Why won't my orchids bloom?

Kirk Hoo, Contributor

A widely asked question is: "Why won't my orchids bloom?" Although there isn't a simple solution to this question, there are a few guidelines which will help you understand how to improve your orchids' flowering.

LIGHT

All plants require a certain amount of light for proper growth and to flower, and orchids are no exception. You first need to determine the light requirements of the different types of orchids before you decide where to grow your plants.

VANDACEOUS

Semi-terete vandas require full sun for the most of the day to flower well. Mokaras can be acclimated to growing in full sun along with your semi-terete vandas. Strap leaved vandas and ascocendas need bright light but should not be exposed to direct sunlight, especially at midday.

CATTLEYAS & DENDROBIUMS

These require semi-shade conditions and are grown best in an area which gets bright light but no direct sunlight (about 50 per cent sunlight).

PHALAENOPSIS, ONCIDIUMS & PAPHIOPEDILUMS

These plants grow best in shady conditions and at no time should they be exposed to direct sunlight.

FERTILIsER

Another factor which is critical for proper orchid culture and flowering is feeding your plants. A weekly solution of a balanced fertiliser will do wonders. A balanced fertiliser is one where the ratio of nutrients N(Nitrogen):P (Phosphorous): K (Potassium) are equal. So when reading a fertiliser label which states 20:20:20 it means equal parts N:P:K. Fertilisers such as Tropi-Gro Orchid Plus have been specially formulated for orchids growing in the tropics.

INSECTS

If your plants fail to bloom despite receiving adequate light and proper nutrients, pests are probably the cause. Thrips are the usual suspects that attack the young, tender tissues of the plants. Thrip damage is most evident on flowers and appears as dried areas on the petals and sepals, especially where they overlap. In severe infestations they attack emerging flower inflorescences and young buds, many times causing the inflorescences and buds to dry up before they reach maturity. Thrips tend to be more prevalent in hot, dry conditions so one has to be on the lookout for these pesky critters. Once you have determined that you have a thrips problem, a suitable insecticide formulated for sucking insects, such as Danitol 10EC or Dimethoate, should be applied at the recommended doses.

So if your orchids are reluctant bloomers, ensure that they are getting sufficient light and fertiliser and that there are no pests lurking in your garden.

Orchid Society meeting

The Jamaica Orchid Society meets on the first Saturday of each month at 4 p.m. at the JTURDC Building, 1A Hope Boulevard, Kingston 6. The annual orchid show will be held at the Jamaica Horticultural Society Showgrounds, Gibson Drive, Hope Pastures, Kingston 6.