Campanula grandiflora – Platycodon cultivation


There Campanula grandiflora, Platycodon grandiflorus, is an ornamental plant grown in the garden and in pots due to its abundant and prolonged summer-autumn flowering.


General characteristics Campanula Grandiflora Platycodon

There Campanula grandiflora commonly known as Japanese Campanula is a plant of Asian origin that belongs to the vast family of Campanulaceae such as the common bluebells and the creeping bell.

There plant herbaceous and perennial, on average 50 cm tall, it has erect stems, rich in oval or lanceolate leaves with toothed margins.

The leaves they are alternate, hairless and green in color with beautiful bluish reflections.


Read also: Campanula rapunculus – Raponzolo

Numerous appear on the slender and erect dark green stems during the flowering period flowers star-shaped, with 4 or 5 lobes, white, pink, blue or lilac.


THE flowers still in bud they look like inflated balloons and are similar to small Chinese lanterns.



Platycodon plants produce abundant flowering from early summer through late autumn.


Platycodon cultivation – Campanula grandiflora


This flowering plant, while preferring bright and sunny places, also grows well in semi-shaded ones. It bears very cold winter temperatures.


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The cultivation soil must be loose, peaty, rich in organic substance, moist but always well drained.


The Platycodon should be watered regularly from the vegetative restart until the end of flowering also in relation to the climate and the fall of the rains. If it is very hot, it is better to abound frequently, trying to always leave the soil moist. In winter, irrigation should only be done if the cultivation soil is too dry.



To obtain a copious flowering, administer once a month, from the vegetative restart onwards, from March to September, a specific liquid fertilizer for flowering plants diluted in the watering water. Alternatively, use a slow release granular fertilizer, to be spread around the plants every 3-4 months. Using a fertilizer that is richer in potassium (K) and low in nitrogen (N) will stimulate greater flower production.

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Platycodon - Pot cultivation

Campanula grandiflora: cultivation in pots

Platycodon especially the dwarf varieties are easy plants to grow in pots on balconies sheltered from strong winds and in a partially shaded area.

  • To obtain lush plants, the container must be deep enough to ensure regular development of the long fleshy roots.
  • A thick layer of expanded clay covered with a layer of soil suitable for flowering plants, mixed with sand, should be placed on the bottom of the pot.
  • The plant is placed in the center; more soil is added and compacted well all around filling all the gaps.
  • Finally, the soil is wet and a level teaspoon of granular fertilizer for flowering plants is spread on the surface. Subsequent waterings are to be done regularly, always avoiding that the soil dries up completely, but never overdoing it.


Platycodon should be repotted every two years, taking care not to damage the roots, which wither and rot very easily.


Multiplication of Platycodon

Campanula grandiflora propagates by seed, by cutting or by division of the tufts.


The sowing is done in the month of August, in the soil composed of three parts of fertile soil and one part of coarse sand. The seeds must be made to adhere well to the soil which must always be kept moist until germination.

The container should be placed in a shaded area with a temperature not lower than 15 ° C.

You cover the tray with a clear plastic sheet.

After germination, after about 3 months, the plastic sheet is removed and the container moved to a brighter and well-ventilated place.

When the plants are large enough they should be transplanted in the ground or in single pots and treated as adult plants.

Multiplication by cuttings

It is carried out in early spring.

Cuttings with a length of about 10 cm are taken by cutting them obliquely immediately under the node.

The lower leaves are eliminated, then to promote rooting the cut part must be treated with specific rooting hormones, the DIY rooting hormone obtained from the twigs of Willow is also excellent.

Campanula grandiflora cuttings must be buried in a soil composed of peat and coarse sand, kept constantly humid until new shoots appear.

The container is covered with a transparent plastic sheet and placed in a shady place at about 15 degrees.

When the first shoots appear, it means that the cuttings have rooted and the container must be moved to a bright area in order to encourage the growth of the new seedlings.

When the plants are easy to handle, they are transplanted into the final pot or into the garden.

Multiplication by division of the tufts

The division of the tufts, on the other hand, should be practiced in spring and only on well-branched plants. The tufts must be buried immediately in the fresh and loose soil.


Planting of Campanula grandiflora

The new campanula grandiflora seedlings should be planted in spring in the soil that is worked in depth and free from weeds and mixed with a good quantity of mature manure and a few handfuls of fine and coarse river sand.

The seedlings must be planted at a distance of 20- 40 cm from each other, taking great care not to damage the delicate and sensitive roots. After planting, irrigate abundantly for at least 2 weeks, avoiding water stagnation. Once implanted, campanula grandiflora plants must be left undisturbed in the same place for at least 4 years as they suffer from displacements.


Pruning of the Japanese Campanula

Pruning interventions are limited to the elimination of dry stems as the aerial part of Campanula grandiflora is completely renewed in spring. Gradually even the withered flowers are eliminated. At the end of the season, some flowers are dried directly on the plant if you want to collect ripe seeds to be used for sowing in the following spring.


Pests and diseases of the Japanese Campanula

It is a very resistant plant and rarely suffers from the attack of various diseases and parasites such as aphids. It suffers from root rot due to water stagnation.


The true enemies of the bluebell are snails that devour its leaves and the most tender shoots.

Cures and treatments

It does not require special care. Snails and slugs can be kept at a distance with beer traps and in severe cases, by using snail killers.


Is Campanula grandiflora poisonous?

This beautiful ornamental plant is non-toxic to humans and pets. The flowers and roots are edible. The flowers are used to decorate salads and desserts while the roots in oriental medicine are used for therapeutic purposes for the treatment of various ailments.


Campanula grandiflora plants are used for ornamental purposes in gardens to create flower borders, in pots to embellish balconies and terraces. Cut flowers are used in flower arrangements while dried flowers are used in potpourri.

Campanula: language of flowers

In the language of flowers this plant has both positive and negative meanings.

Symbolizes perseverance and hope.

In Scotland it is regarded as the Devil’s bell.

In many other countries, the flowers are called bells of the dead because their tinkling was second felt by the people just before they died.

Platycodon-Campanula grandiflora


The scientific name Platycodon which derives from the ancient Greek πλατύς (broad) and κώδων (bell) refers to the shape of the plant’s flowers.

Campanula grandiflora owes its name to the fact that its large, pendulous flowers resemble a bell that moves with every breath of wind.

Platycodon photo gallery



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