Spiking Phalaenopsis

Ask ten successful growers how they care for their orchids and you will get ten different answers. One technique that everyone can agree on, however, is how to bloom their phalaenopsis.

Surprisingly, the average consumer is not generally aware of this ‘secret.’ Plant care tags describe the culture necessary to keep the plant alive but often fail to mention what is required for re-blooming. Maybe that’s because marketers don’t want their clients to know this critical information – preferring, instead, to sell them more plants next year.

For some houseplants, the trick to blooming is in the fertilizer. Traditional wisdom has been to increase the amount of phosphorous in the feeding regime. Plant food labels list the three most important nutrients, expressed as ratios, of nitrogen, phosphorus, and potassium or N-P-K (For example, 20-20-20).The higher the middle number, the more phosphorus is in the formulation.

For other houseplants, a change in light levels will trigger a blooming. African violets respond to increased sun and produce additional blossoms with extended daylight hours. Poinsettias and Christmas cactus require daily periods of total darkness over several months in order to get flowers. Sometimes, the changing trajectory of the sun as the seasons change is all that is needed.

Orchid care generally mimics that which epiphytes receive in the jungle. The most common habitat for the majority of species within the Phalaenopsis genus is one that is steadily warm and moist throughout the year. The plants are found along streams and rivers in the lowland evergreen forests throughout Asia and the larger islands of the Pacific Ocean. Seasonal climate changes, particularly in temperature, trigger their annual flowering.

Hobbyists can duplicate the ‘flower spiking’ conditions by providing cool night temperatures in autumn. Mother Nature does this naturally as outdoor thermometers show 50 degrees in late September and early October.  There is no set formula for optimal spiking but several weeks of night temperatures in the 50’s will almost guarantee the emergence of a new flower spike within a month.

There are professional growers who will additionally alter both the fertilizer and the light level while providing cooler temperatures but these advanced techniques are not necessary for the hobbyist. We have found that keeping it simple is the best course of action. After cooling the plants in Sept/Oct, expect flowers by January.

Tuesday, September 1, 2015 - 03:15