Bob Floyd will do a talk on repotting and culture in general. Joe DiCiommo will conduct a workshop on Cattleya covering

Doug Kennedy will demonstrate deflasking a lycaste, repotting and dividing miltonias and brassias.

Gary Schreiber’s workshop will focus on Paphs his title is ' Not all Paphs are created equal.'

Following the very good talk by Peter Decyk "Growing Under Lights", this talk compared lights to windowsills and greenhouses for implications related to orchid culture. It seems to be a common belief that greenhouses are the paramount growing situation for hobby orchidists. Good orchid culture results from extensive knowledge, keen observation and effective routines much more than your growing area.

Comparing lights to windowsills to greenhouses requires criteria. Constancy of the conditions, control of those conditions, initial and maintenance costs, energy consumption (costs), size, expandability, appearance, ease of use and the suitability for a variety of orchids were used for comparison. Lights were rated excellent or good on all criteria except for variety of orchids. With sophisticated light set-ups most orchids can be grown, but basic plant stands are more limited.

Windowsills, which were probably the first types of horticultural growing areas for exotic plants, were rated good on most criteria and excellent on energy consumption. The variety of orchids able to be grown on windowsills is greater than under lights.

Greenhouses, which originated to allow growing exotic plants more effectively than windowsills, were rated good on many criteria but poor for cost and energy consumption. Ease of use is lower for greenhouses than both lights and windowsills due to the extreme range of conditions that can exist throughout the greenhouse at one time or in the greenhouse over a day or year. Where greenhouses rate excellent is in the variety of orchids that can be grown. This increased variety results directly from the greater variability of conditions that can be found in greenhouses.

Effective orchid culture requires good watering practices and temperature controls. These factors are mostly dependent on the caregiver/hobbyist. Light is the defining difference between culture under lights, on windowsills or in a greenhouse. Estimating light levels is difficult due to the tendency of our eyes to compensate to "maintain the appearance of the same light levels".

Windowsill and greenhouse culture differs greatly from growing under lights in terms of the quantity and behaviour of light. Light set-ups are consistent for light levels but windowsills and greenhouses vary from hour to hour and day to day. Weather, obstructions, direction and the transparent material have a huge influence on the available light in windowsills and greenhouses.

Light travels in straight lines until it strikes an object. Light can be absorbed, reflected or transmitted through the object. Light is absorbed by the leaves to power photosynthesis, which in turn permits growth. When light strikes a clear, or nearly clear, material like glass at a steep angle (close to 90 degrees) most of the light travels through (transmission) but a small amount is reflected (never enters through the glass). However, when light approaches glass at a much lower angle most of the light is reflected and only a small amount enters.

The implications are that early morning light enters an east (facing) window. However, it should be noted that this light is richer in orange/red wavelengths and lower in violet/ultraviolet. As the morning progresses more of the light is reflected from the east window until eventually the window moves into the shadow of the house. For the remainder of the day the east window gives soft diffuse light. This means that an east window is most suited to less light-demanding plants. Conversely, a west window receives no direct light until afternoon and has more reflection in the early afternoon and most transmitted light later in the day. A west window is considered "brighter" than an east window of same design since the growing conditions are tougher (higher temperatures, lower humidity and the plants have used some of their reserves).

A south window is the brightest, with a north window being ineffective for orchids without additional light being added. A south window has its greatest light penetration from late morning (10 AM) to early afternoon (2 PM), when the light is richest in violet/ultraviolet. This window is much more effective at growing orchids that demand medium to higher light levels. Through the use of blinds (narrow venetians work well) and strategic placement of the plants according to their light demands all light levels can be effectively achieved. Light demanding plants should be nearest to the glass while lower light plants should be behind them (further from the glass) or located to the sides of the window area. (Note: under lights as the distance increases the effective light level drops quickly, this is NOT true in a window or greenhouse since the distance from the sun has not been effectively changed.)

Light set-ups produce very effective growing conditions with minimal cost and effort. Greenhouses, on the other hand, involve the greatest amount of effort, expertise and cost to produce effective results. Allowing more plants and more variety is the advantage of the greenhouse. But with these increases comes a greater time and money commitment.

Windowsills offer many of the advantages of the greenhouse but the effectiveness of light set-ups. Improvements to windowsills can increase their value to your orchids. A Bay window has three surfaces and projects out of the house’’s wall. Changing a straight window to a Bay window (of the same width) increases effective light, allows for cross ventilation and increases your growing area without sacrificing room space. A south Bay window admits effective light from early morning to late afternoon, 8 hours. If the side windows are casement style they can be opened for ventilation. Installing a shelf (ledge) that encloses the entire area will give you two to three times as much area with greater depth for arrangements. Inclusion of a "pebble" tray is useful to catch water and increase humidity locally around the plants.

If you wish to increase the light level in an east, west or north window, lights can be added. These lights should be on timers but you can also add a device that only allows them to operate on cloudy or low light days. This modification eliminates some of the variation in light level experienced in windowsill culture. These lights are supplemental and can be fluorescent or spotlights of the incandescent type. An added bonus may be that the lights will slightly raise the daytime temperature in the window.

Improvements to windows may involve installing new windows. Windows should be thermally effective, thermopane glass units of two panes are very good and available. Many newer windows come with argon between the glass and coatings to reduce heat loss. However, manufacturers also promote glass that has been constructed to reduce UV (ultraviolet). All glass reduces UV, which is needed for good plant culture. Avoid glass that is promoted as reducing/excluding UV from entry. Ensure that the window is constructed of material that resists rot and decay. Your growing area has high humidity and water spillage. Whoever installs your window should use extensive measures to reduce these problems.

Remember that good culture depends on you, more than what your growing area is like.