Sedirea japonica is a rare yet popular species of orchid. Known for its stunningly fragrant flowers, it adds a special touch to any room.

Growing it isn’t necessarily easy since it requires rather stringent conditions.

However, in this guide, our expert gardeners have detailed everything you need to know to ensure a healthy bloom.

What Is Sedirea Japonica

Sedirea japonica, also known as Phalaenopsis japonica and Nagoran (orchid of Nago), is a subtropical orchid species native to Japan and Korea. It is an epiphyte with a small, compact shape, deep green foliage, and fragrant flowers. When grown indoors, it usually reaches a maximum height of 20 inches (40 cm).

This orchid is one of the only two species belonging to the Sedirea genus. This genus was first described in 1974 by botanists Leslie Andrew Garay and Herman Royden Sweet. The name Sedirea is the backward spelling of the word “Aerides,” which is a genus of orchids that this plant previously belonged to.

Sedirea japonica’s main feature is its inflorescence. The plant produces a stem about 8 inches (20 cm) long, with clusters of 6 or 10 flowers. These small blooms are 1.6 inches (4 cm) in size, pale green or yellow, with light pink markings. It typically blooms in spring and summer, and the flowers are very showy and pleasantly fragrant.

– Types of Sedirea Japonica

There are several varieties you’ll come across in Sedirea japonica culture. Popular cultivars are Sedirea japonica Minmaru, Seigyokumaru, Fusamaru, and Minmaru Shima (a variegated version of the Minmaru cultivar).

Sedirea japonica can be grown in containers and even hanging baskets. One growth method that works wonders for this plant is having it mounted on a piece of wood. In Japan, they are usually potted in sphagnum moss using a traditional display method called fūkiran.

Sedirea Japonica Care Guide

Sedirea japonica can be a high-maintenance plant, which makes it not quite beginner-friendly. But don’t let that put you off. In this guide, we’ll walk you through all the essential tips and tricks that will help you better understand its growing requirements.

Let’s start with the most important aspect of caring for this unique orchid.

– Soil Requirements

Keeping your Sedirea japonica healthy and thriving relies heavily on the type of substrate used. This plant needs a very well-draining, aerated, and moisture-retentive substrate. As such, universal plant mixes are not suitable.

The ideal potting mix for Sedirea japonica should consist of orchid bark, perlite, and sphagnum moss. The bark will provide plenty of aeration to the roots, while the moss and perlite will help with drainage and moisture retention. You can also add a bit of horticultural charcoal to the mix to prevent any fungal problems while improving drainage.

– Light Requirements

Sedirea japonica needs bright indirect light for healthy growth. Like most orchid species, it is an epiphyte, which means it grows on trees in its natural habitat. As a result, it has adapted to receiving dappled shade and indirect light filtered through the trees’ foliage.

Place your Sedirea japonica in a room with eastern or western exposure away from the windows. Direct sunlight will scorch the plant’s leaves and cause the potting mix to dry out too fast.

– Temperature Requirements

The Sedirea japonica temperature requirements will vary depending on the season. In summer, the ideal temperature range is between 77 F and 88 F (25 C to 31 C).

During the winter months, the plant enters a period of dormancy, which allows it to rest in between blooming seasons. To trigger dormancy, you will need to reduce the temperatures in winter to about 46 F to 55 F (8 C to 13 C).

You must allow your Sedirea japonica to rest in winter. If the temperatures are kept high and the plant does not enter dormancy, it will continue to bloom, gradually reducing its lifespan due to exhaustion.

– Water Requirements

Throughout spring and summer, Sedirea japonica will need to be watered frequently and abundantly. The moss in the substrate should feel moist to the touch at all times. Use the soak and drain method as often as necessary and make sure that the roots are never sitting in water.

It’s a bit of a balancing act. This orchid is not drought tolerant, yet it can be very susceptible to rot, which is why a well-draining potting mix is just as important as how often you water it.

Gradually cut down on watering from late autumn until early spring. Sedirea japonica enters a period of dormancy in winter, and cold temperatures combined with frequent watering will result in rot. Rather than watering it, simply mist the substrate every day. Just give it enough to keep the moss and the roots from drying out.

Never use ice cubes to water your Sedirea japonica. Even though some guides recommend this for orchids, ice cubes will only shock the plant’s roots, causing it to wilt.

– Humidity Requirements

Sedirea japonica grows best in humidity levels ranging from 60 to 80 percent. We recommend using a humidifier to meet the plant’s needs or placing it on top of a pebble tray. You can also mist the leaves daily, yet avoid spraying water on the flowers. This can cause spots and other fungal problems.

