The common name of the herbaceous perennial evergreen Lavandula angustifolia shrub is English Lavender.
Its name depicts England because it thrives in the English climate; it is actually a native of the mountains of western Mediterranean regions. It is also referred to as narrow-leaved, true and common lavender.
It is a member of the ~7000 strong mint/dead nettle family (Lamiaceae) and is therefore closely related to species belonging to the Mentha, Nepata, Satureja, and Salvia genera. The Lavandula consists of 39 species, and in addition to Lavandula angustifolia, other frequently grown plants include* L. latifolia (Spike/Portuguese), L. lanata (Woolly/Silver leaved), L. multifida (Egyptian), L. pedunculata (French), L. stoechas (French/Spanish), L. dentata (French), and L. pinnata (Fernleaf).
Lavandula angustifolia photograph by Maja Dumat.
Plants are easy to grow, have an attractive fragrance, and can be used for culinary purposes. They attract bees and look great in borders, when used as a small hedge, or as container plants.
English Lavender is a great plant to grow to attract bees to your garden. Picture by Tim Ford.
As Lavandula angustifolia is drought tolerant they make an ideal plant to grow in drier regions and areas that have hosepipe restrictions in the summer. They are also fairly tolerant to deer and rabbits. English lavender is grown commercially for its perfume oils, and often used in aromatherapy, making herbal teas, and in potpourris sachets.
*Common names in brackets; note overlap of common names.
Plants are semi-woody and reach a height of 18 to 36 inches (45–90 cm) with a similar spread (18 to 60 inches/45–150 cm). They have narrow evergreen grey-green leaves that are about 1 to 2.5 inches (2.5 to 6 cm) long. The hermaphrodite flowers bloom from late in spring through the months of summer. Lavandula angustifolia flowers gives rise to the color of the same name, and appear on terminal spikes. Like the leaves, the flowers are very aromatic.
A commonly grown variety is Lavandula angustifolia Hidcote; this is named after Hidcote Manor in Gloucestershire. It is smaller than true lavender reaching a height of about 20 inches (50 cm), with 1.5 inch (4 cm) flower spikes.
Seeds can be sown (lightly-cover) in the spring under a cold-frame and will take from two to ten weeks to germinate. Note that seeds from Lavandula angustifolia Hidcote will not stay true (Cultivate by talking cuttings in the summer).
If growing as part of an hedge space lavender at 12 inches (30 cm apart) or slightly further for larger varieties (18 inches/45 cm). If growing in borders space at about 36 inches (90 cm).
Container grown lavender plants will perform best in a pot of 16 inches (40 cm) that contains multipurpose compost that is enhanced with coarse grit to improve drainage. Use a slow release fertilizer.
Plants should be located in a sunny area that has a well-drained average to medium-fertile soil, and ideally a sandy and slightly alkaline (ph 7.5) nature. Plants should grow well in zones 5–9.
Lavender plants are drought-tolerant so only water sparingly. If grown in bad drainage or over-watered plants will become woody and be short-lived.
If collecting flowers for dry displays cut them off before flowering occurs, otherwise cut back flowers to about 1 inch (2.5 cm) of previous growth following blooming.
Dead-head plants in the autumn to maintain vigour. Prune plants to maintain shape when new leaves emerge in the spring, and cut back plants to about 8 inches (20 cm) every three years (spring). You can also prune plants in late summer once flowering has finished if you prefer.
Lavandula angustifolia is susceptible to root rot so do not over-water or grow in areas of poor drainage. If growing in humid areas use a rock mulch to prevent dampness. Other common problems include grey mould, leaf spot, Rosemary leaf beetle, Sage leafhopper, and froghoppers.