Sandy if these subjects are not the kind of experiences you have yourself I would not do the class. Anyone can read about the subject themself. Most people who attend a workshop on a subject expect the instructor to have personal experiences to pass on. Al

I a bit baffled at your response. I owned and operated a sizable greenhouse for over 20 years and have built many smaller structures for specialized purposes such as a cool house. I have been raising, propagating, selling and talking about houseplants for 40 years. I have no particular lack of information on either subject. I am asking what questions a novice would be most interested in getting answered. I doubt they would like to hear me spend much time on the technical aspects of aluminum strips in greenhouse glass, the formulas for costing a greenhouse full of boston ferns or the uses of commercial refrigeration systems to produce hundreds of bareroot shrubs when the session is restricted to home or hobby greenhouses for beginners. What did I say that led you to think I was clueless? Sandy

Houseplants hasn't been done in a while and greenhouses are a completely new topic.

It's the way you wrote the question. I too thought you were a Gh novice. When I went back, and Re-read the question, I now understand that the topic is a new lecture for your MG extension.

I am sorry for misunderstanding your question. Apparently you feel that because of your commercial experience you do not know what a greenhouse newcomer might need to know. As a greenhouse hobby grower I would suggest you delve into the light levels needed for optimin growth in a greenhouse. If your greenhouse is sited in a area which causes the use artificial light the cost in a greenhouse invironment can be 1000 watts or more and an unexpected expense. The cost of heating is always primary and the cost of light is often overlooked. Al

Disease and how to prevent it is a huge issue.

"and greenhouses are a completely new topic" That is the line that made me think you were a novice at greenhouses as my mind automatically read "and greenhouses are a completely new topic (to me)"
Seems I wasn't the only one thrown off. From the rest of the post I gather you are trying to predetermine what the questions the class might have and what they might be most interested in. My brother had a greenhouse once and from my observation was it was like having a baby in diapers so my desire for one severely diminished although they are necessary and still sought after by many. If I did have a greenhouse I would want to know about watering schedules and methods, fertilizing or not and rates, methods of propagation. When to start seeds to bring starter plants to market. How to cool the greenhouse in the summer, how to heat it in the winter, what plants should I focus on to start with, how to price them and where to purchase supplies? All that and more.

Thank you for your input. For the first discussion (I prefer a conversational situation rather than a strictly one way lecture) with 41 interns, I explained the types of greenhouses, materials used and the necessary and optional equipment used. Location, temperature control including temperature alarms, flooring, ventilation, shading materials, water and electrical needs were addressed. I supplied web sites of basic routine and sources and two printouts of plans for current designs.
Eddie, I don't know what the problems your brother ran into were about but he may have been unaware of what problems could show up. I have always found that expecting difficulties and knowing how to deal with them on short notice or avoid them made the day to day operations go smoother. Sandy