Designing a Permaculture Greenhouse
Establishing and maintaining a diverse annual garden can seem like an overwhelming task. Jerome Osentowski offers a surplus of solutions and techniques with The Forest Garden Greenhouse (Chelsea Green Publishing, 2015), on designs which will help keep the garden greenhouse full and healthy all year round. This excerpt from “Off-Site Case Studies” provides examples of real life solutions to everyday greenhouse issues.
Red Butte Ranch
This ranch is a private, family-owned operation located just outside of Aspen, Colorado, at an elevation of 7,800 feet. EcoSystems Design was asked to help create a greenhouse and fenced garden to serve their home kitchen year-round. This greenhouse is a four-season, solar-heated and -cooled facility and grows annuals and perennials for diversity and production to feed a household.
At first we sent long menus of vegetables and fruits they could grow in a four-season greenhouse and outdoor raised-bed garden, asking for them to select their favorite foods to serve from their kitchen. There was little response to this because the idea of growing their own food in a cold climate is what enticed them at first, and they had not really thought through the details. It may also be true that they were wiser than we were, not wanting to limit themselves by making any selection at all! We decided to create a diverse indoor garden for the greenhouse, with summer and winter planting calendars and garden bed layouts and rotations of annuals for the outdoor raised beds, each of which was fitted with hoops and row covers.
Greenhouse Construction and Upkeep
The greenhouse sits on a 1,850-square-foot plot of land, and the greenhouse structure size is 24 × 36 feet, or 864 square feet. It is surrounded by an outdoor garden. The greenhouse seems small at first but produces very well for a small family and guests. The property is located at 7,800 feet just outside Aspen, Colorado. Depending on the year it’s either in climate zone 3 or 4.
At this point they don’t employ any full-time staff for the greenhouse and only one part-time overseer. Seasonally, spring and fall, they have two paid positions for twenty hours. They receive a couple of hours of nonpaid volunteer help monthly.
The greenhouse is made by Nexus Greenhouse Corp. in Denver; it’s their Zail model, with a gutter height of 10 feet, and contains an automated insulating and shading curtain across the glazed portion of the ceiling. The ridge vents are substantial, at 3 feet wide on each side of the ridge and running the length of the greenhouse, plenty for summer cooling. We oriented the greenhouse east-west and designed the roof slope to the north of the ridge vent to be insulated and completed on the outside with corrugated metal roofing with a rusted finish. We used corrugated metal siding on the inside surface.
Sections of the east and west walls, as well as the entire north wall and the south wall around the perimeter raised beds were all treated with the same insulation and metal-finished assembly. This limited our main heat loss to just the minimal area we needed to glaze for harvesting sunlight and created warm barriers to the cold everywhere else. This produced a beautiful result, with a match to the rusty metal featured elsewhere on other ranch buildings, but it cost a lot in special details where the metal finishes transitioned to and from the polycarbonate glazing and operable vent panels. Flashing of different shapes and sizes was designed to integrate everything gracefully, and the end result was pleasing to the owners, which pleases us.
During the first winter of this greenhouse, the ranch caretaker called me to say that the current polar shock was causing him to have to bring in a large propane tank and a construction heater to keep the temperatures up sufficiently for the plants. I was surprised that the original specified heater would be inadequate, so I visited to check. I found a very useful tool for this site visit in my infrared thermometer, which allowed us to detect cold spots at the gable ends of the ridge vents. We found that the insulation had not been installed there by the builder, and cold air was pouring in these edges like a waterfall. We quickly remedied the problem, and the greenhouse performed as expected, with just its little gas heater in the trusses.
A positive lesson we learned on this greenhouse project is the value an owner gets from hiring a skilled greenhouse manager, even if just for a couple of visits per week. They hired Stephanie Syson, who had worked with Jerome for three years at CRMPI, to visit the greenhouse for two half-days per week. The ranch caretaker, who was the original instigator and our liaison throughout the greenhouse project, has made it a point to be there whenever Stephanie visits so he can learn the delicate balances to be maintained among the soil, the plants, the insects, the sunlight, and the air to make their greenhouse productive of high-quality produce.
Stephanie is also responsible for the planning, implementation, and oversight for all seeding, planting, growing, and pest management.
When you walk through the Red Butte Ranch greenhouse, it is obviously healthy and alive in every season, with many annuals “gone perennial.” There was a dinosaur kale tree that grew to be 11 feet tall because the owners harvested it leaf by leaf, from the bottom up. Several Swiss chard plants have “trunks” 4 inches in diameter from being continually harvested for over two years. Most of the tomato plants are stripped vines except for the very ends, where leaves and tomatoes thrive, with thick vines traveling back and forth along the south wall, attached to wire frames just above the raised bed. As long as their indoor climate permits, these annual vegetables have lost any fear of winter and are becoming vegetable trees.
Here’s what caretaker and gardener Mark Van Alstine says about their greenhouse:
We close everything up in the winter, seal vents, and turn the climate battery on. We also have a gas heater for backup on cold nights. In the summer we have vents, fans, and a shade curtain to keep it cool. Everything is automated to ensure as close to the right climate without manual involvement, but a computer can’t beat a gardener’s sense of humidity and temperature.
We log the planting date of varieties of plants that are exceptional growers and save that for the next season. We keep records of what we plant and when to carry over to the next year if applicable. Year to year weather and variables fluctuate, so we can’t repeat the previous year exactly, but our records help our vision for next year’s planting calendar.
We use beneficial insects like ladybugs, lacewings, and parasitic spider mites. In addition, we also have insectary herbs. As an aesthetic request all the herbs are grown in the same bed, in contrast to spreading them throughout the greenhouse beds to expand the coverage of their defensive properties.
The realities of a greenhouse are the pill bugs and slugs. You can’t get rid of them, so we learn to make friends with them. We grow plants in pots till they are big and strong enough to be planted in the bed. Then we spray our plants with cayenne pepper to disinterest the bugs till the plant is strong and established. The plants we find most susceptible to the pill bugs and slugs are the peas and beans.
To help build soil at Red Butte, they integrate worm farms into their gardens and have horses on the property that contribute manure to their compost pile. In addition to growing beds, the greenhouse has a propagation table with growing lights.
Stephanie Syson provides personal training and consulting in addition to managing this and other greenhouses. At Red Butte Ranch they’ve recently opened up to giving people guided tours to show what they’re doing. Stephanie says she “loves to share with anyone, anytime.” Some locals come to help out, volunteer, and learn about greenhouses in the process. You can reference the Red Butte planting calendar in appendix E.
Red Butte Ranch, Aspen, Colorado
Owners: Bob and Soledad Hurst
Manager: Stephanie Syson, Dynamic Roots
Reprinted with permission from The Forest Garden Greenhouse by Jerome Osentowski and published by Chelsea Green Publishing, 2015.
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