Warm loving cymbidiums

Most cymbidiums that are in cultivation require a distinct 20-25 degree difference in the day and night temperature, with the night temperature below 57 at night during the bloom cycle. Additional parameters are below the mid 90s during the day, and above 28 degrees at all times. Many of us live where these parameters just don’t exist. The central to southern coast of California is ideal with the marine layer at night, and warm days.

So for those who live in southern states, Hawaii, or have heated greenhouses, or want orchids as house plants in the very northern climes, warm loving cymbidiums are perfect.

Problem is there just isn’t a good definition of warm tolerance, nor can we point to exact breeding lines. Many in the cymbidium world have tried to define warm tolerance, but it is difficult. For some, it is heat tolerance, i.e. able to withstand 95 degree Bangkok weather and still flower. For others, it means a narrow difference between day and night temperatures all year long.

Many warm loving cymbidiums will bloom regardless of the difference in temperature between day and night and if the low temperatures are above 60 degrees. These are the ones we are working with. In most cases they will bloom anywhere and in some cases several times a year.

Some come from well known warm loving parents such as madidum, canaliculatum, aloifolium, dayanum, finlaysoniaum, and ensifolium. Most often the offspring will be warm loving as well. However it may depend on what these are crossed with.

Kobsukh Katraena of Pakkret Orchids in Thailand suggests the following heat factor ranking:

Heat Factor

Cym ensifolium subsp haematodes 10.0
Cym canaliculatum 10.0
Cym aloifolium 10.0
Cym finlaysonianum 9.5
Cym ensifolium subsp ensifolium 8.5
Cym dayanum 8.5
Cym bicolor 8.5
Cym atropurpureum 8.5
Cym madidum 8.0
Cym munronianum 8.0
Cym chloranthum 7.0
Cym sinense 5.5

Kobsukh discovered that heat tolerant madidum crossed with cooler loving hybrids will produce offspring that are not as heat tolerant. For Kobsukh in Thailand, Pat Ann, Sunshine Falls, and Parish Madness will lose their buds. In Hawaii these same crosses are all very stable and show no loss of flowers in the warm regions. Even Super Baby ‘Autumn King’ will drop buds in Thailand, while it is very prolific in Hawaii at most elevations.

Some species will only exhibit warm tolerance in combination with certain other hybrids. And contrary to what one might think, it is often combinations with hybrids that are cool loving, particularly if they are tolerant of high and low extremes. Parishii (sanderae), while not on this list, often produces warm tolerance in combination with other hybrids, as does floribundum. Pearl Sachiko is Olymilum (floribundum x Olympus) x erythrostylum, yet it blooms well here on the Big Island in warm regions, possibly from the floribundum influence. The same can be found with Sarah Jean 'Ice Cascades' (floribundum x Sleeping Beauty) which blooms easily in Hawaii.

The possibility exists that some of these species have different races that are warm tolerant within the species. Parishii (sanderae), insigne, floribundum and devonianum may in fact have cool weather and warm weather races within the species which may partially account for the variability with different crosses warm tolerance.

Another possibility in creating tolerance in hybrids may be in having ancestors that are ensifolium AND floribundum together for example.
Other combinations may create larger flowers and longer life. Toward this end the breeding work continues.

We invite you to send us what you have found that works for you in your region, and the conditions that you have. With your input, we will continue to seek varieties that will work for the largest number of people living in warm conditions. With global warming, this in fact may be an increasing segment of the population.


Bob Harris
Jennifer Snyder