General Culture:

Best grown in light, medium moisture, organically rich, well-drained loams in full sun to part shade. Avoid wet or poorly-drained soils. ‘Astra Semi-Double Blue’ is easily grown from seed. Division and transplanting are possible but tricky because of the fragile, fleshy root systems of these plants, and it is probably best to leave plants undisturbed once established. Deadheading spend flowers generally prolongs the bloom period. New season plant stems emerge late in spring, so gardeners must be careful not to damage crowns by early cultivation (leaving old plant stems in place throughout winter to the point when the new growth first appears helps mark plant locations). Staking is usually not necessary because of the short stems of this compact cultivar.

Noteworthy Characteristics:

Balloon flower is a clump-forming perennial that is so named because its flower buds puff up like balloons before bursting open into outward-to-upward-facing, bell-shaped flowers with five pointed lobes. The Astra series of balloon flower (see ‘Astra Pink at C476 and ‘Astra Blue’ at Z620 herein) consists of a variety of different seed-grown forms including single, semi-double and double flowers in white, lavender, blue and pink. Astra series plants reportedly are more vigorous plants with better seed germination rates and better flowering. ‘Astra Semi-Double Blue’ is a dwarf/compact cultivar that produces fluffy, semi-double, blue flowers (to 3” across) singly or in small clusters atop stems typically growing to only 6-12” tall with a spread to 8” wide. Flowers bloom throughout the summer. Ovate to lance-shaped, toothed, blue-green leaves. Platycodon in Greek means broad bell in reference to the flower shape.

Problems:

No serious insect or disease problems. Root rot may occur in overly moist soils. Warch for slugs and snails. Plants emerge late in spring.

Uses:

Rock gardens or border fronts. Containers. Edging.

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