Greenhouses are an excellent way to prolong your growing season if you live in a cooler area like I do, or to control your climate for your plants in warmer climates. It also gives you the option to grow more exotic plants or plants that require attention.
When making plans for your greenhouse you need to decide what the main goal for you plants are. Are you starting plants or growing tropical plants? Are there certain climate controls you will need or an additional area that is cooler and darker for plants. These decisions will determine your climate you will set up and the plants you grow.
Over all its best to choose plants with the same climate control needs. It’s less work and your plants will thrive. If I do chose a plant that requires additional heat I will set up an additional mini greenhouse within the greenhouse by using clear plastic and a frame.
Most greenhouses are used for three projects, starting seeds, growing houseplants or growing perennials.
In general perennials require cooler winter conditions. They need a dormant period to rest before the next growing spurt. I have a section in the back on the greenhouse for perennials that is sheltered with less light and not heated like the other area.
Annuals are fun to grow in the winter. The color they add to your greenhouse and house just make the winter months go faster. I mix annuals in with extra houseplants and plants from the porches.
One point to consider when choosing plants is plants that like high humidity. Greenhouses trap in moisture and make the atmosphere humid. This makes the perfect climate for most tropical houseplants but cacti and succulents suffer in this climate.
It’s also wise to select plants, which require high amounts of light. Greenhouses allow filtered light in and plants that love light thrive. Only choose low light plants if you can create a shady corner in the greenhouse.
Research the temperature needs of plants before you choose them and pick plants, which have similar needs. If you choose plants with different requirements you will either have to make mini greenhouse areas or spend more on heating and cooling systems.
This site has a few suggestions for plants for greenhouses: http://www.gardening-howto.com/greenhouse/suitable-plants.htm
I close my greenhouses from Dec to January for heating reasons. Its cold in Pennsylvania and I don’t want the high heating costs. I will grow cool weather crops and plants but any plants with more heat requirements wait until February or March, depending on how severe the winter is.
This year it’s been relatively mild so my greenhouses are being cleaned and should be able to be heated with solar power alone. My first greenhouse project will be to move my tomato and pepper plants outdoors to the greenhouse and to start more greens and some of my seeds.