Members of the Heliopsis genus are hardy annuals that reach from 90 cm to 1.5 m in height.
They carry large daisy / Sunflower like flowers of orange or yellow. Due to their large size they make great border flowers, where their weedy leaves can be hidden.
Some of the common names for Heliopsis include False Sunflower and Orange Sunflower.
Heliopsis helianthoides - False Sunflower by wackybadger.
False sunflower by daryl_mitchell.
Common Names: False Sunflower, Oxeye, Orange Sunflower, Gold root.
Life Cycle: Hardy perennial.
Height: 36 to 60 inches (90 to 150 cm).
Growing Region: Zones 3 to 9.
Flowers: Summer and early autumn.
Flower Details: Orange, yellow; discs often brownish. Daisy-like ray and disc florets. May be semi-double.
Foliage: Herbaceous. Green. Serrated. Opposite. Cordiform to deltoid.
Sow Outside: Cover seed. Start of spring or the beginning of autumn. Spacing 24 to 36 inches (60 to 90 cm).
Sow Inside: Germination time: one to two weeks. Temperature: 70°F (21°C). Start of spring - before the last frost or in early autumn.
Requirements and care: Full sunlight. Loam, moist. Soil pH 5.5 to 7.0. Can survive in dry soils. Some watering during dry periods. Provide a feed in the middle of the growing season. Cut back to the ground in autumn. Propagate: summer stem cuttings or by dividing in the spring.
Miscellaneous: Attractive to butterflies. Name comes from the greek for sun (helios) and appears (opsis).
When growing False sunflowers it is best to sow the seed outside in either early spring or at the beginning of autumn. Simply cover the seed with a light dusting of topsoil. They like to grow in a sunny part of the garden that has a rich loamy soil with slightly acidic to neutral pH (5.5 to 7).
If you would like to first grow False Sunflowers (Heliopsis) indoors as seedlings then this should be started about 9 or 10 weeks before the seedlings are due to be transplanted into the garden either at the beginning of august or before the last frost of spring. They should be spaced at about 60 to 90 cm apart.
If you require more false sunflowers and other Heliopsis Plants in the garden, then they can be divided in the spring or cuttings took from the stems in the summer.
Heliopsis plants can grow in dry soil but it is best to water them occasionally and to apply a light fertilizer in the middle of the growing season. Once flowering has finished cut back the plats to the ground in the autumn.
I hope that you enjoyed this guide on how to grow Heliopsis plants. Updated September 2020.