Botanical Gardens - Orchid lover's dream

[jmmehler]

This year, the Birmingham Botanical Gardens has been renovating their exhibition greenhouses. All their plants have been relocated to the working greenhouses. Currently, they do not have any staff with orchid expertise, so they asked our Alabama Orchid Society for some volunteers.

I stopped by there this morning for an initial inspection. Rather than go at it with just my own ideas, I’d like to solicit some advice on some very specific topics.

Water conditionsThey use city water, which seems to have a very high mineral content. Most of the orchids are covered in white residue. On the one hand, I realize this is not good. On the other hand, the overly rotted medium that the orchids are in, probably create enough acidity to counter the high PH in the residue left by the water.

Greenhouse ConditionThe ‘growers’ Greenhouse is in good condition. Phals, paphs, & Phrags are in a section under shade cloth. They will soon remove that cloth, as the winter will bring less light. They have working heaters and ventilation. Humidity level is very good. Only select staff waters the orchids, and they will be getting some training, which will include the fact that recently transplanted orchids should require more water than those in rotted media.

PlantsThere are several dozen phalaenopsis in desperate need of repotting. Would appreciate comments on;
• Choice of bark mix, or moss.
• Was thinking of a diluted vinegar solution to wipe down the leaves, and then to spray in order to begin to eliminate the mineral residue

There are dozens of cattleyas and dendrobiums in rotted medium, also covered in mineral deposits. I lifted up a gigantic dendrobium whose root system had completely rotted out. While the medium was lava rock, it was so old that the algae, roots, and other debris kept it too moist. I’m tempted to over winter them in empty clay pots. Could use any and all input

There are hundreds of paphs, phrags, and oncidiums all seem very happy, with completely drenched roots and rotted medium. Operating on a large scale, they have mixed their own paphs medium based on a recipe they found, using commercial quantities of bark, expanded rock, and moss. Looks good but they haven’t started using it yet.

There are many Bulbaphilums (or as we say here in the South 'Bubba' philums. The giant ones with the 2 - 3 foot phalaenopsis looking leaves are in hanging baskets and look good even with the mineral residue. The smaller varieties are on tables and don't look so good.

Vandas are hanging in baskets and are unremarkable.

Obviously this is much more work than one person can do on a part time basis, but I figure on coming in a couple of times a week, on my way into work. Weekends may not be available at this time. Would also appreciate any ‘plan of attack’ strategies.

Thanks