November Notes from Sunset Valley Orchids

[Roberta]

Here are some notes on fall care for Catasetinae, from Sunset Valley Orchids:
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"November 2023 Sunset Valley Orchids

Catasetinae Growing Tips




What a great year! Feedback from Catasetinae growers across the country has confirmed that this was a spectacular growing and flowering season.


Now that winter is knocking at our door steps, most of your Catasetums should have matured growths and be mostly done flowering, Cycnoches will be finishing their blooming, Mormodes should be flowering soon, and Clowesia should be starting before too much longer.


Those of you in Florida and southern states may already have dormant plants. Those in other areas like here in California should be seeing good signals indicating the start of dormancy, with the lower leaves starting to turn yellow and brown before they drop off.
2023_ctsm_leaves image

These four plants (see photo below) demonstrate the first stages of dormancy, from left to right: 1) no signs, 2) slight leaf tip yellowing, 3) obvious yellowing and beginning of leaf tip die back, 4) several yellow leaves and tip die back clearly evident.



Leaf yellowing and drop signal the beginning of dormancy. This is when you stop fertilizing and cut back on watering frequency increasing the length of the dry interval in between each watering, simulating the end of the wet season as in nature. This important change in irrigation will cause the pseudobulbs to harden off in preparation for the upcoming months of dormancy. When most leaves are yellow/brown and have fallen off, cease watering altogether. This marks the start of the dormant period.


Some Catasetums, Cycnoches, Clowesia and most Mormodes begin their flowering season at the end of the growing season, coinciding with the changing environmental conditions, and onset of leaf yellowing and in dormancy. In these cases, it is natural for the flower inflorescences and blooms to begin while you are reducing irrigation frequency. Some plants don’t even start to develop inflorescence until well after all water is stopped and the plant is totally leafless! Generally, it is not necessary but if your plants pseudobulbs shows signs of shriveling during late season flowering usually one or two extra waterings will quickly plump it back up.


Interestingly, not all plants enter dormancy on the same schedule, and it is not uncommon to have plants in several stages of dormancy at the same time. As plants progress toward their dormant period, I organize my Catasetinae into groups at similar stages of leaf loss. Grouping plants this way makes watering easier and assures proper transition into dormancy. Also, not all plants lose all of their green leaves when dormant, and it’s not uncommon for some to hold a few leaves well past the point when irrigation has stopped.


We know that dormancy is caused by several factors like the maturity of the pseudobulb and the reduction of root zone moisture. There are 3 other important environmental factors that occur naturally in nature and they play an important role in initiating dormancy: 1) differential between day/night temperatures 2) light intensity 3) day length adjustment.


1) In a Greenhouse the day night temperature differential occurs naturally. When the plants are cultivated in the home or under lights do your best to give at least a 10-15 degree day night differential.


2) It is best to keep the plants at nearly the same light intensity levels as in the growing season, targeting 2000-2500 foot candles. It is easy to download a Foot Candle Reader app for your phone to check what you have.


3) If you’re growing under lights, you do need to adjust the day length throughout the year, as all Catasetinae have evolved to experience seasonal daylength changes."

[Leafmite]

I keep all the emails on orchid culture in my 'orchid' folder so I can re-read them if the need arises.

[My Green Pets]

Sharing where my Catasetinae are at this time:

Mormodia Jumbo World - Only top 3 leaves remain, each with about 1/3 yellow/dieback
Clowesia Rebecca Northen 'Grapefruit Pink' - Leafless, two spikes almost fully extended, buds
Clowesia Rebecca Northen 'Mikabi' - Leafless, one spike just starting
Clowesia Rebecca Northen 'Aurora' - 3 leaves left with top 1/3 of each leaf yellow with dieback
Cycnoches warszewiczii - Fully leafed but yellowing, except for lower smaller leaves which dropped a month ago. Spike nearly fully extended and buds swelling.
Cycnoches cooperi - Bloomed in September, fully leaved but yellowing
Cycnoches Fire Embers - Bloomed in September, second spike nearly ready to bloom, fully leaved, yellowing
Cycnoches Bronze Vixen - Bloomed in October, starting another spike now, fully leaved, yellowing
Cycnoches cooperi (just received from SVO in September) - spike nearly ready to bloom, fully leaved
Cycnoches (Alexis Jesus Pardo × Dark Swan)(just received from SVO in September) - Spike nearly ready to bloom, fully leaved
Clowesia rosea (just received from SVO in September) - 3 upper leaves left, no sign of spikes
Clowesia (Grace Dunn × dodsoniana) - several leaves still but yellowing, no sign of spikes

[Leafmite]

That is quite a nice collection of these cool orchids.

[Greenpots]

Thank you for great note and reminder. Here they are in socal today.

[Leafmite]

Here are my five:
1) Cycnodes Wine Delight 'J.E.M.” FCC/AOS (almost hidden and completely dormant)

2) Cyc. pentadactylon (Cyc. pentadactylon 'H&R' x Cyc. pentadactylon 'Dr. John Doherty' AM/AOS) Green and just about to bloom. It is new from SVO so the spike was all on them.

3) Cyc. warscewiczii (Cyc. warscewiczii 'Green Goddess' x Cyc. warscewiczii 'World Class') No sign of blooming this year. It is also a new one. Still green.

4) Cyc. cooperi (Cyc. cooperi 'Green' HCC/AOS x Cyc. cooperi 'Mem. Pat Worthington' AM/AOS) This one is in bloom. Nice and green, still. Also a new one from SVO.

5) Cycnoches Mass Confusion (chlorochilon 'Giant Swan' x warscewiczii) It is still green. This has just started a spike. It was the membership plant I chose at the Orchid Society meeting. From what I have read, the flowers will look almost exactly like Cyc. warscewicziii so I had better stick those tags deep in the pot when I pot them in lava rock this spring (and maybe write the names on the outside of the pot, too).

[Roberta]

If there is a danger of tags "wandering" - wind, pets, small children... consider putting a duplicate tag in the bottom of the pot when you repot.

[Leafmite]

Exactly. Most of my orchids are species or clones so I can tell what the orchid is when it blooms (I have a list of all my orchids on my computer). This new one adds some mass confusion.