-leaf lavender, but the leaves are shorter and densely covered with fine long hairs. Cotton wool lavender (L.lanata) did not appear in this Wisley cultivation trial. It is a distinctive and lovely species from the mountainous regions of southern Spain. Although it grows at high altitudes, it does not show reliable cold resistance in areas with humid winter climates, possibly due to the dense grayish white down on its leaves, which easily absorbs water droplets from humid air. If it is in autumn, the dry leaves of cotton wool lavender (L.lanata) are almost white in the sun, with delicate inflorescences, deep purple and smaller flowers, with many blooms. It won the Royal Horticultural Society's Award of Garden Merit (AGM) in 1993. Due to its poor cold resistance, cotton wool lavender (L.lanata) is difficult to cultivate.
3. Hybrid Lavender Series Hybrid
Based on the original species, some lavenders have been naturally hybridized or bred by researchers according to their advantages and disadvantages, and their growth habits, to create varieties that are more suitable for local planting. The total annual production of lavender essential oil worldwide is 1000 tons, with hybrid lavender accounting for 75%.
3-1. Dutch Lavender (L.intermedia) Also known as large lavender and hybrid lavender, it is a natural hybrid of narrow-leaf and broad-leaf lavender (Lavandula angustifolia x L.latifolia) and is widely cultivated. However, it does not originate from the Netherlands. Now, people often refer to them collectively as Dutch lavender (L.x intermedia Dutch Group). The book records 16 cultivated varieties, with 10 of them used in this Wisley cultivation trial. Most cultivated varieties of Dutch lavender (L. x intermedia) retain the wavy broad leaves of their parent broad-leaf lavender (L.latifolia), with silver-gray leaves, which are very distinctive. The plants are relatively cold-resistant and have the excellent characteristic of late blooming, usually blooming in mid to late July, with light blue-purple flowers that can bloom until September. The plant height is 80-130 cm, often forming a larger clump. Dutch lavender (L. x intermedia) currently dominates lavender commercial production cultivation because it has the highest essential oil yield per plant, although its essential oil quality is lower. Some of the better-performing cultivated varieties include:
3-1-1. Hidcote Giant (L.x intermedia 'Hidcote Giant') Plants have a neat and uniform growth habit, with a large number of flowers and dense inflorescences. 'Giant' does not refer to the size of the flowers, but to the solid and robust flower stems.
3-1-2. Forston (L. x intermedia 'Forston') Leaves are gray, with a neat and uniform growth habit and delicate inflorescences.
3-1-3. Large White (L.x intermedia 'Large White') Pure white flowers, with slender and long flower stems, one of the largest lavender cultivars, with a plant height of 130 cm.
3-1-4. Fragrant Memories (L.x intermedia 'Fragrant Memories') A very beautiful cultivar, with a growth height of 80 cm.
3-2. Sweet Lavender (L.heterophylla) A hybrid of narrow-leaf lavender and toothed lavender, it has a strong and fast-growing nature, with a plant height of up to 100 cm. The edges of the leaves at the base are slightly serrated, and as the leaves approach blooming, they tend to become smoother. Sweet lavender is a heat-tolerant variety that can be planted on a large scale, with a blooming period from April to May. It appears relatively thin, with blue-purple flowers and sweet-smelling leaves, making it the main variety for consumption.
3-3. Sawyer's Lavender (L.Sawyers) and Richard Gray Lavender (L.Richard Gray) They are cultivars selected by crossing cotton wool lavender (L.lanata) with narrow-leaf lavender (L.angustifolia). 'Richard' (Richard Gray) has leaves of an unusual gray color, densely covered with down, with a compact and neat plant shape, numerous inflorescences, blue-purple flowers, and a blooming period in July. The calyx is gray, making it a truly gray lavender that is also relatively cold-resistant. Its fragrance is as pleasant as that of its parents, and it was awarded the winner's prize in the trial.
4. Toothed Lavender Series (Dentata)
Native to France, this series is named after its leaves, which have deeply lobed serrated edges. The flowers of toothed lavender resemble those of French lavender, except that the small flowers in each whorl are less tightly packed, and there are no small flowers at the top, only bracts the same color as the flowers, which are not as prominent as those of French lavender. The flower color is purple-red. Toothed lavender has a plant height of about 50 cm, is not cold-resistant, is relatively heat-tolerant, and needs to be overwintered in protected facilities. The whole plant has a fragrant smell, suitable for viewing and environmental greening, and is also suitable for making tea. The main species include: toothed lavender (L.dentata) and gray toothed lavender (L.demara candieans) and their varieties.
5. Pinnate Lavender Series Pterostoechas
The native habitat is the southern coast of the Mediterranean in North Africa, with a particularly heat-tolerant nature. As the name implies, pinnate lavender has leaves deeply lobed into a feather shape, and each lateral lobe further divides into a second-order pinnate compound leaf, with the entire leaf outline being elliptical and the leaf surface having a layer of white powdery substance, giving it a slightly grayish white appearance. The plant height is about 50 cm, with a long flower stem and an inflorescence length of about 10 cm. The upper lip of the small flowers is larger, and the base of the inflorescence is easily regenerated to form a pair of branching inflorescences, forming a three-pronged shape. Another characteristic is that the whorled small flowers obviously open from bottom to top. Among the many pinnate lavender series, the most commonly introduced for cultivation are pinnate lavender (L.pinnata) and fern leaf lavender (L.multifida). These two types of lavender are very similar, with the main difference being that pinnate lavender plants are more erect, suitable for pot cultivation, with shorter down on the leaves and less obvious second-order pinnate leaves, while fern leaf lavender plants are more upward and oblique, suitable for courtyard beautification cultivation, with long down on the leaves and obvious second-order pinnate leaves.
The above shares the full content of the lavender variety introduction (chart), hoping to be helpful to plant enthusiasts!