When purchasing a new plant, don't let it sit around for any length of time. Get it out of the pot it is in, change the medium out and watch it hopefully bloom and become a phenomenal specimen. I do realize there are occasions where you can leave your new orchid in the pot it came in; but understand this, you really have no idea as to how long the plant has been in the present pot (usually plastic), how long it has had shredded packaging material taped to the top of the pot and how moist (saturated) the potting medium is.
Most growers use bark, coconut pieces or moss when growing their inventory. As I just mentioned, sometimes it is advantageous to leave things as they are; but there are often times you should change everything as soon as you bring it home with you. I do not fault any of the growers for their methods of packaging. Very often, what they do not sell is shipped to the next destination (show) and usually restock what they are short of. Many of the plants are in plastic and are watered prior to having a packing material (shredded paper) taped to the tops of the pots. The plants will not dry out that way. However, keep in mind, bark and coconut are an organic growing medium and will hold moisture very well. Being in plastic with very little drainage creates the following issue.
Most growers use bark, coconut pieces or moss when growing their inventory. As I just mentioned, sometimes it is advantageous to leave things as they are; but there are often times you should change everything as soon as you bring it home with you. I do not fault any of the growers for their methods of packaging. Very often, what they do not sell is shipped to the next destination (show) and usually restock what they are short of. Many of the plants are in plastic and are watered prior to having a packing material (shredded paper) taped to the tops of the pots. The plants will not dry out that way. However, keep in mind, bark and coconut are an organic growing medium and will hold moisture very well. Being in plastic with very little drainage creates the following issue.
Angraecum Lemforde White Beauty
I recently purchased an Angraecum Lemforde White Beauty at a local orchid show. It was in a four inch (10cm) wide plastic pot with minimal drainage (a small opening in the bottom). The medium appeared to be a fine red bark that looked newly applied and was very clean. Upon tilting the pot to get the plant out of its container, the red bark material spilled out showing me that it had been just a thin layer covering the actual medium. After working the pot by squeezing it completely around its circumference, the plant was liberated from its container.
The first thing I noticed is that the root system was very well developed. The issue was the medium used was all coconut pieces (holds a large amount of water) and was extremely saturated beyond being moist. With the poor drainage and abundant amount of water, the root system was starting to show signs of decay.
Basal Section of Angcm. Lemforde White Beauty
Organic growing materials break down or decompose. That same medium when saturated for long periods of time will decompose at a faster rate. With poor drainage and no air giving the root system an opportunity to slightly dry; there is a better than good chance the roots will begin to rot or start to decay themselves.
As long as the roots are exposed to the saturated medium, it is only a matter of time before the velum material surrounding the actual root will begin to decay. Usually the root material will start to turn black or darken drastically. The image below show several area where this decay has started taking place.
Beginning Signs of Root Rot
I removed the original coconut medium and lightly washed the decayed material out of the root system. As much as I talk about NOT messing with the root systems of most Angraecums due to their sensitivity, I cut away all of the infected root to try and eliminate the rot from spreading. I treated the entire root system with a topical fungicide (Physan 20) and then placed the plant in a six inch (15cm) wide clay orchid pot (they have the vertical slots cut into them on three or four sides).
Most of the new potting mix was non-organic such as charcoal, perlite, sponge rock, 1/2 inch (1.3cm) diameter clay pellets and a small amount of tree fern material with about a 10% amount of coconut pieces (to hold a small amount of moisture).
I did not water the plant for three days, giving it a chance to dry some what. When I did water the orchid for the first time, I used a systemic fungicide (Thyomil) in the water to give the plant a better opportunity to fight off any further development of root rot. I am currently keeping a very close eye on my new Angraecum Lemforde White Beauty. I will give an update to its condition in about three or four months.
You can check a new plants root stability before purchasing it by using your thumb and forefinger. Gently grab the base of the plant near the surface of the medium and gently wiggle it. If the plant does not really move much or at all, the chances are good the the root system is solid. If the plant moves freely, there is always the possibility that there is an issue with the root system. It is always in your best interest to re-pot ASAP after purchasing a new orchid. If there is an issue, don't hesitate to talk the the grower where you got your plant. If you talk to him in a reasonable amount of time, he will or should make good on the issue.