The strawflower (Xerochrysum bracteatum) bears a superficial resemblance to daisies. However, the petals aren’t really petals, but “bracts,” or specialized leaves usually situated at the base of a flower. In this plant, they have a feeling of starched paper. These showy flowers are prized for their vivid yellow, orange, red or pink coloring.
I. Appearance and Characteristics
Xerochrysum bracteatum, commonly known as the golden everlasting or strawflower, is a flowering plant in the family Asteraceae native to Australia. Described by Étienne Pierre Ventenat in 1803, it was known as Helichrysum bracteatum for many years before being transferred to a new genus Xerochrysum in 1990.
The plant is an erect perennial, or occasionally annual, herb that is simple or rarely branched at its base. It generally reaches 20 to 80 cm (8 to 31.5 in) in height, but can have a prostrate habit in exposed areas such as coastal cliffs. The green stems are rough and covered with fine hairs, and are robust compared with those of other members of the genus. The leaves are lanceolate, elliptic, or oblanceolate in shape and measure 1.5 to 10 cm (0.59 to 3.94 in) long and from 0.5 to 2 cm (0.20 to 0.79 in) wide. They are also covered with cobwebby hairs. Sitting atop tall stems above the foliage, the flower heads range from 3 to 7 cm (1 to 3 in) in diameter. Occasionally, multiple heads arise from the one stem. Like the flowers of all Asteraceae, they are composed of a central disc which contains a number of tiny individual flowers, known as florets; these sit directly on an enlarged part of the stem known as the receptacle.
Around the disc is an involucre of modified leaves, the bracts, which in Xerochrysum, as in most Gnaphalieae, are petal-like, stiff, and papery. Arranged in rows, these bracts curl over and enclose the florets, shielding them before flowering. They create the impression of a shiny and yellow corolla around the disc. The intermediate bracts are sometimes white, while the outer ones are paler and often streaked reddish or brown (a greater variety of colours are found in cultivars). These bracts are papery and dry, or ‘scarious’, with a low water content, unlike leaves or flower parts of other plants. They are made up of dead cells, which are unusual in that they have a thin primary and a thick secondary cell wall, a feature only found in sclerenchyma, or structural cells, not cells of flowers or leaves.
The individual florets are yellow. Those on the outer regions of the disc are female, while those in the centre are bisexual. Female flowers lack stamens and have only a very short, tube-shaped corolla surrounding a pistil that splits to form two stigmas, while bisexual or hermaphrodite flowers have a longer corolla, and (as in virtually all members of the family) five stamens fused at the anthers, with the pistil emerging from the center. The yellow corolla and pistil are located above an ovary with a single ovule, and surrounded by the pappus, the highly modified calyx of Asteraceae. It comprises a number of bristles radiating around the florets. Yellow in colour, they persist and are thought to aid in the wind dispersal of the 0.3 cm (0.12 in) long fruit. The smooth brown fruit, known as a cypsela, is 2 to 3 mm long with the pappus radiating from one end.
In the wild, X. bracteatum can be distinguished from X. bicolor in Tasmania by its broader leaves and cobwebby hairs on the stems, and from X. macranthum in Western Australia by the flower head colour; the latter species has white flower heads whereas those of X. bracteatum are golden yellow. Xerochrysum subundulatum from alpine and subalpine areas of New South Wales, Victoria, and Tasmania is rhizomatous, and has markedly pointed orange bracts. The eastern Australian species X. viscosum may be distinguished by its rough and sticky leaves.
Xerochrysum bracteatum occurs in all Australian mainland states and territories, as well as Tasmania. Widespread, it is found from North Queensland across to Western Australia, and in all habitats excluding densely shaded areas. It grows annually in patches of red sand in Central Australia, responding rapidly to bouts of rainfall to complete its life cycle.
It is common among granite outcrops in southwest Western Australia, and is found on heavier and more fertile soils in the Sydney region, such as basalt-, shale-, or limestone-based soils, generally in areas with a high water table. Associated species in the Sydney Basin include blackbutt (Eucalyptus pilularis) in open forest, and the shrubs Empodisma minus and Baloskion australe in swampy areas. It has been reported growing in disturbed soil, along roadsides and in fields in the New England region in the United States.
II. Strawflower Varieties
- ‘Bright Bikini’: Topping out at 1 foot tall, this is a good choice for containers or the front of the border.
- ‘Monstrosum’: Fully double flowers in orange, pink, red, and white are a crafter’s favorite.
- ‘Sundaze’: A Proven Winners introduction in yellow and orange hues, it won awards in Cornell University and Penn State plant trials.
- ‘Tom Thumb’: In contrast to the standard height of 40 inches, this mix won’t surpass about 15 inches, making it an ideal companion for a sunny container garden or window box.
III. How to Grow and Care
Sunlight
Strawflowers thrive in full sun, although they can tolerate part shade. In the latter case, they won’t bloom quite as much. Growing strawflowers in full sun will help prevent weak stems that flop.
Temperature and Humidity
Strawflowers do best in temperatures of 65 to 70 degrees Fahrenheit during the day and 60 degrees at night. Strawflowers are not frost-tolerant, so they grow best in warm weather and prefer low humidity.
Watering
These drought-tolerant flowers will still be blooming brightly in the garden after a week of dry weather, but don’t let them wither in an extended period of drought. Weekly watering will keep the flowers perky and fresh. In the absence of rain, give them about 1 inch of water a week during the growing season but don’t let the roots of the plant get overly soggy.
Soil
Sandy and rocky soils with a mildly acidic to neutral pH (5.5 to 6.5) are preferred over rich and heavy soils, but any soil is fine as long as excellent drainage is present. Add mulch to retain soil moisture and even the soil temperatures. When planting in the garden, dig up the soil to a depth of 10 to 12 inches and blend in 3 inches of compost.
Fertilizing
Although not heavy feeders, a monthly application of balanced flower fertilizer will keep your strawflowers blooming steadily. Strawflowers grown in containers need more frequent fertilizing than those planted in the garden, about every two weeks. For amounts, follow the instructions on the label.
How to Grow From Seed
Strawflowers are best grown from seed. To start them indoors, time your indoor seed-starting about six to eight weeks prior to the average last frost date in your area. Press seeds lightly into moist soil, but don’t cover them, as light hastens germination. Seedlings should begin to appear in seven to 10 days.
Give the seedlings plenty of light from a window or grow them beneath fluorescent plant lights that are on for 16 hours of the day. Harden-off your transplants for two weeks or so, then transplant them into the garden after night temperatures reach about 60 degrees Fahrenheit.
Pests and Diseases
Strawflowers are generally pest and disease-free, but aster yellows virus can affect the plants. This disease is most problematic in areas with leafhopper infestations, where the insect acts as a vector. Affected plants will exhibit yellowing of leaves and stunted growth. Once a plant has been infected, it cannot be treated but it is important to remove infected plants promptly to prevent the disease from spreading.
III. Uses and Benefits
As the common name “strawflower” suggests, this plant is valued for its large, papery flower heads that are everlasting and retain all their color upon drying. They are commonly cultivated for used in dried flower arrangements. In horticulture, strawflower is ideal for cottage, informal, rock, and Mediterranean gardens as a colorful addition to flower borders and beds.
