I'm thinking if your terrestrial orchid was planted outdoors, it may have died from the cold, rather than the acid soil, Mother Raphaela. Most of them are a little bit tender for zone 4b, so unless some diligent gardener put a thick mulch over them, the cold probably got them.

Our soil here is slightly on the alkaline side, but where my Spathoglottis grow under my big oak trees it is more acid, so they don't seem to mind that. I know @Ursula grows Bletillas in New Jersey, but her winters are not as cold as yours, and I don't know about the pH of her soil. Perhaps she will chime in here?

Just FYI, the Spathoglottis I have were mostly bought pretty reasonably at the local big box stores. I think the last ones I got were $10 for a gallon size pot in bloom, so they're not all that expensive. Now, if you were looking at buying Cypripediums, yes they are extremely expensive, but they also would probably be hardy to your area. ( maybe even grow wild near you!) I think they are native to much of the Northeast US and are also found in the Pacific Northwest.
Here are some pots of my Spaths from Lowe's:

Mother Raphaela, I echo what Elaine said, Spathoglottis are warm growers and simply would not survive in the ground outside in your region.
Elaine mentions my Bletillas - in my zone I am able to grow them right against the South facing house wall and I mulch them well in Fall too. Mine have been coming back year after year and they do multiply right along the house wall, not so much into the border.
To tell you the truth, I have not measured the pH in that spot, think regular potting soil (Miracle Grow) which I add every couple of years to the soil/ I just spread it lightly over the patch of emerging plant tips.
If you were to give Bletilla striata a try, you might want to plant them into a very protected sunny spot, this way you might be able to grow them.

I live in zone 4-5 and I can't grow them outside even in a warm spot so I grow them in pots. Right now they are about 6" high.

Do you keep them with your Cymbidiums, Kathy?

Thanks for the feedback, Guys! Sounds as if that slipper never stood a chance...

mmm -- if Kathy can't grow them where she is in MA, they won't make it here. I probably have enough plants I'm nursing through indoors (including my amazing Crinum lily ) without taking on orchids. Maybe someday, when I get to retire from bookkeeping...

Hmm, if it was a slipper, it may yet re-emerge! That's what the hardy native Cypripediums are. Keep an eye out for it.

Cypripedium acaule come up in May! Major blooming time for NE Pennsylvania is just shy of Memorial Day!!
Now we are talking about a totally different "animal"!!

I want to try Eulophia petersii one of these days..seems the right kind for our dry area and will blend in nicely with my succulent collection.

Ursula, yes, I am growing my bletillas with my cyms.

thanks Kathy!

This is a Swamp Orchid Phaius australis that I photographed last week. These are the first I have found here on the island. Their localities are mostly kept secret because their scarcity in the wild is apparently due to illegal collecting. Even so, clearing of swamps, wallums and heaths must take much blame. It is listed as Endangered under Federal and State legislation.

My photographs, however, are of old and not fresh blooms. I was too late onto the scene. I notice there are no photos in our database - should I still add them despite the flowers not being fresh? It is a very big terrestrial orchid: this flower spike is about four feet high and the leaves reach as high.

I noticed today several specimens for sale in a nursery. These ones come with a certificate of permission to possess because they have been allowed to be collected from habitat before it was legally cleared for development. Not from this State, Queensland, but the State immediately to the south: New South Wales. Hopefully this availability is taking pressure off wild populations.

How nice to have come across this one in its habitat!
I would add these pictures to the data base and then perhaps add a better picture when you are able to catch them next time perfectly open.

Wow, wild Phaius would be a thrill to find, Glen. Mine last a few weeks in the shady location they have, so I'm sure you'll catch them at a fresher stage next year, now that you know where to look.

Nice to see you back, btw.

Just monitoring my Eulophia petersii I got last Oct 2015. Right now still indoors here by a south facing window, our overnights is still chilly. Trying to see some signs if it is waking up:


I remember this part, it seems to have stopped whatever growing is going on in there since I got it in Oct:


I did not have a good shot in Oct of this part, nothing to compare it with. So I will just use this as starting point, seems like new growth:

Is this your typical orchid media, Tarev, or does this particular plant love to stay on the dry-side?

No, just for this orchid, it needs to be on this dry, gritty media.

Thanks for the continuing education, Tarev. Does it also like low humidity and high heat?

I have Eulophia petersii also (thanks to Tarev sending me in the right direction). People who have gone out and collected them talk about getting there by camel.

Mine is sitting in my greenhouse on the cactus end. It's not doing much - I think still dormant.

I found this photo of them in the wild:

https://c1.staticflickr.com/9/...

Daisy

Interesting, Daisy. Thanks.

Nice photo Daisy!

Ken, yup, that is the thing that attracts me to it, have read how it thrives on low humidity and high heat! The two things we have constant during late Spring to early Fall.