Plumbago auriculata: location, care & winter hardiness of leadwort

Plumbago auriculata is a rare beauty thanks to its sky-blue, continuous flowering. Special attention must be paid to the correct location and care of this South African ornamental plant.

Cape plumbago (Plumbago auriculata) from the Plumbaginaceae family has become an indispensable part of the potted plant assortment. The ornamental shrub forms beautiful, sky-blue flowers that transform balconies and terraces into a floral oasis.

Plumbago auriculata: origin and characteristics

The ornamental cape plumbago shrub originates from the tropics and subtropics of South Africa, where it thrives in sunny, warm bushes. In its native habitat, i.e. under optimal site conditions, the plumbago is evergreen. At our latitudes, however, it loses its foliage over the winter. Plumbago can be cultivated as a bush or climbing plant and is suitable for containers. The phlox-like, five-petalled flowers of the plumbago in sky or azure blue, and occasionally also in white, provide a summery lightness. Plumbago flowers can be admired during their long flowering season from May to October. During this period, the ornamental shrub provides an excellent source of nectar for many insects, especially butterflies. The elongated 4 to 7 cm leaves are medium to pale green and make the blue flowers shine even brighter. In a frost-free habitat, cape plumbago can grow between 2 and 4 metres in height. In areas like ours where winters are cold and frosty, however, it only grows between 50 and 200 cm tall.

Tip: The name plumbago is derived from ‘plumbum’, the Latin word for lead, and refers to the popular belief that plumbago can cure lead poisoning.

The most beautiful varieties

There are many beautiful varieties of cape plumbago that differ in growth height and flower colour. The most beautiful varieties of cape plumbago are presented below:

• ‘Alba’: This variety has bright white flowers on its overhanging branches. It can reach a stately height of around 50 – 150 cm.

• ‘Royal Cape’: Flowers in a striking cobalt blue adorn this variety. It has a growth height of between 1.5 and 2 m.

• ‘Caerulea’: This variety is known for its sky-blue flowers and compact growth height of about 50 cm.
• ‘Indica’: The flowers of this variety are bright red and form a contrast to the otherwise well-known blue plumbago varieties. It reaches 80 to 200 cm in height.

Planting Plumbago auriculata: when and where?

Plumbago is a frost-sensitive plant and should therefore only be cultivated in containers in spring after the frosts have passed, as plumbago is not suitable for cultivation in beds. Plumbago prefers a sunny and warm location. A 20-litre planter is suitable for planting. Drainage is very important for potted plants as plumbago does not tolerate waterlogging. The best way to do this is to fill the planter with a layer of gravel, sand or expanded clay. Ideally, the substrate for the plumbago is a well-drained, nutrient-rich and compost-rich potting soil such as our Plantura Organic Flower Compost.

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(5/5)

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The main care tips

Plumbago is a low-maintenance ornamental plant. Ensure sufficient watering on hot summer days. It is best to water in the morning when evaporation is at its lowest. Water immediately if you notice that the plumbago leaves are wilting. Fertilisation at the beginning of new growth is important for supporting the ornamental shrub’s growth. Our Plantura Liquid Flower Food is ideal for this purpose. This can be administered every fortnight from April to September via the irrigation water. The fertiliser provides the plumbago with the necessary nutrients, which can be better utilised by adding microorganisms.

Liquid Flower Food, 800ml

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• Perfect for all flowers & balcony plants
• Liquid fertiliser for a lush blossom throughout the season
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Annual repotting of the ornamental shrub in fresh substrate will reward you with abundant flowering. Any faded flowers should be regularly removed. In spring or during the growing season, the shoots can be shortened by up to 10 cm to promote intensive flowering and bushy plant growth.

If you want to keep plumbago as a climbing plant, you can use climbing aids in the form of a trellis or a support pole.

Tip: Cape plumbago is susceptible to pests such as aphids (Aphidoidea), particularly in spring. However, Californian thrips (Frankliniella occidentalis) can also infest plumbago and suck out the young tissue from leaves and flowers.

Is Plumbago auriculata frost-resistant?

Plumbago tolerates temperatures down to – 5 °C and so is only slightly sensitive to frost. The container should therefore be protected from excessive frost. It is best to place the plant in a cool, dry and preferably dark room at a temperature of about 10 °C.

Propagating Plumbago auriculata

Propagation of cape plumbago is mainly possible with cuttings or seeds:

Propagation from cuttings

Plumbago can be propagated without much effort via cuttings. In the following, we show how best to proceed when propagating from cuttings:

• From April to June, cut off shoots about 10 – 15 cm long and remove the flowers and leaves.
• Fill the pot with a low-nutrient, permeable growing medium such as our Plantura Organic Herb & Seedling Compost.
• Insert shoots 5 – 7 cm deep into the substrate.
• Ideally, put a transparent cover over the cuttings and keep the substrate moist.
• Ventilate the plumbago regularly, otherwise mould will form.
• Place the pots in a bright place at a temperature of about 20 ° C.
• The first roots will form after around 4 weeks.

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Propagation from seed

As cape plumbago is used to a different climate, a few points should be taken into account when sowing:

• Sowing is ideally done in spring.
• Choose a high-quality growing medium such as our Plantura Organic Herb & Seedling Compost.
• This should be mixed with coarse sand to improve drainage, prevent waterlogging and allow more air to reach the roots.
• Place the seeds in the growing medium and cover lightly with substrate.
• The temperature should remain constant between 18 – 24 °C.
• The substrate must always be kept moist, preferably with rainwater from a spray bottle.
• Germination occurs after about 4 – 6 weeks.

Tip: Even a single drying out can destroy the seeds. Pay particular attention here to constant moisture in the substrate.

Is Plumbago auriculata poisonous?

Plumbago is classified as slightly toxic and so the consumption of plant parts should be avoided. However, little is known about the toxic ingredients; in everyday handling, plumbago poses no danger.

Cape plumbago impresses with its delicate flowers in sky blue or white. At the same time, there are other unusual pot plants such as quillwort (Cuphea), which are available in many different shapes and colours.