Cotton Lavender (Santolina chamaecyparissus)

Cotton Lavender, Lavender Cotton, Santolina

Cotton lavender is a plant species native to the western and central Mediterranean region. The leaves and stems of cotton lavender can be used in the production of perfume and insect repellent. The scientific name, Santolina chamaecyparissus, means “like ground cypress,” due to the plant’s appearance, but the species is not genetically related to cypress.

I. Appearance and Characteristics 

Santolina chamaecyparissus (syn. S. incana), known as cotton lavender or lavender-cotton, is a species of flowering plant in the family Asteraceae, native to the western and central Mediterranean.

It is a small evergreen shrub growing to 50 cm (20 in) tall and broad. Densely covered in aromatic, grey-green leaves, in summer it produces masses of yellow, button-like composite flowerheads, held on slender stems above the foliage. The disc florets are tubular and there are no ray florets.

This plant is valued in cultivation as groundcover or as an edging plant for a hot, sunny, well-drained spot, though it may be short-lived. Once established, plants can tolerate dry and poor soils. Its compact shape can be maintained by cutting back in spring.

Numerous cultivars have been produced, of which ‘Nana’, a dwarf form growing to 25 cm (10 in), has gained the Royal Horticultural Society’s Award of Garden Merit.

II. How to Grow and Care

Sunlight

Lavender cotton grows best in full sun, which encourages the best color foliage and most compact habit. Give lavender cotton as much sun as possible, as it flourishes in hot and dry summer weather. Although it can tolerate part shade, the plants require more maintenance because part shade encourages floppiness and a more open, sprawling habit.

Temperature and Humidity

Lavender cotton plants thrive in warm, dry areas with temperatures in the 65°F-80°F range. They tolerate summer temperatures up to 95°F and cold temperatures to 15°F for short periods.

Soil and Water

In addition to being well-draining, soil for lavender cotton should be nutrient-poor; rich soil makes plants floppy and weak-wooded. Like many other Mediterranean plants, lavender cotton prefers alkaline soil over acidic soil.

This drought-tolerant plant prefers dry to medium-dry soil. During their first year, give young plants an inch of water a week. After that, water established plants twice a month if there is little rain.

Fertilizing

Lavender cotton doesn’t need fertilizer. If nutrition in the soil needs some refreshment, a light dressing of compost in early spring is enough. Do not feed Santolina chamaecyparissus as it is used to living in nutrient-deficient, sandy soil.

Planting Instructions

When planting lavender cotton, consider its native Mediterranean climate. It enjoys full sun and well-drained and gritty soil and doesn’t tolerate excessive moisture.

Lavender cotton is readily available as nursery-grown plants. Choose a well-draining planting area, but don’t add compost to improve the drainage. Compost makes soil more acidic, while lavender cotton prefers slightly alkaline soil. Dig a hole twice as wide and the same height as the nursery container. Settle the new plant in the soil at the same depth it was in the nursery container. Backfill the hole, pressing down with your hands to prevent air bubbles. When planting multiple plants, space them 3 feet apart.

In cool areas, plant lavender cotton plants in spring so they have time to become established before winter. In temperate areas, plant lavender cotton in spring or fall.

Lavender cotton seeds can be started inside before the last spring frost for later transplanting into the garden.

Pruning

One of the many reasons gardeners grow lavender cotton is its tolerance for repeated shearing, which makes it an excellent option for topiaries and hedges. Even when not growing in a formal garden, this plant benefits from occasional trims to keep looking neat and healthy.

Propagation

Lavender cotton is easy to start from cuttings, seeds, or by layering.

  • Layering

Pull down a low branch and shallowly bury a section of it in the soil with both ends exposed, weighing it down with a rock if needed to hold it in place. After a few weeks, roots will develop. At this time, sever the branch to remove the rooted part from the main plant and plant the rooted cutting in a new area.

