Cymbidium Alexanderi gx

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boat orchid Alexanderi gx

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A large-sized, evergreen orchid with linear, dark green leaves up to 90cm long and 2cm wide. Ovoid pseudobulbs covered with basal leaf sheaths carry six to ten leaves. The orchid flowers in early spring on upright or arching stems up to 100cm tall, carrying up to 30 flowers. The flowers are white, pale pink or cream, depending on cultivar, each measuring 7-9cm across. Perhaps the most famous cultivar 'Westonbirt' with large pure white flowers and with pink markings on the lip was originally registered in 1911. It is the first orchid hybrid which was identified a tetraploid - carrying four (instead of two) sets of chromosomes, which set a start to a very successfull history of breeding.

Position

Partial shade

Max Height

0.5-1 metres

Max Spread

0.5-1 metres

Size

Time to Maturity
2–5 years
Max Spread
0.5-1 metres
Max Height
0.5-1 metres

Growing Conditions

Moisture
Well–drained
pH
Neutral

Position

Partial shade
Aspect
East–facing or West–facing
Exposure
Sheltered
Hardiness

Hardiness Ratings

All ratings refer to the UK growing conditions unless otherwise stated. Minimum temperature ranges (in degrees C) are shown in brackets

  • H1A: under glass all year (>15C)
  • H1B: can be grown outside in the summer (10 - 15)
  • H1C: can be grown outside in the summer (5 - 10)
  • H2: tolerant of low temperatures, but not surviving being frozen (1 to 5)
  • H3: hardy in coastal and relatively mild parts of the UK (-5 to 1)
  • H4: hardy through most of the UK (-10 to -5)
  • H5: hardy in most places throughout the UK even in severe winters (-15 to -10)
  • H6: hardy in all of UK and northern Europe (-20 to -15)
  • H7: hardy in the severest European continental climates (< -20)
H1C

Colour & Scent

Season Stem Flower Foliage Fruit
Spring
Summer
Autumn
Winter

Botanical Details

Family
Orchidaceae
Native to GB/Ireland
No
Foliage
Evergreen
Habit
Clump forming
Potentially harmful
Skin allergen. Wear gloves and other protective equipment when handling
Genus
Cymbidium are epiphytic, lithophytic or terrestrial orchids with prominent spherical to ovoid pseudobulbs, long linear leaves and fleshy white roots. Several long lasting showy flowers with a distinctive 3-lobed lip are borne on erect or arching flower spikes from the bases of the pseudobulbs
Name Status
Accepted

How to Grow

Cultivation

Grow in an open, free-draining orchid compost with addition of perlite, sphagnum moss or coir. Requires day temperatures around 16°C and 10°C at night. Provide good light levels, but avoid direct sunlight. Water plants thoroughly when compost is almost dry, allow to drain and use orchid fertiliser regularly during growing season. Reduce watering in winter. Place outside in dappled shade during the summer months to aid flower initiation. See cymbidium cultivation for more detailed information.

Propagation

Propagation by seed is only possible in a controlled laboratory environment. Mature plants may be divided in early or mid spring, when the plant overgrows its container. Each division should have at least 3 older pseudobulbs with a sufficient amount of stored energy and water, to support new growth and reduce stress after repotting.

Suggested planting locations and garden types

  • Houseplants
  • Patio and container plants
  • Conservatory and greenhouse
  • Cut flowers

Pruning

No pruning required. Cut down flowered stems to base.

Pests

May be susceptible to aphids, glasshouse red spider mite, scale insects and mealybugs

Diseases

Generally disease-free. Sterilising cutting tools may prevent virus diseases, such as Cymbidium Mosaic Virus (CMV).