Cyp Acaule: smaller bloom this year?
 

Does anyone have any ideas as to why my cypripedium acaule semi alba would have a smaller flower this year? Last year it was fairly large, when I reported it this year the corm seemed to be the same size as before but the flower that is coming up is appearing to be almost half the size. It hasn't opened up fully but I am left concerned.
Advise?
chris

Not many people grow Cypripediums. I don't own Cypripedium acaule, but I do own some terrestrial orchids.

Okay...

1. Do you test the pH of your soil?
2. When you repotted what kind of soil did you use?
3. Does the soil contain mycorrhizal fungus?
4. Did you keep some of the older soil in with the new one?
5. Was there a heat wave anytime during the course of the year?
6. Do you fertilize and what kind do you use (organic or inorganic)?
7. Is it receiving enough light?
8. How many plants are in the pot?
9. Do you water enough?

There is a book on how to grow hardy orchids. That may be more helpful.

I used some of last years mix...
I made up the same mix this year which is some Partially composted pink bark, long fiber Sphagnum moss, a little peat, and some perilite.
I do add mycorrhizal fungi in the mix... it is powder form.
I don't fertilize because I have read that this species doesn't respond well to fertilizer. maybe that's it? Maybe it does like fertilizer but purely organic.
I don't test the PH, I also read that watering every other time with a light amount of apple cider vinegar does the trick...Only one corm in the pot, and it gets lots of light and the proper amount of water.
One concern you brought to my attention is that during our Washington winter, we did have a little bit of an early spring heat wave, but otherwise the most of the winter was colder than usual.
Thanks for the ideas... maybe it was the heat or lack of fertilizer?
Chris

Thanks for the book advise. I didn't register on the site you provided to see what book you are suggesting however, I have two books based on the subject... Maybe there are more... I will look into it.