Question
To give the information I negected to give (sorry)orchid #1 is a Phalaenopis it's the one with the dieing leaf. Orchid #2 I believe is also a Phalaenopsis as it have the same leaf shape and texture. Orchid #3 not sure did not ahe a label and has a longer finner leaf with thinner texture than the others. Tehy were also reoped in Sphagnum moss as thats what they came in. Hope this helps!

Stephaine
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Followup To

Question -
Hi I have three orchids I rescued from my local home building center, they've been repotted and brought back from the brink of certain death and are looking alive and healthy. My question is that there a white mold growing on the medium, the plants were repoted when I brought them home as the medium was very wet and finely packed. How do I get ride of the mold or shold I just repot them again? the one orchid has a mature leaf yellowing and dieing off is this normal or should I be worried that the mold is doing damage?
thank you for your help!
Stephanie in Ottawa, Canada

Answer -
Hi Stephanie,

It was good that you repotted those orchids soon after you got them home, you definitely saved their lives. You did not mention what material you used to repot them in. Was it something with a fine texture or more chunky? Most orchids do not like their roots in fine textured potting materials but prefer a more chunky open mix that allows air to circulate around the roots. You also didn't mention what type(s) of orchids you rescued. If the roots are rather thick, then you want to use a very open mix while thinner roots you can go with a slightly less open mix.

Now about the mold. Mold or any growth on the potting mix is not goodness. Repot them again but if you use the same type of potting mix be prepared to repot annually.  Be sure to clean the roots prior to repotting as you don't want any mold spores tagging along.

Yellowing leaf may or may not be some thing to be concerned about depending upon what type(s) of orchids you have. Some orchids are deciduous and drop their leaves after about a year. Also, there are some orchids that produce new leaf growths from the top and the bottom leaf will slowly die and fall off. What you do not want to see is a leaf dying off where the leaf is still green but with a dark sooty mold at the leaf base. If you see this sooty mold, that would indicate a possible fungal growth which occured because there was water at the leaf base over night.

I wish I could have been more helpful but without knowing what type(s) of orchids you have, these are some ideas and things you can try. If you have the names or other questions, write back and I'll try to help.  

Good luck and good growing.

Jim Kawasaki
San Jose, Ca.

Answer
Hi Stephanie,

That helps! Thanks.  Also that they were potted in sphagnum moss.

I would suggest you take them out of the new sphagnum moss when you have some time and other potting material. Why? Sphagnum moss is good for 6 to 9 months then should be replaced because it breaks down so quickly when wet, if you don't mind doing that much work you can leave them in the moss. For the phals I would suggest a fairly open potting mix while the thin-leaved orchid a little finer mix. Many nurseries near my home carry orchid potting supplies but I'm not sure of those near Ottawa, Canada.  

As for the thin-leaved orchid, are there somewhat flattened bulbs? Were the flowers somewhat starry shaped with a large flattened center lip? If so, it may be part of the Oncidium family of orchids. If it is, oncidiums prefer bright indirect sunlight (leaves will be light to medium green), humidity above 50%, watered when the potting mix becomes almost dry, some air movement around it, feed it with a balance type orchid fertilizer but at 1/4 the recommended amount.

Hope this helps.  Good luck and good growing.

Jim