Stanhopea Spring 2013

Spring is well under way and Stanhopea are showing signs of growth and preparations for inflorescences. While some Stanhopea have just begun new growth, others have just completed winter growth, and still others have not grown since last fall.  It has been interesting to note how varied the timing and duration of growth Stanhopea exhibit as my collection has increased.  Growth in Stanhopea can be so variable between species and even sometimes between different forms of the same species.  Some of the easiest species of Stanhopea that I find to grow (S. oculata, S. tigrina, and S. wardii) grow intermittently throughout the year, taking short breaks between growth cycles.  Other Stanhopea such as (S. anfracta, S. gibbosa, and S. panamensis) begin a growth cycle in early to mid-spring, and then again in summer before flowering.  Other Stanhopea (e.g., S. insignis, S. lietzei, and often S. shuttleworthii) don’t begin growth until summer and then only produce one cycle of growth. 



Stanhopea tigrina "Glory of Mexico" with new maturing growth from late winter (left).  Stanhopea posadae with new growth started in early spring (center). Stanhopa anfracta with new growth started in spring (right).



These differences between the growth cycles of different species may be due to cultural conditions, or the maturity of the Stanhopea plant.  The species that grow intermittently through the year may be because they are the best adapted to the growing conditions that I have, and thus grow almost continuously.  In addition, these Stanhopea that grow well may be doing so because they are some of the largest specimens that I have and happily grow throughout the year.  This latter option may not be very consistent because two of my large Stanhopea (S. ruckeri and S. shuttleworthii) only produce one growth cycle per year.  It will be interesting to see if these observations of growth cycles remain consistent or vary over time and as the plants age.  It would be appreciated if those of you who have different growing conditions than mine (e.g., greenhouse conditions or a tropical climate) could post some of your observations.  Knowing when Stanhopea start new growth cycles and when they bloom allows us to determine the best time to transplant them (either spring or fall) depending on the species.  I usually attempt to re-basket Stanhopea just before a new growth cycle begins while the plant is dormant, and either before or just after flowering for the year.

Stanhopea frymirei (left), Stanhopea impressa (center), and Stanhopea nigripes (right) with new growth starting in mid-spring.