Just like the plant life in Osentowski’s greenhouses, his book is rich in diversity, useful material and beauty. Although not a straightforward how-to book, The Forest Garden Greenhouse contains a lot of practical information organized loosely by topic and by Osentowski’s life journey.
The forest garden greenhouses described in the book contain layers of life, from root vegetables, leafy greens and vining plants to climbing trees, as well as worms, chickens, rabbits and even fish. The idea is that each element complements the others resulting in a stable and highly productive ecosystem.
The book also has layers. You can just enjoy the beauty of the pictures — inspiring portraits of lush jungles (bananas and papayas inside Colorado greenhouses!). Or you can learn about the principles of permaculture, or specific information on soil and pest management.
As for greenhouse design, Osentowski doesn’t provide a recipe for construction. He believes each greenhouse is a personal statement (his structures have names such as Phoenix, Mana, Shree . . . He recommends you, “incorporate your passion into the building of the greenhouse.” In addition to the plants, his greenhouses include a hammock, sleeping platform, indoor archery range, sauna and ponds. The choice of building materials depends on what he can salvage.
If you’re considering building a greenhouse or improving the productivity of an existing one, you might glean several good ideas from this book, such as the following.
- Layer carbonrich material (straw, hardwood shavings) and nitrogen-rich material (green leaves, manure) on the greenhouse floor. Add red wigglers (manure worms). To protect this blend of a sheet and worm composting system, place pallets over top, cover these with plywood, and use this as a floor or walkway. After several months, you can harvest the worms (perhaps to sell) and the compost.
- Mining mycelium. To add more beneficial fungi to the garden and greenhouse soil, collect the bottom layer of woodchip piles left outside. Where the hardwood chips are in contact with the soil, they become inoculated with fungi which perform valuable roles in the garden.
- Use gabion walls — basically rock cages — to provide thermal mass and structural support.
- Make walls for retaining beds from pallets, gabions, corrugated roofing supported by rebar, or sandbags supported by rebar and covered with chicken wire and cement.
Perhaps the most valuable part of the book is the description of the climate battery design. It’s too complicated to explain in a review but basically, fans move air through tunnels that are buried in greenhouse planting beds but also extend to the top of greenhouse. The result: cooler temperatures during the day, warmer temperatures at night, lower humidity in the greenhouse, and warm, moist soil in the rooting zone.
- Janet Wallace