Phalaenopses - is cutting of spikes advantageous/neutral/detrimental to the plant?

[Delila]

Is anyone aware of any research that shows definitively whether the cutting of spent or almost spent flower spikes on Phalaenopses actually advantages the plants in any way? It's often spoken about as 'redirecting energy into the plant', but does it really?

In particular I'm wondering whether cutting a near-spent spike may encourage root growth in a plant that desperately needs new roots, by 'informing' it that flowering is definitely over so it can focus on other things.

On the other hand, in nature a spike dies back slowly, with the main plant re-absorbing its moisture and nutrients. From this point of view, the cutting of still fresh spikes would seem quite detrimental.

Thanks

[ksriramkumar]

In my view, if want the plant to root, I would cut the spike if there are still internodes that haven't bloomed. if there is a spike, as a survival call, it could initiate blooms from the internodes that have bloomed and cutting the spike would keep the distractions away and allow it to focus on rooting

[Carolla]

I find failing plants have spikes that die back pretty quickly. I don't know if the plant absorbs any of the nutrient in the spike. I leave nice green spikes on mature healthy plants, though I've been told that a plant that reblooms an old spike while putting up a new one doesn't flower as well on the new spike as it would if the old were cut off. My personal take is to let them do their thing and enjoy them. Oh, I did have a struggling plant put out a keiki on a spent spike and both the keiki and the mother plant are doing great a few years later (though I've never gotten it to bloom, the plant is now the picture of health!).

What I would do is to concentrate on getting those roots to grow, be sure they are in the right media for your conditions, don't repot them more than once (if you think it best for their health to repot at all) and treat them with a kelp based product to encourage root growth. Phals also like warmth at the roots and avoid stress on the plant.

Good luck with your Phal!

[raybark]

Generally, I feel that simply leaving bare inflorescences alone is the best option. If the plant has the reserves to reblooom, it will; if it does not, it won't. The plant may form a keiki, as Carol mentioned, or may "resorb" the nutrients invested in the spike, it will turn pale and die.

Removing it entirely takes away those opportunities, but I don't feel it's a significant setback, nor a stimulus to grow roots.

The worst thing you can do is to cut the spike near its base node in order to stimulate reblooming. That saps the energy stores within the plant, weakening it overall, and all you get a fewer, smaller flowers.

[chemist]

I don't have any scientific proof but my observations.
Firstable to clear the points Delilah talks about a plant that desperately needs new roots.

All the above that Ray said I think its true about healthy plants but if plant has the spike and no or little roots to support it its in plant's best interest to cut spike off even if flowers are still nice.

Think about it that all water/supplements roots can get have to be shared between leaves and the spike. So by cutting spike you let those recourses to go to leaves so they can photosynthesis all necessary stuff for plant living. The more stuff is in leaves the more those leaves can support the whole plant until it will grow new roots.

So my observation is that (on healthy plants) existing roots are still growing while plants are in spike but don't produce new root growth. As soon as most of flowers or last flowers are gone you can see new leaf forming and new roots showing up.
The people who using keiki paste talk about research made about hormones produced by the plant during flowering stage and vegie (leave growing) stage. So yes the plant sends info if its time to leaf/root growth.

By cutting spike you will decrease flowering hormones and plant will think its time for veggie stage.

Also Delilah, you don't give us enough info, in what exactly condition are existing roots?

if there is only one healthy root for big leave mass and the spike than spike will suck all nutrient from leaves to support flowers, but at the end you might loose whole plant. So you have to make decision what you want to save plant or flowers.
You can cut spike and keep it an a vase for weeks and save whole plant. I was there, done that, now phal puts new roots

[PaphMadMan]

In Phals, a living spike is green tissue capable of physiological processes, including photosynthesis. Auxins the plant produces to trigger rooting are actually produced in meristems, and a spike has several. Unless it is a particularly small or weak plant it takes comparatively very few resources to support it, and removing it ipotentially reduces overall photosynthesis and auxin production. If you feel like that is something you must do to your plant, feel free.