Rubinstern (Ruby Star)

Family: Asteraceae Herb

Planting Schedule

Provide your location or planting zone to unlock dates and add Rubinstern (Ruby Star) to a garden.

Rubinstern (Ruby Star) blooms with a radiant, ruby-red brilliance that seems to glow above sturdy, upright stems—petals that flare like a starburst and a bold, dark center that holds the gaze.

The flowers carry a firm, slightly velvety texture and a long-lasting presence in the garden, making them as satisfying in the landscape as they are in fresh bouquets. Grow Rubinstern for dependable summer color and a pollinator magnet that keeps visiting wings returning from bud to bloom.

Light: Full SunMaturity: 70 DaysHabit: Upright

Botanical illustration of Rubinstern (Ruby Star)

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Rubinstern (Ruby Star) Planting Dates by USDA Zone

Estimated US hardiness-zone windows for sow, transplant, and harvest. Enter a US ZIP above for exact local dates, or open a zone below.

Zone	Start Indoors	Sow / Transplant	Harvest
Zone 1a	Apr 20th	Jul 27th	Oct 5th – Jul 15th
Zone 1b	Apr 6th	Jul 13th	Sep 21st – Aug 1st
Zone 2a	Mar 30th	Jul 6th	Sep 14th – Aug 29th
Zone 2b	Mar 20th	Jun 26th	Sep 4th – Aug 25th
Zone 3a	Mar 20th	Jun 26th	Sep 4th – Sep 1st
Zone 3b	Mar 24th	Jun 30th	Sep 8th – Sep 21st
Zone 4a	Mar 20th	Jun 26th	Sep 4th – Sep 24th
Zone 4b	Mar 18th	Jun 24th	Sep 2nd – Sep 27th
Zone 5a	Mar 13th	Jun 19th	Aug 28th – Sep 30th
Zone 5b	Mar 9th	Jun 15th	Aug 24th – Oct 5th
Zone 6a	Mar 6th	Jun 12th	Aug 21st – Oct 10th
Zone 6b	Feb 28th	Jun 6th	Aug 15th – Oct 16th
Zone 7a	Feb 23rd	Jun 1st	Aug 10th – Oct 20th
Zone 7b	Feb 13th	May 22nd	Jul 31st – Oct 28th
Zone 8a	Feb 4th	May 13th	Jul 22nd – Nov 5th
Zone 8b	Jan 26th	May 4th	Jul 13th – Nov 12th
Zone 9a	Jan 9th	Apr 17th	Jun 26th – Nov 26th
Zone 9b	Dec 15th	Mar 23rd	Jun 1st – Dec 9th
Zone 10a	—	Oct 1st	Dec 10th – Feb 28th
Zone 10b	—	Oct 1st	Dec 10th – Feb 28th
Zone 11a	—	Oct 1st	Dec 10th – Feb 28th
Zone 11b	—	Oct 1st	Dec 10th – Feb 28th
Zone 12a	—	Oct 1st	Dec 10th – Feb 28th
Zone 12b	—	Oct 1st	Dec 10th – Feb 28th
Zone 13a	—	Oct 1st	Dec 10th – Feb 28th
Zone 13b	—	Oct 1st	Dec 10th – Feb 28th

Crop Details

Trait	Value
Days to Maturity	70
Sun Requirements	Full Sun
Growth Habit	Upright
Support Needed	None
Planting Depth	Normal
Germination Temp (°F)	70
Min Soil Temp (°F)	60
Min Night Temp (°F)	50
Harden Off (days)	7

Frequently Asked Questions

What’s a common pest or disease on Echinacea purpurea (purple coneflower) and how can I fix it?

Echinacea purpurea is commonly affected by powdery mildew, especially in humid weather and when plants are crowded. Improve airflow by spacing plants and watering at the soil line (not the leaves), then spray with a labeled fungicide at the first signs of white powdery growth. Remove heavily infected leaves early to slow spread.

How often should I water Echinacea purpurea during its main growing phase?

During active growth (after plants establish and before flowering), keep soil evenly moist but not soggy—aim for watering about 1 inch per week total, split into 1–2 deep waterings if needed. Let the top 1–2 inches of soil dry between waterings to prevent root stress and reduce mildew risk. Once established, it will tolerate some dryness, but consistent moisture helps it form strong stems and flowers.

How do I know when to harvest or cut back Echinacea purpurea (Ruby Star) at the right time?

For cut flowers, harvest when the ray petals (the pink-purple “daisy” petals) are fully open and the central cone is firm and visibly developed, typically around 70 days from sowing. For seed, leave the flower heads until the cones turn dark and crisp and seeds start to loosen—then cut heads and finish drying indoors. Deadhead spent blooms to encourage additional flowering, cutting back to just above a healthy leaf set.