Here a two quotes from forum members, who were discussing Deppe's book, The Resilient Gardener.
"In fact, the most efficient use of a small lot is growing annual vegetables. That's where the maximum yield is... While some will argue that food forests do that, they are not as efficient per square foot. You can get a lot more calories out of a 100 ft x 100 ft garden of beans, corn, squash, & potatoes than you can out of a 100 ft x 100 ft food forest. Annual vegetables cannot be on the bottom layer because they need lots of sun."
"Once a 100 x 100 food forest matures, it produces significantly more annual calories than a 100 x 100 annual bed."
I have heard contradictory information about this. Now, even if the first quote is right, I think that forest gardens have a place, because of their resiliency, low inputs, and sustainability. Mark Sheppard's Farm produces less calories than a corn farm, but produces a balanced diet. To do that with a corn farm would require feeding corn to animals, growing vegetables, etc, which would lower the calories per acre so that Mark's farm comes out ahead.
So, can a balanced diet of perennials beat a balanced diet of INTENSIVE annuals? I am including animals in both systems, since unlike some others, I think animals are necessary.
And, I am talking about small scale production, so that each system would get as much care as it needs.
I believe that a lot of this is relative to scale.
As an example, I grew up in a suburban home that had a lot just over 1/3 of an acre.
If you deduct the front yard plus the house/garage/patio footage, the back yard was about half of it.
That would be sufficient to grow both annuals and perennials to feed our family much of what is needed.
Most urban/suburban lots are nowhere near that size.
Somebody with a backyard 20' x 50' would be hard pressed to plant enough perennials to really sustain a family with a varied diet. If you have 2 fruittrees and 2 nut trees, your diet will be sorely short of a healthy diet. With even 1/2 acre growing space, there is plenty of space to provide a healthy diet for a family, but as the space gets smaller, so does the variety that can be grown there.
Many permies don't consider annuals as permie crops (I am NOT one of them).
Annual crops can provide a wide variety of foods, and I believe that they should play an important role - especially on smaller lots, where the perennials are limited by available space.
Partly due to growth habits, annuals & perennials usually have different maturity periods. Most perennials are ready for harvest in the autumn (asparagus being a major exception), while annuals ripen from late spring into early autumn. Mixing annuals with perennials greatly extends the harvest season of fresh foods. Wouldn't it be a bitch if everything was ripe all at once?
Having fresh produce to eat for an entire season is important to me. And, almost all of it can be preserved. I feel that any food garden that limits or excludes annuals is not a true permies garden.
Another thing to take into consideration in discussions like this are the energy dynamics involved. Intensive annuals are classically Zone 1-2.....lots of management, lots of inputs, lots of effort for those high yields per area. A food forest is more like zone 3-4....the ideal here is a moderate, diverse yield with minimum input and effort. The food forest designs more closely resemble more mature natural ecosystems, whereas the intensive annuals resemble the flushes of annual weeds that come up in disturbance sites. I think that ideally, there would be more food forest type landscapes punctuated by small areas of intensive annuals, since this mimics what happens in nature most of the time. Instead, the human race with its overcrowding and greed has created essentially a global disturbance event, with its successive pulses of weeds.
The challenges for the intensive annual gardener are the same as those of the extensive annual farmer....where will you get the inputs and the energy/time needed to achieve consistent high yields? To even approach sustainability, one suggestion would be to source as many inputs as possible from the waste stream.....from resources which when elsewhere unused stand a good chance of becoming pollutants. Strict composting and recycling on site, including urine and humanure, seems to be one place to start.
I'm reawakening this thread since I've been doing a lot of thinking on this issue of late, and wrote up a little mini-essay.
Annuals are adaptable, and can quickly respond to change or disaster, especially with human intervention. Perennials instead have mechanisms to cope with change; they build reserves and may even go dormant till better times return. Annuals spend all their energy on production in on burst. Perennials spend the bulk of their energy on infrastructure and networking. Annuals give the most food for the least amount of space. Perennials give the most food for the least amount of time. Annuals are pioneers; perennials come later. Finally, animals by their nature create disturbance, and humans, even good ecologically conscious humans, create lots of disturbance. Annuals and short lived perennials thrive in this disturbance. (Some theorize that the reason annuals were domesticated, besides their large seed yields, was that they thrived around the trash heaps, bonfires sites, and camps of humans.)
Because of this, systems need both. An analogy would be to the human body, with its stable skeleton structure and its quickly changing microbial symbionts. The ideal percentage of annuals will change depending on conditions. If space is the constraining feature, annuals will play a larger role; if time, perennials. As conditions get wetter and warmer, perennials do better; in the extreme tropics, a system may be completely perennial. As conditions get colder and dryer, a system will become more annual and or animal/ grass based as storage for a cold season becomes more important. As a climate becomes more and more variable, annuals become more useful. Extremely harsh desert climates should not be farmed at all, and certainly not with annual crops; even there, however, much of the biomass is short lived annuals that spring to life with a passing rain. Thus if we mimic nature, we will use annuals to adapt to variable conditions, and perennials to provide long term stability.
Finally, annual agriculture is also part of our cultural heritage. Our literature is full of references to it. Hundreds of generations of our ancestors left their mark on the genome of our major crop species. This is a treasure we should preserve, even as we develop new paths to limit our ecological damage.
When thinking about annual/perennial proportions, I always remember the 80/20 rule taught during my first PDC: in the beginning of a natural system (or after major disturbance of some kind), 80% of your yield would be from annual plant activity, and 20% would be from perennial production of some kind. Once a regime has been firmly established and matured, the proportions will reverse. Very few natural systems have NO annuals, and I can't think of any without some kind of perennials (well, maybe lava beds).
Where I'm currently going with my pondering on this is: as climate change ramps up, we may discover that the violent swings in weather patterns will in fact encourage ANNUALS to become a more important part of our food supply planning. I'm watching huge swings in water, temperature, freeze and drought cycles on a yearly basis. This is stressing many types of trees and bushes past their production points, even into death from weakness and disease. Here in the Pacific NW, we are seeing massive damage to young Western Red Cedar (Thuja plicata) via drought. Big Leaf Maple (Acer macrophyllum) is simply dying left and right - huge old trees and young ones alike - and no one knows why. Massive swards of forests containing Doug Fir (Pseudotsuga menziesii) are actively being composted by armillaria root rot. If these late and early frosts and short but viscous heat and wet cycles stress our perennial elements too profoundly, then we will need to be prepared by having planted lots of varieties of different annuals - and be supremely reactive ourselves to attend to these high-yield but delicate parts of our food production systems. The book Farmers Of Forty Centuries, by F.H. King, clearly describes a historical pattern of heavy annual production that sustained huge Asian populations for, you guessed it, 4000 years. We may find ourselves in a similar situation sooner rather than later. Annuals, and human labor, would become paramount.
"It is, of course, one of the miracles of science that the germs that used to be in our food have been replaced by poisons." - Wendell Berry
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