Members of the Helichrysum genus are half hardy annuals or hardy perennial plants that flower from summer through to the first frost of winter.
They carry long lasting paper like flowers of orange, yellow, red, or white; the flowers may be two-coloured.
Helichrysum vestitum by Peter Baker; creative commons.
They reach about 30 cm to 1.2 m (one to four feet) in height.
Some of the common names for Helichrysum include Curry plant, Immortelle, Licorice plant and Strawflower.
When growing curry plants and other Helichrysum members sow the seed on the surface after the last frost of spring.
It may be best to start growing curry plants (Helichrysum) indoors first to get a head start.
The growing process should start about eight weeks before putting the plant outdoors, a few weeks after the last frost of spring.
Germination will take from one to three weeks and should be performed in the light at a temperature of about 18 to 23 degrees Centigrade (65°F to 73°F).
Once the seedlings are ready for transplanting, they should be spaced at about 20 cm (8 inches) apart (small varieties) to 40 cm (16 inches) apart (larger species).
Helichrysum prefer to grow in sunny areas with a sandy soil of pH 6 to 7, though they will tolerate poor soil too.
Once growing, if you require more Helichrysum plants, then cuttings can be took in the summer. Or you can simply let the Curry plant set seed, and allow it to grow by itself.
An interesting trick with the Helichrysum plant is to remove all of the flowers but one, on each inflorescent stem; this will result in single big flowers atop of each stem.
Helichrysum petiolare is a native of southern Africa and is commonly referred to as the (Licorice) Liquorice plant.
It has a distinct liquorice smell, hence it's common name.
They reach about 45 to 60 cm (16 to 24 inches)in height, with a spread of about 90 to 120 cm (1.2 m).
Plants are perennial sub-shrubs, with a trailing nature. Stems are woody, while the gray-green leaves help to give the plant a silvery appearance. These leaves are ovoid to circular in shape, and have a soft, somewhat wooly, texture. Its dense foliage and trailing nature make for attractive and aromatic groundcover plant.
Wild-type plants have tiny white flowers, but cultivars with pink, yellow, or orange flowers are also available.
Leaves of Helichrysum Petiolare Variegata cultivar, photograph by Serres Fortier; CC.
It grows well is US zones 9 to 11, so is hardy to about −1°C (30°F). This puts it into between RHS zone H2 to H3, but it should more likely classed as a tender as opposed to a half-hardy plant because it will struggle if freezing occurs over concurrent days.
one of the most important things for successful growth is excellent drainage. They enjoys full sunlight and can also be grown in partial shade. Average and poor soils should be fine, with drier soils ideal.
Liquorice plant growing en-masse as coverage, photograph by Forest and Kim Starr; CC.
If you are planning to grow Helichrysum Petiolare plants in cooler areas, then plant into containers and bring indoors at the first hint of any frost.
These plants are not usually grown for their flowers, so you may wish to remove them as they appear.
Helichrysum gymnocephalum is seldom grown as a garden plant but more oft used in the creation of essential oils.
Dried Helichrysum gymnocephalum, photograph by R. Decary (Public domain).
Helichrysum italicum is an evergreen aromatic sub-shrub. It reaches from 30 to 60 cm (1 to 2 feet) in height.
Plants carry yellow flowers, which typically flower in May and June in its native Italy.
Helichrysum italicum flower, photograph by It's No Game; CC.
It gets its common name 'the Curry plant' because it has a similar smell to curry, and indeed this plant may be used as a spice. Though it smell is more reminiscent of plants belonging to the Artemisia plant and Salvia plant genera.
Ideally, grow Helichrysum italicum in a part of the garden that has full sunlight. It prefers aa poor to moderate sandy (or rocky) dry soil, that has good drainage. Plants are drought tolerant. The soil pH can be neutral or alkaline. As it is frost tender it does well to UK RHS zone H3 (-5°C, 23°F), and USDA zones 8 to 11 in North America.
This plant is linked to numerous medicinal properties: See this article listed on Research gate for both its traditional and modern usages.
Shaped Curry Plant bush, photograph by cultivar413; CC.
Helichrysum arenarium is a dwarf member of the genus. It is a perennial that reaches about 30 cm (one foot) in height.
Plants carry two types of leaves, elliptical at the bottom of the plant, and linear towards the top. Flowers are yellow and are a rich source of phenolic compounds. See Frontiers in Plant Science for its botanical uses.
It readily grows in USDA hardiness zones 4 to 8, making it hardy to about -35°C (-30°F). It is considered hardy in the UK at RHS zone 4.Helichrysum arenarium grows well in sandy soils and loam that has good drainage.
Helichrysum arenarium, the Dwarf everlast, image by Rob bakker; CC.