What are the benefits of greenhouses and how do they work?

Question

What are the pros and cons of greenhouses and how do they work? What are their limitations? How does one plan and build one? What is necessary to maintain the plants inside optimally? I am in Central Florida.

Answer 1

It is a broad question. Already most of strict question have the answer of "it depends", so you can imagine that: What benefits? It depends.

When you need a greenhouses, you will knows it (and so the benefit). Start without greenhouse. When you see that you miss something, check to improve your equipment. It really depend on what and how do you do things.

On older time, a stone wall and shelter (just soil or and leaves) or bring it in some shelter building were the only option available.

With better plants (and availability of clear glass), nobility started with orangeries: it was so fashionable to have oranges on Northern Europe. Orangeries were buildings with large glasses, to shelter the oranges in winter. From there to green houses (new technologies, new exotic plant to show), it was a short step. As you see, the need to have exotic plants was the driver. [Note: if you go on greenhouses on botanical garden on hot summer, you probably find that they are colder then outside].

So:

• Do you have exotic plants, which requires controlled temperature?
• Do you have plants which do no like freeze (or low temperatures), so you need a shelter on winter? Or do you produce flowers and other plant to be sold and used inside houses?
• Do you sell vegetables, so you want to sell part of them earlier? (normal green house) or on winter? (heated green house)
• Do you produce organic vegetables or other delicate vegetables, which should be protected from weather (wind or (heavy) rain)? Also in this case there are some sort of greenhouses (tunnel), mostly a plastic that cover the "ceiling".
• Do you produce many seedling in winter? (or just do you want to advance the final plantation).
• Are you performing scientific experiments? (so controlled environment, possibly not just temperature, but pollinators or explicit spread of diseases).
• ...

Note: for many residential uses, a small plastic, maybe attached to your home, could be enough. You need to have a problem, than check possible solution (and greenhouse could be one of that).

Answer 2

In your location you may be looking for a shade house rather than a glass house. The purpose of a glass house is to shift your growing location several hardiness zones to, in your case, the south i.e. closer to the equator. But in your location you're going to have overheating problems in summer and you'll need to keep misting your plants to cool them down.

It looks like your region has the lowest temperature of about 35 F or 1.5 deg C so you don't really get bad frosts, so you don't even need a green house to protect winter vegetables.

So, the main use would be a small greenhouse to get plants started before spring. A greenhouse will give you a few weeks start on getting your seedlings to a point where you can plant them outside unprotected.