Question regarding green house and other plant related questions - Ask Extension
Dear master gardener,
My name is Nattawat Klomjit and I am also working at UMN hospital. We are about to move in to a new place that have more land...
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Question regarding green house and other plant related questions #931372
Asked May 11, 2026, 4:42 PM EDT
Dear master gardener,
My name is Nattawat Klomjit and I am also working at UMN hospital. We are about to move in to a new place that have more land and we would like to have a green house. I do have several questions regarding that. A bit of back ground, green house will be on the lake side and facing west. Our target plan would be: cactus, and some tropical plants: lime, lemon and may be camelia and orchid.
1. We are thinking about 12x10 feet size green house and likely will place them on the concrete ground (already there before we move); is it a good idea to have that ground? Would it be difficult to insulate?
2. How much does it cost to maintain the temperature and upkeep on average monthly to have green house that size
3. What is the best method to heat green house, electric, propane? and which one is more cost saving?
4. I am thinking about cherry blossom and rhododendron/azalea for MN, do you have any varieties recommendations and also where to buy those?
5. Wondering if there is any bonsai resource or courses recommended?
Sorry for a lot of questions
Really appreciate your help!
Hennepin County Minnesota
Expert Response
Thank you for writing.
I have a 4 foot by 8 foot plastic greenhouse that I bought as an on line kit for $500. I added a cheap space heater and lights and it extends the growing season by about a month at the beginning and end of the season. It is on a two inch concrete slab.
The more ambitious you are the better insulation, heating, and lights you need. A west facing green house would need LED lights to mimic 16 hours a day. It would need insulation to keep tropical plants warm. It would need water and drainage. Such a unit could could cost $15,000-30,000.
I suggest you become a member here https://www.hobbygreenhouse.org/ and follow the news of the Pennsylvania chapter. We are zone 5a.
I have a 4 foot by 8 foot plastic greenhouse that I bought as an on line kit for $500. I added a cheap space heater and lights and it extends the growing season by about a month at the beginning and end of the season. It is on a two inch concrete slab.
The more ambitious you are the better insulation, heating, and lights you need. A west facing green house would need LED lights to mimic 16 hours a day. It would need insulation to keep tropical plants warm. It would need water and drainage. Such a unit could could cost $15,000-30,000.
I suggest you become a member here https://www.hobbygreenhouse.org/ and follow the news of the Pennsylvania chapter. We are zone 5a.
