Germination temperature
Cool to mild; in the wild seedlings emerge mainly in spring and autumn.
Herb growing guide
Bladder campion is a hardy, deep-rooted perennial with white flowers above inflated, veined calyces, and tender young shoots that are picked as a spring green. It grows easily from a shallow sowing in cool to mild weather, in spring or autumn.
Cool to mild; in the wild seedlings emerge mainly in spring and autumn.
Shallow; the kidney-shaped seed is up to 1.5 mm long.
No reliable day count is published; emergence can be spread out.
Full sun or partial shade for the plant.
Not needed for a spring or autumn sowing.
Sow in containers in a cold frame and transplant, or sow direct.
The seed is small, dark grey and kidney-shaped, up to 1.5 mm long. Sow it thinly as supplied.
Not needed. The seed has no hard coat that must be broken.
Not needed as a separate step. Autumn sowing in a cold frame, as the RHS advises, lets winter cold act naturally on the seed.
Not needed.
No reliable optimum is published for this species. In the wild, seed germinates at almost any time of year, with peaks in spring and autumn, so mild rather than hot conditions suit it. In India, sow in the cool season after the monsoon.
Sow shallowly and cover lightly; seedlings emerge from shallow depths.
A free-draining seed mix. Adult plants prefer moderately fertile, well-drained loam or chalky soil that is neutral to alkaline.
Keep the mix just moist. Avoid waterlogging, as the plant is adapted to well-drained ground.
No special light treatment is needed for the seed; give seedlings good light to keep them compact.
Not documented in reliable sources. Leave containers in place, as some seedlings may appear later than others.
Transplant seedlings while they are small. The plant soon develops a deep taproot and a thick, woody rootstock, so move it to its final position early rather than later.
Spring-sown seedlings usually flower in their first year. Autumn seedlings stay as leafy shoots through winter and flower the following spring or summer. Space plants so each clump has room to spread, since a single plant can be up to 0.5 m (20 in) wide.
Cause: slugs and snails, to which the plant is susceptible. Fix: protect seedlings and young shoots, especially in damp weather.
Cause: powdery mildew, which affects plants in dry soil. Fix: water in dry spells and avoid crowding.
Cause: abundant seed, and regrowth from root and crown pieces left after digging. Fix: cut flowers as they fade and remove whole roots when clearing a plant.
Cause: the species germinates mainly in the cooler seasons. Fix: resow in spring or autumn.
Bladder campion grows in full sun or dappled shade and prefers neutral to alkaline soil. It is very hardy, surviving -15 to -20 °C (5 to -4 °F).
Cutting stems down after the flowers fade prolongs flowering.
Where it is grown as a green, pick young leafy shoots in spring before flowering stems form.
Plants reach 0.5-1 m (20-40 in) tall and take two to five years to reach full size. The woody rootstock is long-lived, so choose a permanent spot.
Seed ripens in small capsules that open by six teeth at the top. Cut stems as the capsules turn brown, dry them in a paper bag and shake out the seed; flowering runs from summer into autumn, so collect over several weeks.
Grow hardy bladder campion for its lantern-like flowers and tender spring shoots.
Spring or autumn. The RHS advises sowing in containers in a cold frame in autumn; in the wild most seedlings appear in spring and autumn. In hot climates, sow in the cool season.
Usually, if sown in spring. Autumn-sown seedlings stay leafy through winter and flower the next year.
Yes. Stridolo and sculpit are names used for the same species, Silene vulgaris, when its young shoots are grown as a green.
Yes. It is a long-lived perennial that dies back to a woody rootstock and regrows each year, and it is hardy to about -15 to -20 °C (5 to -4 °F).