Apart from humidity, your Sedirea japonica will also need good air circulation around the leaves and stems. The easiest way to ensure this, without losing too much humidity, is by placing a small electric fan next to the pot. Avoid exposing the plant to hot or cold drafts as they may shock it.

– Fertilizer requirements

Sedirea japonica will need fertilizer applications twice a month throughout spring and summer. You can use any orchid fertilizer for this, and make sure that you dilute it to half the strength recommended on the label. Alternatively, you can use a diluted, nitrogen-rich solution in spring and summer and switch to a phosphorus-rich fertilizer in autumn.

Always check that the substrate is moist before feeding the plant. Otherwise, the roots will suffer from fertilizer burn. From late autumn until the end of winter, the plant enters its dormancy period. During this time, your Sedirea japonica won’t need any fertilizer applications.

– Pruning and Maintenance

Sedirea japonica requires very little pruning. This plant doesn’t have many leaves, so avoid trimming them unless they are turning brown or are infested with pests. Use a sharp pair of scissors for pruning and sterilize the blades with rubbing alcohol after each cut.

After the blooms have wilted, you can remove the flowering stalk. Trimming the spent flowers will encourage the orchid to bloom again. Make sure that the cut on the flowering stem isn’t made too close to the nodes, as this may prevent the plant from flowering.

On average, Sedirea japonica will bloom for five or six seasons. You can try to prolong the plant’s life by allowing it to rest during winter. However, this orchid has a short lifespan, so after around four or five years, it’s worth propagating it so that you can enjoy it for longer.

– Repotting Sedirea Japonica

While the Sedirea japonica growth rate is rather slow, you will still need to repot it once a year. The reason for this is the substrate it’s growing in. Moss and pine bark will decompose over time, gradually becoming a breeding ground for fungal problems. The best time to repot Sedirea japonica is in spring, when the plant enters its growth period.

Make sure to remove all of the old potting mix from the roots, then plant the orchid in a fresh substrate. If the roots have grown too big, move the plant to a container that’s one size bigger. Always ensure that the container has drainage holes at the bottom.

When repotting your Sedirea japonica, take a moment to inspect the roots. Healthy roots are firm to the touch, and they should be white or light green. If you notice any roots that are brown or soft to the touch, trim them with a sterilized blade.

Sedirea Japonica Propagation

Sedirea japonica is a rare plant, so trying to propagate it can be very tempting. The easiest way to propagate this orchid is through stem cuttings that have developed a Keiki – a baby orchid produced asexually by the mother plant.

Here’s what you’ll need to propagate your Sedirea japonica through Keiki cuttings:

  • Start by identifying the Keiki. It should look like a smaller version of the orchid, with its own set of leaves and aerial roots growing on the stem.
  • If the Keiki already has at least two leaves and four aerial roots, you can remove it from the mother plant. Otherwise, give the Keiki a bit more time to grow.
  • Use a sterilized pair of scissors to cut the stem the Keiki is growing on. Cut just above the closest growth node on the stem, leaving a spike that’s at least 1 inch (2.5 cm) attached to it.
  • Fill a small pot with orchid bark and cover the aerial roots with the bark. Keep the cut stem above the potting mix to prevent any rotting.
  • Lightly water the bark and make sure that the medium does not dry out at any time.
  • Give the new plant lots of humidity and keep it away from direct sunlight.

– Seed Propagation

You can also use Sedirea japonica seeds for propagation. However, growing any orchid species from seeds is very difficult. The main challenge is pollinating the flowers, then waiting for the seed pods to form.

It’s also best that you sow seeds collected from green pods rather than dry seeds. This way, they have a higher chance of germinating and are less likely to be contaminated with pathogens.

Even if you find viable Sedirea japonica seeds, they will take a very long time to grow. You can expect to wait anywhere between eight months to two years before the plant is fully developed and at least another year before the new orchid will bloom. The process is not easy for beginners, which is why we recommend propagating this plant from Keikis.

Conclusion

Sedirea japonica might not be the easiest plant to grow at home, but it’s well worth the effort. Follow our care guide, and you can’t go wrong!

Let’s do a quick recap:

  • A very well-draining potting mix, high humidity, and indirect light are essential for healthy growth.
  • Each stem produces up to 10 small, fragrant flowers throughout spring and summer.
  • Sedirea japonica is a short-lived plant and will typically bloom for around five or six seasons.
  • Allowing the plant to rest during winter will encourage it to bloom the following year.
  • The easiest way to propagate this orchid is through Keiki cuttings.

Caring for Sedirea japonica may seem like a challenge at first. But with our tips for healthy growth, your orchid will continue to thrive and flower for many years.

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