  • Seed

Prepare a seed flat by filling it with moist vermiculite eight weeks before the last spring frost. Press the seeds into the planting medium, lightly dusting them with fine vermiculite, but don’t cover them. They require light to germinate. Place the seed flat in an area where it receives a steady 68°F and water it sparingly. Germination occurs one to three weeks later. Transplant to the garden after the last spring frost.

  • Cuttings

Take stem cuttings no longer than 3 inches from fresh growth during warm months. Stems that are brown are too old to root successfully. Remove the foliage from the bottom two-thirds of the cutting, leaving the tip intact. Fill a seed flat or small container with moistened perlite or a mix of perlite and compost. Make a small hole in the perlite for each cutting. Dip the cuttings in rooting hormone, insert them into the planting medium and firm it around them. Water the container sparingly and put it in a sheltered area away from the sun and wind. After that, water it only when the planting medium is dry to the touch. Too much water causes the cuttings to rot. It takes two to three months for the cuttings to root.

Potting and Repotting 

Small lavender cotton plants or seedlings can grow in containers with good drainage as houseplants. Choose a container larger than the plant’s root ball and fill it with a potting mix. Carefully loosen the plant’s roots with your hands before planting it. Keep the container and plant in a warm, well-lit spot, such as a south or east-facing window. Water it once a week. As the plant grows, transplant it to a larger container as needed.

Pests and Diseases

  • Common Problems

Over-watering can be a major problem for lavender cotton. Excess moisture can cause the roots to develop destructive diseases. If you’re growing them in your garden, watering is required twice a month. Similarly, don’t fertilize your plant with more than a light layer of compost once per year.

  • Common Pests

Lavender ground cover is virtually pest-free. The oils in its aromatic foliage not only keep away rabbits and deer, but insects also don’t appreciate it either.

  • Common Diseases

Poorly drained soils can lead to basal crown rot and fungal root rot, which can be prevented by reducing watering. If you don’t have success with withholding water, you can try to replant the shrub in fresh, dry potting media. If that doesn’t change the situation, remove the entire plant and dispose of it in the trash.

III. Types of Lavender Cotton

  • Gray Santolina

Santolina chaemacyparissus, gray santolina, also known as lavender cotton, is named for its soft, silvery-gray foliage that forms a mound up to 2 feet tall and 3 feet wide. The plant can be sheared to keep it more compact. It bears buttonlike yellow blooms in early summer. These can be sheared back after bloom to keep the plant tidy. Zones 6-9.

  • Green Santolina

Santolina rosmarinifolia is called green lavender cotton and formerly was classified as Santolina virens. The plant has fine-texture, fragrant, medium-green foliage and grows 1-2 feet tall. In spring, it bears buttonlike yellow flowers. It is a good choice for rock gardens and herbal knot gardens. Avoid overwatering it to prevent the stems from flopping open in midsummer. Zones 7-9

  • Dwarf Lavender Cotton

Santolina chaemacyparissus ‘Nana’ is a dwarf form of lavender cotton. It grows to only 1 foot tall and 2 feet wide. The silver-gray foliage is fragrant and covered with bright, golden-yellow globe-shaped flowers in summer. ‘Nana’ is longer-lived than other lavender cotton cultivars. Zone 6-9

IV. Uses and Benefits 

Cotton lavender is a beautiful evergreen perennial (sometimes annual) considered essential in Mediterranean gardens. Its dense and silvery foliage makes a wonderful groundcover, border plant, or accent piece for shower flowers. Cotton lavender is very suitable for rock gardens, pathways, or anywhere with a little too much green. It pairs great with Mediterranean herbs, such as lavender, thyme, and rosemary.

Cotton Lavender (Santolina chamaecyparissus) Details

Common name Cotton Lavender, Lavender Cotton, Santolina
Botanical name Santolina chamaecyparissus
Plant type Ground Cover
Hardiness zone 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b
Growth rate Medium
Harvest time Fall
Height 1 ft. 0 in. - 2 ft. 0 in.
Width 1 ft. 0 in. - 2 ft. 0 in.
Sunlight Full sun (6 or more hours of direct sunlight a day)
Soil condition Sand
Flower color Gold/Yellow
Leaf color Gray/Silver