19 January 2018

Caring for your orchids

Horticulturist Elisa Biondi shares her top tips on how to care for your windowsill orchids.

By Elisa Biondi

Orchids at Kew

Orchids are perfect for bringing an exotic splash of colour into your home.

Here I will reveal how you can grow them successfully, and where you can see vibrant displays to inspire you. 

Choose your plant 

You can buy windowsill orchids at garden centres, supermarkets and specialist orchid nurseries.

Choose a plant with some open flowers so you can see what you will be getting. Moth orchids are one of the easiest to grow and so are a great choice for your first orchid.

Essential care 

Orchids have a reputation for being difficult to grow, but actually make robust and rewarding houseplants. 

Orchid festival
Orchid festival © RBG Kew

Feeding 

  • Only feed your orchid when it is actively growing. This is when you see new flower stems or roots appearing. 
  • Use a normal houseplant fertiliser (diluted to half strength) with every other watering. 
Orchids at Kew
Orchids at Kew © RBG Kew

Watering

  • Water from the top when the pot feels dry and light in weight.
  • Allow to dry out between waterings.
  • Orchids prefer rainwater to mains water in hard water areas.
  • Place your orchid on a tray of wet pebbles to increase humidity.

Repotting

  • Repot orchids every two years.
  • After flowering, remove old flower spikes and tip the plant out of its pot.
  • Gently remove old compost from roots and remove any dead roots.
  • Repot in the smallest pot possible - preferably the same pot it came out of. Cymbidiums flower best if pot-bound.
  • Fill with a moistened, bark-based orchid compost.

Pick its home wisely 

Choosing the right place for your orchid is the key to success, and depends on which orchid you are growing. 

Orchid festival 2020
Orchid festival 2020 Zoe Stewart © RBG Kew

Moth orchids (Phalaenopsis) and slipper orchids (Paphiopedilum) 

  • A central-heated room with a minimum temperature of 15°C is ideal. 

  • Choose a well-lit place, away from direct sunlight and heat sources.
Orchids at Kew Gardens
Orchids at Kew Gardens ©RBG Kew

Cymbidium and Dendrobium hybrids 

  • During winter (October to May) a cool room with good light and a minimum temperature of 11°C is ideal. 
  • In summer they will thrive outside. Exposure to changes in day length and a slow drop in temperature improves flowering. 

Oncidium species 

  • Place in a well-lit position. 
  • A minimum temperature of 13°C is essential to encourage flowering. 
Orchid festival
Orchid festival, Ines Stuart-Davidson © RBG Kew

Miltonia, Cambria, Odontoglossum, Oerstedella, Masdevallia and Epidendrum hybrids 

  • These orchids need a cool, well-lit position, out of direct sunlight. 

  • A minimum temperature of 11°C is required.

Your orchid will flower again

Here are some top tips to promote reflowering: 

As each flower wilts and turns brown, remove it from the flower spike. Then, when all the flowers are over, cut the whole spike off cleanly about 3cm from the base. The orchid will then concentrate on leaf growth. It should flower again the following year. 

If you have a moth orchid (Phalaenopsis), this will flower again more quickly if you cut the spike just above the third node from the base.

A colourful illustration featuring Indonesia orchids, orangutans, volcanos and other flora.

Orchids 2020

The orchid festival is back, celebrating the magnificent biodiversity of Indonesia, the land of 17,000 islands.

Read & watch