Growing Orchids: December in St. Augustine
Based on Robert Scully's articles, courtesy of AOS

General Orchid Growing Tips Plants will continue to manufacture food during the winter, albeit at a reduced rate. Everything will occur at a slower pace until spring arrives so the need for water and fertilizer is reduced. Indoor growers: pull you orchid away from the window if its leaves are touching the exterior glass. Outdoor growers: keep an eye on the minimum projected temperatures, such as the hourly forecasts by zip code from Wunderground. Greenhouse growers: don’t allow daytime temperatures to rise too high before ventilating the growing area after having it closed during the night or during especially cold days.

Cattleyas Cattleya skinneri should be pushing its buds up into dried sheaths for a January flowering; do not cut the sheaths off or open them. Cattleya trianiae and its hybrids ought to be blooming for several months beginning now. Many Sophronitis hybrids typically flower this season. Laelia anceps, the Christmas orchid, will have well defined buds just waiting for nature’s signal to open.

Dendrobiums Generalizations are hard within this very diverse group. The winter resting dendrobiums of the Nobile, Seminobile and Callista sections (email us if you're not sure) can be kept dry and cool this month. Shoot for minimum temperatures of 40 F. Nobile type dendrobiums may show some swollen nodes on their leafless pseudobulbs and flowers may appear by the month’s end. Your other dendrobiums will also be resting up this month though not dormant. You’ll water these half as often as you did in the summer. Shoot for minimum temperatures of 45 to 55 F and 55 to 60 F for the biggibum types.

Oncidiums The mule-ear oncidium, Oncidium splendidum, and the popular thin-leaved type, Oncidium maculatum, should be producing inflorescences. Stake the Onc. splendidum inflorescence as it grows upward, but do not allow the tip to droop as you would for a phalaenopsis.

Paphiopedilums Some of the mottled leaved species like Paphiopedilum fairrieanum and sukhakulii bloom now. Keep their potting medium moist and avoid getting water in the pouch.

Phalaenopsis Groom and stake each phalaenopsis spike. Avoid excess plant movement while the buds are developing or the buds may blast (wither).  High humidity in a closed house can lead to flower spotting caused by Botrytis; provide supplementary air circulation with fans and/or increase temperatures above 60 F.

Vandas Vandas are starting to rest now. You can gradually reduce your watering to every other day and cut back on fertilizer. Ascocentrum aurantiacum may have some beautiful orange to yellow flowers in bloom by the end of the month.

Miscellaneous Genera The Catasetinae (catasetums, clowesia, cycnoches and mormodes) are going dormant now and their leaves have been yellowing and dropping. Restrict watering until the spring growth is a few inches tall. The jewel orchid Ludisia discolor will begin to develop inflorescences soon. Clean the foliage now before the inflorescences grow.