Strawflowers were previously classified as a member of the genus Bracteantha but now are in the Xerochrysum genus. This fast-growing Australian native is a part of the Asteraceae family, a group that includes many daisy-type flowers. Plant strawflower after the last frost date in your region. Regular deadheading the plant will keep the flowers blossoming during the growing season.
Light
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.
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.
Water
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.
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.
Fertilizer
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.
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.
How to Grow Strawflower 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.
Common Pests & Plant 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.
