Passive Solar Greenhouses
Permaculture Tour 2012 is Here
Plant Polycultures-A Garden with Many Functions
When designing a food-bearing landscape, one of the first things to decide is what plants will go where in the growing space. Most of us have heard of companion planting, square-foot gardening, perennial food forests, and inter-planting. Creating a polyculture combines many of these strategies and more. In this issue we will look at the planning stages of a polyculture and the elements necessary in creating a resilient and productive one.
In books and all over the internet, we can find loads of advice on which plants grow well together and which ones do not. Some of these combinations work fairly well, while others have yet to convince me. Providing mishmashes of different vegetables is not our purpose here. Since climates, pests, soil types, and our own tastes vary, we want to discover what works well in our own gardens, and we can do so by choosing plants not by species, but via the function they perform in the landscape.
Keep in mind that perennials are very useful in a polyculture. We can plant only annuals, but this is asking more much more work in the long run. Here is a list of functions (not necessarily in order of importance) that we want to include in any polyculture. A quick web search under any of these topics will provide numerous plant types suitable for any garden. If we have balanced proportions of plants in each of these categories, we are off to a good start:
A. Nutrient Accumulators
The thick and/or long roots of these species plunge far into the earth to extract minerals and other ingredients necessary for all plants to thrive. Usually after several of these species have matured, they will begin a natural decline in numbers once their job is complete. Examples of these might include: plantain, alfalfa, dandelion, chicory, and mustard species.
B. Nitrogen Fixers
In any guild, it is crucial to have plants that fix nitrogen in the soil. These plants have a specialized ability to extract nitrogen from the atmosphere and place it into the soil. Nitrogen is a necessary element in all plant development and speeds the growth of all plants. Nitrogen fixers include plants such as clover, peas, potatoes, Siberian pea shrub (caragana arborescens), lupines, and any leguminous or bean type plant.
C. Mulch Plants
We use these plants for building soil, preventing erosion and evaporation, and protecting and shading the roots of others. In this category we often might include a process called “chop and drop”, which involves cutting the plant down at the soil surface and leaving the greens on the soil to eventually decay. The roots either come back as another plant, or decay as well becoming part of the humus layer of the soil. The “chopped” parts of the plants also become a thick and fluffy layer on top of the soil. Some examples for mulch plants are rhubarb, nasturtiums, Jerusalem artichoke, mustard, oats, and barley, and virtually any soft-leaf plant that decomposes quickly.
These are any plants that will attract beneficial insects to your site (insects that will either pollenate to produce fruit or will consume/deter pests). Insect attractors include dill, coriander, thyme, yarrow, fennel, and believe it or not, dandelion.
There are other smaller categories, such as those which provide animal habitat and those which act as soil fumigants, but beginning with the four listed above is a good start.
Additionally, it is wise to use any plant that is able to perform more than one of the above jobs. This is what we call ‘stacking functions’. Examples of this would be using clover as both a mulch plant as well as a nitrogen fixer, or growing comfrey as a nutrient accumulator and to fix nitrogen or even using rhubarb as a mulch plant and of course a human food.
Finally, we should keep in mind the actual space each plant takes up in the landscape—both above ground and below. This is why we try to arrange plants in a polycultured landscape, creating a ‘mosaic’ in which generally we keep similar plants away from each other as much as possible. Doing so will minimize competition for sunlight and soil, as well as confuse pests (or at least keep them confined to one or two plants.) As in any form of permaculture, the more functions we can cover off each time, the more resilient the system and the less energy it will consume in the long run.
Passive Solar Greenhouses Beginning to Appear in Calgary
Many people protest the short growing season in Southern Alberta. With some techniques such as raised beds, cloches, and mulching, we can usually expand the less than 110 frost-free days, but some people are taking things a little further. A passive solar greenhouse can expand the growing season by several months without the use of external power. Unlike traditional greenhouses, the idea here is to trap solar radiation within the structure to create the appropriate growing conditions for most plants. So how is this accomplished? Think of what happens when we leave our vehicles parked for a while on a sunny day. Even on a day reaching a mere 15 C, the interior can be quite hot. This is because the glass allows the solar radiation to enter, while the rest of the car absorbs this heat and insulates against heat loss. Most greenhouses lose heat through any side of the structure that faces away from the sun. What we are trying to accomplish with the passive solar type is to minimize heat loss. To do so, the north and sometimes east and west sides are built with walls containing good insulating materials—sometimes with an R-value greater than most homes. On the opposite end of the scale, adequate ventilation is a must especially for the warmer days of summer. There are many other modifications that can be made, such as the angle of the glass and materials used as well as covering the whole structure with insulated blankets in the coldest days of winter. Nevertheless, experimentation with capturing and holding heat and moderating temperature so that plants might one day make it through our severe winters, continues. The following are links to a couple that have popped up in Calgary. (I also have a friend (no link yet) who has just installed a solar heated shower in hers).
