Id-Code: RA 183
Family: Asteraceae, Compositae
Origin: North America: Ohio und Michigan south to Georgia, west to Oklahoma and northeast Texas
Special Features: More intense, carmine-red colored blossoms compared to the award-winning 'Magnus'
History: Introduced by JELITTO PERENNIAL SEEDS in 2000
Distinction: Award of Garden Merit (A.G.M.) from The Royal Horticultural Society
Colour: Carmine-red
Natural Flowering Period: July - September
Winter Hardiness Zones: Z3-8
Growth Habit: Clumping/Upright
Foliage: Ovate-lanceolate; 20 x 10 cm (8'' x 3'')
Height with Flower: 100 cm (40'')
Spacing between Plants: 45 cm (18'')
Soil Requirement: Well-drained soils, pH 5.8 - 6.8
Location: Full sun
Use: Plant 'Rubinstern' together in the border with Angelica pachycarpa, Knautia macedonica and Verbascum 'Violetta'
Specialities: Great as a cut flower, either in bloom, or in the early stages of seed development. The original true seed of 'Rubinstern' and 'Magnus' is available only from Jelitto.

Cultural Tips:
Grams per 1000 seeds: 4
Seeds per Gram: 250
Seeding Recommendation: 10g / 1000 plants
Sowing Rate: 2-3 seeds per cell
Plug tray recommended size(s): 72 or 128
Germination: Rapidly germinating, keep seed in constant moisture (not wet) with temperatures of about + 20°C (68°F). The seed must be covered thinly. Keep in cooler conditions after germination occurs. The germination might be slower and more irregular. This poses no problems.

Scheduling:
Best Sowing Dates: Anytime
Sowing to Germination: 2 - 3 weeks
Germination to Transplant: 4 - 8 weeks
Transplanting to Salable Plant: 6 - 10 weeks
Cutting-Back at Transplanting: Not Necessary

Growing On:
Container Size(s): 1-2 plugs per 11/12 cm (4 1/2''); 2-3 plugs per 15 cm (6'')
Vernalization: Some flowering will occur the first year without vernalization, but improved flowering will occur the 2nd year; and 3-10 weeks of cool temperatures might benefit fuller flowering in the first year.
Forcing: There has been no research on 'Rubinstern', but an obvious place to experiment - following vernalization - would be raising daytime temperatures to 60° - 65°F (15° - 17°C). Provide 16 hours of continuous lighting. During the short days of winter, provide a night interruption lighting of 4 hours between 10:00 p.m. and 2:00 a.m. Some later flowering species can be forced in 14 - 16 weeks and perhaps sooner at warmer temperatures. Further experiments are warranted with 'Rubinstern'.
Fertilization: Medium (150-200 ppm)