Phalaenopsis Gold Tris 'Desk Pot' keiki in full bloom

Phalaenopsis Gold Tris 'Desk Pot' 

About 3 months after I first noticed the start of a spike, my little Phal Gold Tris Keiki is in full bloom!  The flower spike is bigger than the orchid itself, with 4 full-sized yellow flowers. Of course, the mother plant produces larger numbers of flowers and multiple spikes, but this is still one precocious bloomer!

Closeup of Phalaenopsis Gold Tris 'Desk Pot'

The color is less saturated than usual, most likely due to the very warm weather of the last month.

Flower spike on a tiny keiki

A 1 year old phalaenopsis keiki

I first wrote about this Phalaenopsis Gold Tris keiki just over a year ago.  Keikis are orchid clones that sometimes grow on a mature orchid plant. Late last summer, when its roots had grown over 3 inches, I cut the keiki from its mother orchid, and planted it in the pot shown above.  The little orchid has more than tripled its roots system since then, but hasn't done much growth with its two leaves.

flower spike on a 1-year old keiki

Today, I noticed a green nub growing to the side of the orchid's base.  Much to my surprise, this wasn't some errant root, but actually a tiny new flower spike!  Although I have heard before that keikis sometimes flower within a year of growth, I never expected it from an orchid this small.  Its flowers would be almost as big as the entire orchid plant!

I'll be watching closely to see how this flower spike develops.

What causes a phalaenopsis to grow a keiki?

Phalaenopsis keikis: Noid Phal keiki on left, Phal Gold Tris keiki on right

Happy 2017 everyone! December/January tend to be a colorful time for orchids in my terrarium.  The shorter, colder days of September provide the perfect signal to induce my Phals to spike.  The flower spikes generally develop over the next two months, and come into full bloom around the turn of the new year.

However, this year, some of my spikes started growing aerial plantlets (or keikis) in addition to flower buds.  The keiki on my noid phal looks like a leaf growing off the side of a new flower spike.  Meanwhile, Phal Gold Tris produced a tiny plantlet at the tip of an old spike that bloomed over the Summer.

I have written about growing and separating phalaenopsis keikis in the past, but this time I was curious about what caused my orchids to produce keikis in the first place.

What causes a phalaenopsis to grow a keiki?

The internet has many claims about what causes an orchid to make a keiki, but offers little evidence in support.  And even in the research literature, I struggled to find a definitive answer.

So what do we know about Phalaenopsis keikis?  I found a common claim that if a phalaenopsis with a new spike (<4 inches) is exposed to temperatures above 28C (82F), then the spike will develop keikis instead of flower buds.  

See examples:

if a plant with a young inflorescence (less than 4 inches or 10 cm) is subsequently grown at 82 F (28 C) or higher, a spike can form a vegetative air plantlet known as a “keiki” instead of flower buds, buds may abort or both. (Phals article from AOS.org).  

"if a plant with an inflorescence <10cm is subsequently grown at 28C or higher for extended periods, a spike can form a vegetative air plantlet referred to as a "keiki" instead of flower buds, buds may abort, or the stem may elongate indefinitely without open flowers [Sakanishi et. al 1980]"  (Roberto G. Lopez and Erik S. Runkle, 2005)

However, when I tried to find the original source for this claim, its evidence is weak.  Sakanishi et al is a 1980 paper describing the Effect of Temperature on Growth and Flowering of Phalaenopsis amabilis. However, this paper never actually reported any keikis!

In fact, the authors found that high temperatures caused flower spikes to abort growth and flowering.

With the object of determining the effect of high temperature treatment started from the different stages of stalk elongation, 12 plants in the greenhouse were shifted to minimum 28C at each time when flower stalks reached a length of 5, 10, 21-30, and 41-50 cm.  The high temperature from the 5cm stage caused the abortion of florets or the stunted growth of the flower stalks. After the stalks elongated more than 10cm, every stalk normally developed into flower even at the high temperature.

 In the closing remarks, the paper references an even older study on Phalaenopsis schilleriana, which makes the claim about keikis being triggered by temperature.

At ...(maximum temperature 29-34C; minimum temperature 24-25C), [Phalaenopsis schilleriana]  adult plants develop a stalk, which remains vegetative and develops an adventive plant.           (De Vries JT, 1953)

This paper "On the flowering of Phalaenopsis schilleriana" dates back to 1953, and is not available online.  Thus we only have a second-hand description of its findings from the Sakanishi paper.  However, it appears to be the sole parent of all the claims regarding temperature control inducing keiki formation.

What does keiki paste do?

A number of companies sell a product called "keiki paste" which when applied to a dormant node on a flower spike can help induce growth of a keiki.  The active ingredient of keiki paste is a chemical called BAP, or benzyl adenine.  BAP is a synthetic plant growth hormone.  It stimulates activity from flower spikes, and can produce either flowers or keikis depending on environmental conditions.

Which still does not answer our original question about what conditions make a Phalaenopsis develop a keiki instead of flowers.

The final verdict?

I don't think we actually really know the answer to this question. 

Orchid research is not particularly interested in this question. Commercial growers optimize conditions to produce flowers, not keikis.  And keikis are an inefficient way to reproduce orchids on a commercial scale, leaving little incentive to study keikis when there are important questions to be worked out in meristem cloning and in vitro seed germination techniques. 

If anyone reading this has come across a different claim about phalaenopsis keikis, I'd be happy to look into whether it has a scientific backing.  However, in the meantime, I don't think we know what cocktail of light/temperature/water/nutrients is the Goldilocks recipe to trigger keiki growth.

Second phal keiki removed from mother plant

Phalaenopsis with keiki ready to be removed

     About a month ago, I removed the largest of the keikis from my noid phal. Today I removed and potted the second keiki, which I'll be logging as "Phal noid 'keiki 2'. 

Phalaenopsis noid 'keiki 2'

     After 13 months of growth, the keiki is ready to be potted on its own.  The main trigger for removing it was that the spike started drying up above the keiki, and would soon no longer provide it nutrients.

Phalaenopsis keiki ready for potting

     With two roots that are 3.5" long, and two leaves, this keiki is ready to support itself.  Just like last time, I soaked the roots in water+superthrive, and curled them into a 3" slotted plastic pot with phal bark media. 

Newly potted phalaenopsis keiki

     The loosely packed coarse media dries very quickly in a small pot like this one, so I will be watering it every 1-2 days.  My thought is that this should allow me to both water frequently, but still let the roots acclimate to being buried in media without having them stay moist for extended periods of time.  I don't know if this is necessary, but the first keiki is doing fine one month after potting, so I see no harm in using potting conditions that don't maintain much moisture.

     The phalaenopsis mother plant now has only one keiki left.  This one is much smaller than the others, and its roots (1-2") are still much too short to support it on its own.  The mother plant is looking quite drained now; it shed another of its long leaves, and the remaining ones have taken on a withered and leathery appearance.  There is new root growth, and the old roots seem to be healthy, but the newest leaves have been coming in short and stunted.  Hopefully once all the keikis are removed, then this phal will be able to recover.

New growths on phalaenopsis spikes

     On the other hand, the spikes have recently activated two new growths.  It's too soon to tell whether these are spike branches, or the starts of even more keikis.  The keikis looked very similar to this when they first appeared, before the leaves unfurled.  I'm really hoping that these are spike branches though, that will lead to flowers.  In part because I don't know what I'd do with even more white noid phals.  But also, because another year of growing keikis might be terminally draining on the mother phal (even more so than blooming).  

     Time will tell.