Lots of new leaves and roots, but no spikes! Why?!

[gngrhill]

Little has been said about the temperature drop. All of mine are out on the porch in fall so they get that drop in temp over night. As soon as they start a spike I move them in where I can enjoy the blooms.

[PaphLover]

Originally Posted by PaphMadMan

They look basically healthy so the most likely cause is not quite enough light. With some Phals a little bit of a chill in the fall may trigger flowering. Have you reported them since you got them?

PaphLover: Once I did that and opened the window at night in the summer/ fall, the change in night temps has consistently initiated spikes for me. Since I sleep with my bedroom window open at night all year, I just bring the ones I want to spike in there and put them on my bedroom windowsill for a few weeks and that seems to do the trick for me. Once a spike is initiated, I put it back into the warmer living room (no open window at night) and bring the other plants into my bedroom to get them spiking. This is what's been working for me.

Hmmm, we both mentioned a cooler temp causing spiking. These threads can get long. Maybe our suggestions were missed when you read through.

[camille1585]

I live in the Netherlands, and my Phals live on a south facing windowsill year round. It's far north enough for the light to not burn them, once they've been acclimated.

Many of these same Phals bloomed fine at my old apartment (north-east windows) though the flower count was much lower than it is at my current place. I never give any of them a nighttime cooling period, as it's a myth that phals need cool night temps in order to bloom. What they respond to is a overall cooling down, which naturally happens when summer ends, even indoors. (At my place the temperature indoors drops from 25-26C to 19-20C)

As to the fertilizer you use, those sticks are not adapted for orchid needs and the bark based mediums they grow in. It's better if you get an orchid specific fertilizer, or use a standard fertilizer at a very weak strength. Phals, and many orchids in general, appreciate getting very small doses of fertilizer on a regular basis (in my case every 2-3 waterings).

In any case, you won't see any effects of the changes you make until autumn, which is when the majority of Phals will start spikes.

[Beatrice]

Thank you everyone. I tried putting them on the windowsill these last two days and during the midday hours the leaves get very warm from the sunlight, I'm not sure that's ideal. Are there any specific signs of damage that I can detect early in case it's too much light?

It may be the length of exposure - there are some tall buildings outside so there isn't that much light coming through except when the sun is highest.

I do have a temperature drop every autumn because it's an old building with draughty windows, and I generally keep the window open a crack at night.

I will experiment and see what happens. Thank you again, venerable orchid sages!

[Roberta]

If the leaves are very warm to the touch, definitely you should move the plants away from the window or use a sheer curtain to diffuse the light - unfortunately, often the first symptom of too much heat is a burn spot on the leaf that is permanent. You can't really compensate for inadequate duration of light by increasing intensity very much. Much better to add supplemental light from an LED or fluorescent lamp to "stretch the day"

[Beatrice]

OK, thanks Roberta, I will try that!