Common Camellia (Camellia japonica)

While some houseplants are highly useful, others are pretty and showy. However, some houseplants are both. Camellia Japonica aka Japanese Camellia falls into this distinctive category. Nearly all parts of this showy flower plant carry medicinal properties and are used for their anti-viral, anti-oxidant and anti-inflammatory properties. Although slow growing, this evergreen shrub is a great addition to any garden.

I. Appearance and Characteristics 

Camellia japonica, known as common camellia, or Japanese camellia, is a species of Camellia, a flowering plant genus in the family Theaceae. There are thousands of cultivars of C. japonica in cultivation, with many colors and forms of flowers. Despite its common name, it is native to China, not Japan. The cultivation of Camellia japonica also started in China. Its widespread cultivation can be traced back to the Song Dynasty, when 15 varieties of Camellia japonica were recorded in literature. It was later introduced to Japan. It grows in forests, at altitudes of around 300–1,100 meters (980–3,600 ft).

Camellia japonica is a flowering tree or shrub, usually 1.5–6 meters (4.9–19.7 ft) tall, but occasionally up to 11 meters (36 ft) tall. Some cultivated varieties achieve a size of 72 m2 or more. The youngest branches are purplish brown, becoming grayish brown as they age.

The alternately arranged leathery leaves are dark green on the top side, paler on the underside, usually 5–11 centimeters (2.0–4.3 in) long by 2.5–6 centimeters (1.0–2.4 in) wide with a stalk (petiole) about 5–10 millimeters (0.2–0.4 in) long. The base of the leaf is pointed (cuneate), the margins are very finely toothed (serrulate) and the tip somewhat pointed.

C. japonica leaves are eaten by the caterpillars of some Lepidoptera, such as the engrailed (Ectropis crepuscularia).

Flower

In the wild, flowering is between January and March. The flowers appear along the branches, particularly towards the ends, and have very short stems. They occur either alone or in pairs, and are 6–10 centimeters (2.4 – 3.9 in) across.

There are about nine greenish bracteoles and sepals. Flowers of the wild species have six or seven rose or white petals, each 3 – 4.5 centimeters (1.2 – 1.8 in) long by 1.5 – 2.5 centimeters (0.6 – 1.0 in) wide; the innermost petals are joined at the base for up to a third of their length. (Cultivated forms often have more petals.) The numerous stamens are 2.5 – 3.5 centimeters (1.0 – 1.4 in) long, the outer whorl being joined at the base for up to 2.5 centimeters (1.0 in). The three-lobed style is about 3 centimeters (1.2 in) long.

The Japanese white eye bird (Zosterops japonica) pollinates Camellia japonica.

Fruit

The fruit consists of a globe-shaped capsule with three compartments (locules), each with one or two large brown seeds with a diameter of 1–2 centimeters (0.4–0.8 in). Fruiting occurs in September to October in the wild.

II. How to Grow and Care

Sunlight

Japanese camellias produce the best blooms in light shade. They need protection from the intense, direct afternoon sun.

Temperature and Humidity

Sudden temperature changes are detrimental to growing Japanese camellia. The plant tolerates temperatures as low as 10 degrees F but only for short periods.

Select the site carefully and ensure it has adequate shelter against cold winter winds.

Watering

Japanese camellias need consistent moisture (but not to the point of saturation) to produce healthy abundant blooms. Mulching around the base helps retain moisture.

Soil

These shrubs have very specific soil requirements. A well-drained, nutrient-rich, moist, and slightly acidic soil is a must for successfully growing Japanese camellia. If your soil does not meet these conditions, grow it in a container.

Fertilizing

If you want to see many healthy blooms on your Japanese camellia, apply a high-potassium fertilizer monthly during the summer. In the spring, use a slow-release nitrogen-rich fertilizer, as this will promote healthy, dark foliage. It’s even possible to find camellia-specific fertilizers in some garden centers. For the amounts to use, follow product label instructions.

Pruning

Unless you want to train your Japanese camellia, it won’t need much pruning, and too much may spoil the attractive natural shape. Only remove dead or damaged branches or long, heavy shoots right after the flowering season. This stimulates branching and prevents the accidental removal of new flower buds.

Propagation

You want to ensure your Asian beauty is always with you in the home or garden. So, you can do this using seed or cutting propagation.

Stem Cutting Propagation

The best time for stem cutting is late spring or early summer. First, choose a healthy stem with six leaf nodes and cut behind the 6th one. Next, remove all the nodes except for the top three.

You can dip the cutting in a rooting hormone before you plant it. Get a container ready filled with coarse sand and peat moss. Pot the cutting and water to keep the soil moist while removing excess drained water.

Place your potting medium in a warm spot with bright indirect light and cover it with a plastic bag. Open the plastic bag daily to mist your cuttings using distilled water. Remove any cuttings that look as if it is musty or dead.

You should notice a root system forming after three months, and once this happens, you can transplant each cutting into its pots.

