The low growing Ceratostigma genus can be a half hardy or hardy perennial.
Ceratostigma is also known by the common names of Leadwort and Plumbago.
Ceratostigma tends to flower from summer to autumn with deep blue blooms or pink and has beautiful red or bronze leaves when flowering.
Due to their small size leadwort and plumbago make ideal plants for rockeries or as a fill in plant for stone walls.
Ceratostigma plumbaginoides flowers and foliage by Harveyharrison and Wallygrom.
Common Names: Leadwort, Plumbago.
Life Cycle: Hardy perennial. Half-hardy perennial.
Height: 12 to 40 inches (30 to 100 cm).
Native: Asia, Africa.
Growing Region: Zones 5 to 10.
Flowers: Summer through autumn.
Flower Details: Blue, red-purple, pink.
Foliage: Leaves change colour in the autumn - Green to Bronze, Blue-green to Crimson. Simple. Spiral.
Sow Outside: Cover seed. Sow hardy perennials at the beginning of spring - before the last frost, or towards the end of autumn. Sow half hardy perennials following the last frost. Spacing 12 to 18 inches (30 to 45 cm).
Sow Inside: Germination time: one to three months. Temperature 60°F (16°C). Mix seeds in moist sand, place in a freezer bag, then stratify by refrigeration for five or six weeks. Sow the stratified Ceratostigma seeds about three months before they are due to be transplanted; the beginning of spring or autumn for hardy species; half hardy plants should be transplanted in the spring as soon as temperatures do not drop below 50°F (10°C).
Requirements: Full sunlight or partial shade. Grows in most soils, but grow Ceratostigma in rich, organic soils that have good drainage for best results. Regular light watering. Cut back to the ground in autumn. Propagate: by dividing in late autumn (hardy) or after the last spring frost (half hardy).
Ceratostigma require cold to germinate, so should therefore be sown out before the last frost of spring, or in the autumn. Seeds should be covered. Ceratostigma prefers to grow in partially shaded or sunny parts of the garden and will grow in most soils, though best results will be got in an organic soil.
If you want to grow Leadwort or other Ceratostigma species from seeds indoors first then they should be imbibed by placing the seeds (within soil) in a black bag, then placing in the fridge for five or six weeks. Seeds should then be sown out at a temperature of 15 Celsius; they normally take about one to three months to germinate.
Ceratostigma seedlings should be transplanted in early spring with a spacing of 30 to 45 cm. Hardy species of Ceratostigma can also be planted out in the autumn. Plants should be regularly watered, but do not drench them; they should be cut back in the autumn.
I hope that you enjoyed this guide on how to grow Ceratostigma plants. Updated September 2020.