Oncidiums are an excellent choice for beginner orchid growers. They have been nicknamed ‘dancing ladies’ because their large flower petals when fluttering in the breeze, tend to mimic the movement of a flowing skirt. Oncidiums are very showy plants and can put forth an amazing profusion of long sprays of flowers, provided that they receive enough light and the right temperature, The Oncidium genus encompasses several hundred species and can be hybridized with genera such as Brassia and Miltonia resulting in an even greater variety of delightful colours, shapes and sizes.
Due to the wide distribution of this species and the vast number of different habitats in which people might attempt to grow these plants, it’s difficult to generalise the growing conditions required. In South Africa – especially in the warmer climates, we tend to grow hybrids bred from the intermediate to warm growing group of Oncidiums, although hybrids requiring cooler temperatures are grown with ease when the correct cultural requirements are met. Temperature requirements are fairly mandatory, as Oncidiums won’t tolerate cold spells for long. They do cope best where the night temperature does not drop below 15 degrees celcuis and the day temperature does not exceed 30 degrees, unless there is high humidity and air movement is increased proportionally. Normally, green houses provide humidity from 30% to 60% humidity, which is adequate for Oncidiums.
These plants should be watered at least once a week in summer and less often in winter. Plants should be fertilised once a week in summer and fortnightly in winter. Some Oncidiums require a rest period in winter and should not be fertilised, so it’s best to check with your plant supplier at Blackwood’s regarding your plant’s requirements.
Oncidiums can be fertilised with Multifeed P, Seagro, Pokon or Nitrosol at the recommended strength. Repotting should be done when new root growth appears at the base of the pseudobulbs. As Oncidiums have fine roots, potting media should be of a fine grade. Fir bark, tree fern fibre, cultiwool, sphagnum moss or polystyrene beads are all suitable potting mediums. We find it preferable to grow Oncidiums in terracotta pots. Plants enjoy growing in baskets and are also happy growing in trees in warmer climates.