Delphinium Pacific Giants

Published February 24, 2016

By now you, and 9,692 avid gardeners, have seen the National Garden Bureau’s announcement that 2016 is the year of the Delphinium. Benary’s Pacific Giants come in a full color range, with cut-flower quality blooms, but they don’t need vernalization, so they can be grown right along with your annuals. Here are some tips on growing Delphinium Pacific Giants.

For more information:www.benary.com

Production

Garden height: First year 35 to 47” (120 cm); second year 59” (150 cm)
Cut flower vase life is about 10 to 12 days
Crop time: 16 weeks; flowering pots 18 to 22 weeks (from sowing); cut flower production 18 to 22 weeks (from sowing)
Sowing method: 2 to 3 seeds per plug
Germination: 12 to 18 days at 70 to 75° F (21 to 24° C). Cover seeds with vermiculite, sand or substrate.
Sowing media: Use a well-drained growing substrate with low soluble salt levels and pH between 5.5 to 6.5. Begin with a saturated (5) media to start but dry back to a Wet (4) on day 4 and continue at a wet until they germinate completely. Keeping them too wet will result in losses. Feed early at rates of 60 ppm N using a calcium-based feed.

Growing On:

Temperature: Grow indoors at 59 to 64°F (15 to 18°C). In spring, forcing will take about 10 to 12 weeks at 59 to 64°F (15-18°C). Vernalization is not required for flower initiation. Warmer temperatures of 60 to 64°F will speed up the crop significantly. In the early stages, grow cooler until they begin to send up flowers.
Fertilization: Use low rates of fertilizer in the early stages and increase the levels after transplanting. Moderate to high levels of feeding using a calcium-based fertilizer. 15-5-15 or 14-4-14. Fertilize the crop weekly with 100 to 150 ppm nitrogen (slow release fertilizer in substrate), using a complete balanced fertilizer. Avoid high ammonium and high nitrogen levels. In spring, fertilize with 100 to 150 ppm nitrogen using a complete balanced fertilizer. Prevent magnesium deficiency by applying magnesium sulphate (0.05%) one to two times. In case of iron deficiency apply iron-chelate one to two times. Fertilization with slow release fertilizer is preferred to fertilization with complete balanced fertilizer, because the roots are very sensitive to high salt levels in substrates. Discontinue feeding during flowering stages.

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