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What I've learned about bringing Phals to spike

17 years ago

I am getting new spikes on Phals like crazy, and wanted to post some notes about it in case it's of help to others who are growing and hoping to flower Phals.

I. Light: I have been "pushing" these phals with light all winter downstairs, and since about March upstairs. Upstairs they were first in a sunny South window, then when the sun shifted, I moved them to a West window, with periods outside.

Outside, (after acclimating) they get full sun from app 8 to 9:30 AM, then 50% shade for an hour til 10:30. Shade til 3:30, then dappled shade from a lattice from 3:30 til the sun goes behind some trees about 7pm.

That's a *lot* of light, and there has been no burn, tho on a hot day, leaves are warming up by 9;30.

All the specialist websites that discuss spiking caution the reader to *increase light* and maybe lower the night temperatures to induce spiking. As I read it, increasing light was necessary.

What I have found:

1. Terrific growth. Big plants growing up to an inch a week, and starting a new leaf every 6-8 weeks. Smaller plants' growth is a little less dramatic. A few extremely vigorous little guys have grown from a 2" pot last summer to a 5 or 6" pot now, with leaf span 12-14".

2. spikes have formed on at least 10 of these phals (all but about two of the mature phals. Two are re-spiking after having the old spike cut off in May. Three are last year 2" babies that have reached spiking size, and three are new 4" plants I got from Carmela this spring.

II. Temperature: A year ago, there was a post here that linked to an article about the role of temperature in preventing spikes on phals. The gist was that *high* temperatures above 85 retarded spiking, and that professional growers use this to retard spikes until they want blooms. "Even a short time at 90 is enough to prevent spiking".

What I've found is that this may be true for standard phals, and maybe even some others. But it is *not* true of all. Most of mine are not standards. Mine have been outside for more than a week in temperatures that have been in the mid-90's every day. My deck themometer (in the shade) has been reading 100, and a thermometer on the plant tables gets over 100 by 10AM and blinks out at 130 if left there.

Despite this heat, spikes that had formed indoors in my west window on three phals have grown a lot in that time; spike nubs on at least two have started to develop; and new spikes have formed on three more. All while outdoors in 95+

A couple do have spike nubs that have not developed, and a couple of fairly large ones have no spike activity yet, tho they had spikes last year. So maybe these have been held back by the heat, but they are the minority.

My tentative conclusion would be increased light is more important in stimulating spikes than heat is at retarding them. P amabilis seems to be light sensitive and needs long nights to initiate blooms, and so standard phals with a large % of amabilis in them may not spike til fall no matter how much light they get. The rest definitely respond to light.

III. Roots. I'm sure experienced growers already know this, but when the top looks good, the roots are good underneath. When the top starts to look poorly, the roots are in trouble. I haven't found any variances from this yet.

If the roots are impaired, my plants usually need an extended period of re-rooting and healthy growth before they venture to spike.

Hope this helps someone who wants flowers.

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