Verge Permaculture, Just completed the addition of a rocket stove to this one…
This one by Joshua Baker of Radicle Routes was constructed using reclaimed materials…
Calgary Permaculture Tour 2012 is Here
For those not already in the know, on Sept 1, 2012 Prairie Sage will be conducting a one day tour of Calgary's most prominent and exciting sustainable and regenerative living sites. Details of the day are as follows...This excursion will be both educational and fun! Leave your vehicles or bicycles at our meeting place (The AREA 12:30 pm) and be escorted around Calgary for a tour of such notable places as Verge Permaculture, Patterson Springs Farm, The AREA and more. The tour will conclude in the evening with a locally brewed wine/mead and dinner at the AREA in Inglewood. More information can be found HERE!
Building Soil Naturally
Wildwood Garden Starting to Resemble Design
Kids Workshop June 9, 2012
The Basics Of Building Soil Naturally
Every spring I have people ask me where the cheapest soil in town can be found. Of course I let them know the company that sells it at the lowest cost (that I am aware of). However, what I should be telling people is that the cheapest soil is actually in your own backyard--or at least it can be made there if you’re willing to be patient.
In permaculture, just as in nature, good soil is made by two directional energies: one flows from deep beneath the soil toward the surface, and the other flows from plant branches downward to land on that surface. In other words, all the natural mulch such as leaf litter, flower petals, and other plants materials that land on the ground will decay and turn into a fluffy layer of humus. At the same time, certain plant roots plunge deep into the earth to mine minerals and bring them up to the surface. If we allow those plants to eventually decay, the minerals will be left there for other plants to access them. A technique to speed this up is called “chop and drop”, where we allow these thick or long-rooted plants to grow to a certain size and then chop them down and leave the greens on the soil. The roots decay into “fingers” of humus and the greens also decay on top of the soil. The idea is, you throw nothing away; everything is returned to the soil. Helping the decay process are soil microbes, which digest organic matter and return it to the soil in hummus form. If your garden is used to constant input of pesticides and chemical fertilizers, there will not be as many microbes available for this process. This is where patience is vital. The soil bacteria and macrofauna will multiply if left to do so, making the whole soil creation process a lot more efficient in subsequent months and years.
The problem is that the type of gardening I’ve talked about so far mainly applies to perennial beds. As most people like to do vegetables, which are usually annuals, nutrients are constantly being removed without being replaced. So a bed that is 100 percent annuals would require a whole lot of compost or fertilizer of some sort to replenish those nutrients. This is why we always plant polycultures—the more plants and plant types the better. In nature you will never find an ecology made up of only annuals. In addition, perennial gardening does not mean that we need to stick to fruits. There are many varieties of vegetables which come back year after year. Examples of these are: Asparagus (zone 3), globe artichoke (zone 3), fiddleheads (zone 3), Chinese mountain yam (Zone 5), wild leeks (zone 3-4), garlic chives (zone 3), lovage (zone 3), Turkish rocket (zone 5), Groundnut (Apios Americana) (zone 3), Good King Henry(zone 3) and Rhubarb (zone 1), just to name a few. There are many more to add to this list, and many more to experiment with. If you still want to interplant some annual veggies to the landscape, then go for it. Some of us find it a little difficult to live without our crunchy carrots, etc. Just remember that when you pull the entire plant from the ground, the nutrients must be replaced in some way. If those carrots are surrounded by perennials raining organic matter all around them, then it will be less difficult to replenish soil.
Wildwood Garden Starting to Resemble Design
Members of the community of Wildwood have been hard at work since about mid-April on their community garden which uses permaculture strategies and design throughout. There are about 500 square feet of terraced wicking bed space so far which will drain into the swales of the lower leaf-shaped garden. There is much more work to be completed, but it will be done in stages. Some wicking beds are ready for planting, and the remainder should be near completion this weekend. Anyone wishing to volunteer and pick up a few pointers on permaculture is encouraged to drop by especially on weekends 4411 Spruce Drive Southwest, Calgary, AB
Gardening Workshop for Kids!
On the morning of Saturday, June 9 I will be doing a free children's workshop with "Kids Grow" at the West Hillhurst Community Garden where children will learn a little about plant guilds and be encouraged to participate in helping plant a small plot in the area. For more information, please contact Tamara with Kids Grow email: firstname.lastname@example.org or Ted Bahr with Prairie Sage Permaculture. Thanks and Happy Growing!
Ted Bahr is the founder of Prairie Sage Permaculture. MORE