Noble dendrobium

Noble dendrobium: how do you recognise it?

Habit

Epiphytic orchid with upright, jointed canes of 30–60 cm, forming a clump 30 cm wide.

Leaves

Narrow, lance-shaped, 5–10 cm, along the cane; some of the leaves drop in winter.

Flower

Clusters of 2–3 flowers, 5–8 cm across, at the nodes, white with purple-pink tips and a dark purple throat, from February to May.

Scent

Soft and pleasant, strongest by day.

Roots

Thick aerial roots that grip bark; they dislike wet feet.

Flowering: February–May · Plants: April–May

Why grow it?

• Abundant flowers from February to May, along the whole cane.
• The flowers have a soft fragrance and last for weeks.
• Flowers year after year on the same plant if given a cool rest.
• Stays compact: 60 cm tall and 30 cm wide.
• May go outdoors in summer: the plant grows strongly for it.

Noble dendrobium: where does it grow best?

• Plenty of light with some sun: a south, east or west window; in summer outdoors in partial shade.
• Coarse, airy orchid bark, if you like mixed with some sphagnum moss or perlite; acid.
• Regularly moist in the growing season, drier in autumn and winter.
• Summer 20–30 °C, winter cool (10–15 °C), never below 8 °C.
• Give the roots air: a small pot with coarse bark, in a bright spot with fresh air.

Light

Sunny or bright, out of direct sun

Potting soil

Airy, humus-rich compost

Acidity

Acid

Watering

Moderately

Size

0.6 m tall, 0.3 m wide

Temperature

Minimum 8 °C

Goes well with

• Coelogyne: An orchid with the same cool winter rest.
• Cymbidium: Likes a cool winter and also flowers in spring.
• Moth orchid (Phalaenopsis): Another orchid for the warmer room, using the same bark as potting mix.
• Ferns: They keep the air around the plant more humid.

Noble dendrobium: when and how to plant it?

Plant in April–May.

1. Repot in April–May, after flowering, as soon as the new shoots appear at the base. No more often than every 2–3 years.
2. Choose a small pot only slightly bigger than the plant; it flowers best when the roots fill the pot.
3. Use coarse orchid bark, if you like mixed with a little sphagnum moss or perlite, which holds moisture but drains well.
4. Fix the plant firmly, if need be with a stake, and let the canes stand above the bark.
5. Water sparingly for the first two weeks and only mist the bark, so that damaged roots can heal.

Care

Water

From April to September water regularly and generously, as soon as the top of the bark is dry. From autumn less, and in winter hardly at all, until the buds appear. Use rainwater or low-lime water.

Feeding

From April to August give half-strength orchid fertiliser every week or two. Stop from September.

Light

Plenty of light with some sun helps to set buds; in summer give partial shade outdoors or behind a curtain to prevent scorching.

Cool rest

From September to January keep it cooler (10–15 °C) and drier: that is the trigger for forming flower buds.

After flowering

Resume watering, start feeding again and leave the old canes in place: they can still flower for two to three years.

Tip: Give it a bright spot in summer, and feel free to put it outdoors in partial shade. Keep it cool (10–15 °C) and drier in autumn: without that cool rest no flower buds form.

Noble dendrobium: when to prune it?

When: It is not pruned. Only cut off completely dried canes and faded flowers, in spring after flowering.

How:

• Leave green and still firm canes in place: older canes flower again too.
• Only cut a cane off at the base when it is completely yellow and shrivelled.
• Cut off faded flowers or flower sprays.
• Disinfect the scissors with alcohol between plants.

Pruning calendar and basic rules

Propagation

Keikis

Small plantlets sometimes grow on old canes. Detach them when they have their own roots of 3–5 cm and pot them up in fine bark in a small pot.

Division

In April–May, when repotting: split the clump into pieces with at least 3 canes.

Cane cuttings

Cut an old, leafless cane into pieces of 2–3 nodes and lay them on damp sphagnum moss, warm and bright; keikis grow from the nodes.

Noble dendrobium: how does it get through the winter?

• Not hardy: it needs at least 8 °C and overwinters best cool and bright at 10–15 °C.
• Water little in winter, about once a fortnight, so that the canes do not wrinkle too much. Give a little more water as soon as the buds appear.
• It is normal for the plant to lose leaves in winter; keep it cool and bright, not above the heating.

Diseases and pests

• No flowers: Usually too little light or no cool, drier autumn. Give plenty of light in summer and keep it cooler and drier from September to January.
• Keikis instead of flowers: Too warm or too wet in autumn and winter. Move it somewhere cooler and drier.
• Wrinkled canes: Too dry or rotten roots. Check the roots; during the rest, slight wrinkling is normal.
• Spider mite, mealybug and scale: Fine webbing, white cottony tufts or small brown shells. Wipe the plant with a cloth and a little alcohol or soft soap and repeat weekly.

Through the year

• January: Rest: cool (10–15 °C), little water. Flower buds appear.
• February: In flower. Little water, do not move.
• March: In flower. A little more water as the buds swell.
• April: In flower, then finished. Repot if needed. Resume water and feeding.
• May: Repot if needed. Water freely, feed weekly. Put outdoors from late May.
• June: Growing season: outdoors in partial shade, generous water and feed.
• July: Growing season: water and feed. Shade from fierce midday sun.
• August: Growing season: last feed. The new canes ripen.
• September: Stop feeding and water less. Bring indoors before nights drop below 10 °C.
• October: Move to a cool (10–15 °C) and drier spot.
• November: Rest: cool and dry, plenty of light.
• December: Rest: cool and dry, plenty of light.

Did you know?

• The genus name comes from Greek: dendron (tree) and bios (life), because these plants live on trees.
• Dendrobium is one of the largest orchid genera, with hundreds of species.
• Dendrobium nobile is a parent of many hybrids sold in garden centres as ‘nobile type’.