The Orchid Clock

We continue to receive requests for information about the "orchid clock" written about by T.J. Hartung in the January, 2011 issue ofORCHIDSmagazine. This simple device makes it easy to keep track of your orchids annual growth cycles. With the first day of Autumn occurring this week, we thought it timely to reprint his explanation of how to use the device. Click the clock at left to download a printable template.

Orchids have a cycle of life. The key to understanding the annual life cycle of a plant, and knowing how to respond to it, can be depicted visually as a clock.

Orchid growers know their plants will produce flowers at a certain time of year, and will grow new leaves and rhizomes at another. By charting these on a clock face, we can better respond to the needs of the plant in terms of fertilization, watering, etc.

Every species of orchid is different. Some orchids bloom in May and June, others flower in time for certain holidays. Some have blossoms that last for only a few days, while others last for months. Also, exact timing can depend on a number of factors, including the region of the world in which the plant lives.

This orchid clock should be duplicated for each species that you have. Here’s how to chart a time cycle chart for every species in your collection. Begin by placing an arrow, pointing clockwise, at the time of year when a new inflorescence appears, and another arrow, pointing counterclockwise when the blooms fade. Place both arrows in the ring marked “Inflorescence Growth.” Repeat this for the leaf growth ring and the root growth ring.

By seeing the times of the year when each of the significant growth patterns occur, we can now plan to fertilize our plants in a timely manner. To better visualize the fertilization patterns, I use three different colors of highlighter marker pens: green for growth, yellow for blooms and pink for roots.

Start the highlighted area of the ring two–four weeks before the beginning and continue it to almost the end of the particular growth pattern. (There may be some overlap in ring colors.)

Fertilizers are identified with three numbers, which I refer to as “Shoots,” “Fruits” an element needed for plant growth. The second number is phosphate (P2O5), a chemical shown to increase flowering (and fruiting). The third is potash (K2O), a chemical needed for root growth, overall plant health and stamina.

During the “green” time of year, I recommend a fertilizer that is 20-10-10. During the “yellow” time of year, consider a 10-20-10 fertilizer. The “pink” season calls for a 20-20-20 fertilizer. Any similar fertilizer formulas should be sufficient. The last ring — entitled “Rest Period” — is when your plant needs to rest and muster its strength for the next year’s growth. During Rest Period, fertilize and water sparingly.

By looking at your orchid clock (and a calendar) you can now easily see what kind of fertilizer each species of orchid in your collection needs. The colors of the highlighter pens were chosen because they approximate the color of the fertilizer I use.

T.J. Hartung is president of the Vallarta Orchid Society in Puerto Vallarta, Mexico. He is also on the board of directors of the Vallarta Botanical Gardens. Puerto Vallarta, Mexico (e-mail