Seed Planting

If you want to breed your shrub with seeds, we recommend using ones from a garden center. Or you will need to trigger the formation in your shrubs. You can do this as follow:

• Take a brush and go over the pistil several times.
• If the insemination is successful after the flower, it bears green fruits.
• After the fruits ripen, the shell breaks open, and you may get up to 12 dark brown seeds.
• You must break the seed’s dormancy to expose it to cold for a few weeks.
• You can place the seed on the lower shelf in your refrigerator for 28 days.
• During this time, the grains loosen from the germination capacity.
• Fill a pot with soil and spread the seed while covering them with a small amount of ground.
• Spray the soil but avoid stagnant moisture and keep them in a cool yet light location.
• Also, avoid direct sunlight; you should notice new growth after two weeks.

• Once this happens, you can take a spoon to remove each germ bud to transplant into their pots.

Potting and Repotting 

Camellias thrive in pots. The container will require ample drainage holes and a well-draining soil mixture, such as a camellia or azalea potting mix. You can also make your own mix from bark, sand, sphagnum moss, pumice stone, and compost. 

Like all container plants, potted Japanese camellia needs more frequent watering than the shrub in the landscape. However, it does not tolerate wet feet or soggy soil.

Fertilize it regularly between April and September, except when temperatures are above 90 degrees F.

Repot the plant every two to three years to a larger container with fresh potting mix as the roots and plant outgrow the container.

Overwintering

In a southern climate with mild winters, Japanese camellia can remain outdoors during the winter. If you planted the shrub in a protected spot, all you need to do is cover the soil with a thick, mounded layer of dry leaves and pine needles to insulate the roots from freezing temperatures. Camellias that are in a more exposed location should be covered with a burlap or canvas protective fence until spring arrives.

In northern areas, Japanese camellia should be grown in a container and overwintered indoors. Keep it in a controlled environment where temperatures do not exceed 55 degrees F, otherwise, flower buds will drop. Avoid excessive humidity and sudden temperature changes.

Pests and Diseases

Common Pests & Plant Diseases

Japanese camellias are susceptible to fungal diseases. Shrubs affected by petal blight fungus have petals that are browning from the edges to the center. Remove all the diseased plant parts promptly to contain the spread of the fungus. Other potential diseases are leaf spot, anthracnose, viruses, black mold, cankers, and root rot.

Pests seeking out Japanese camellia include aphids, planthoppers, as well as spider mites. Scale insects sometimes infest the plant in milder regions, causing premature bud drop. Preventing your plant from becoming drought-stressed with enough water in the dry season helps to minimize this problem.

Common Problems 

• Bud Drop

Some flower bud drop is normal for Japanese camellia but premature or excessive bud drop is often a sign of insufficient moisture during the summer months, when precipitation is commonly low. Make sure to keep the soil moist but not saturated.

• Yellow Leaves

If you notice the leaves on your shrub are turning yellow with green veins, it could be a sign that the soil is too alkaline. Do a soil test to determine the pH and if it turns out to be above 6.0, add iron chelates to the soil, or use a fertilizer formulated to correct iron deficiency.

III. How to Get Japanese Camellia to Bloom

• Bloom Months

The flowering time depends on the variety. Japanese camellia blooms as early as October and as late as March.

• How Long Does Japanese Camellia Bloom?

The flowers usually last three to four weeks.

• What Do Japanese Camellia Flowers Look and Smell Like?

The flowers of Japanese camellia grow in clusters. Depending on the variety, they range considerably in size, from miniature (1.5 inches) to huge (5 inches), as well as in shape (single, double, etc.) and color. Not all varieties are fragrant; those that are grown for their fragrance have a sweet, floral smell that is often likened to jasmine.

• How to Encourage More Blooms

Poor flowering may be caused by too much sun and frigid temperatures. In addition to providing the proper temperature and light conditions, applying fertilizer for acid-loving plants that is low in nitrogen and high in potassium is key to promoting flowering.

• Caring for Japanese Camellia After It Blooms

If your camellia needs pruning, do this promptly after the bloom, which avoids accidentally removing next year’s flower buds. 

• Deadheading Japanese Camellia Flowers

Removing the faded flowers is optional. It will keep the plant neat and makes room for new flowers but it does not encourage the plant to produce more flowers. In fact, the plant often produces more flower buds than it has energy to open, and those buds naturally drop. To support this process, remove all but one bud from the cluster, which may also help to increase the bloom size.

IV. Uses and Benefits

• Medicinal uses

Largely exploited for ornamental purposes, this plant has great medicinal properties. The leaves and flowers have anti-viral, anti-oxidant, neuroprotective, hypolipidemic, anti-obesity and anti-inflammatory properties and have been used as a local medicine in its native areas. In traditional Japanese, Chinese and Korean medicines the plant is used for the treatment of stomach illness, bleeding and inflammation. Its oil, along with sesame seed oil, is used for burns and scalds. The plant is also believed to have anti-cancer properties.

• Ornamental uses

Japanese camellia is an evergreen woody tree or shrub commonly found in gardens. It is prized for its rich foliage and long-lasting glorious blooms. It has dense foliage and is often planted as a shade-providing flowering screen. Japanese camellia is often used in Japanese-style or Pollinator gardens. Plant Crocuses, Japanese Spurge, or Tulips for color contrast.

• Artistic value

Chinese poets left behind many poems praising the Japanese Camellia