Does anyone currently operate a greenhouse including trees? I've long nurtured the dream of having citrus and other warm-weather trees in my zone 5/6 area. Dwarf trees would be fine to an extent, but slightly larger ones would be nice too. So, to that end, has anyone tried this? I can only imagine it would be a nightmare to keep heated having such lofty dimensions.
The Ott-Kimm Conservatory is a greenhouse that has been operated as an ecosystem with no inputs for the last 35 years. It is full of fruit trees, in fact the type of greenhouse that I prefer to build is ideal for warmer climate fruit tree cultivation as well as propagation. The Conservatory is to my knowledge the longest standing example of a balanced ecosystem enclosed in a greenhouse. We are currently in various phases of construction and establishment for 4 more 1,000+ square foot Earth Powered Greenhouses in it's likeness. Each of these will also be largely for cultivating warmer climate fruit trees.
Self-fruitful Semi-dwarf Fruit Trees are what we have had the most success with. True dwarfs are often not the greatest fruit and don't produce well. Semi-dwarfs are grafts on dwarfing root stocks, so you get the propagated variety of fruit and it's productivity, but overall plant growth is restricted by the rooting stock. These also reach maturity the quickest, although their lifespan is the shortest. That the fruit trees are also Self-fruitful is even more important. This means the variety can pollinate itself. In a greenhouse environment this allows you more diversity, leading to a more resilient and healthier ecosystem. With this kind of design we can grow citrus fruit in a zone 3/4 area. When the temperature remained -20°F or below for 2 weeks (going well below that) the Conservatory cooled to 15°F. The Earth Powered Greenhouse that we just completed remained 31°F when it was -20°F outside. This is without the stored heat from a summer growing season, nor the thermal buffer that humidity provides.
That's very impressive! I can't even begin to imagine how much that must have cost to set up! When you say "no input", does that mean that you also haven't planted new plants in the meantime? What all does "no input" entail?
I'll be looking into semi dwarf trees, they seem very promising!
Just put the cards in their christmas stocking and PRESTO! They get it now! It's like you're the harry potter of permaculture. richsoil.com/cards