Wednesday, August 19, 2015

Low Maintenance, Resilient "Food Forest:" A Case Study


There's a stretch of bike path in McHenry Illinois where the wild has long been attempting to reassert herself. It's a place where many come to forage on berries, wild fruits and vegetables, one I've written about many times as an "unofficial" community forest garden tended lightly by those who come to share in the harvest. 

And those who do harvest this site have much to share in. With almost no mainteance, the site produces a wide diversity of fruits and vegetables, including strawberries, black raspberries, blackberries, mulberries, chokeberries, highbush cranberries, particularly nice wild grapes, elderberries,  black walnuts, hickory nuts, various wild greens, mushrooms, milkweed pods, harvestable wild grasses, wild onions, grape leaves, solomon's seal, and probably many other things I'm missing. 



But the main harvest was the blackberries, mulberries, and black raspberries, which were plentiful and very delicious grown in this semi-shade. When would come here for berries, we'd easily fill up our own containers, and we'd very often see others foraging, too, some taking far more than we ever did.  

This site has long been in my mind as a model for edible forest gardens, since it perfectly demonstrates several important principles I seek to emulate in my designs. Many of these "principles" invoke the design of the historic, traditional "forest garden" systems  of temperate climates. In fact, since this site (and a few other "wild" systems like it) seemed more "successful" at providing usable space with high yields and very low-inputs than any planned "forest gardens" in my knowledge, it provided the theoretical basis (plant spacings, configuration, etc.) for our "low input" designs at Lillie House. 

So, lets look at this site and see what principles and patterns we can derive from it:

I. Designed and "hardscaped" for success. On the broadest scale, as seen from space, this "forest garden" represents a set of patterns of resilience, low maintenance and high productivity worth replicating. 


In this case, the most productive parts of our system lie in three "rows," along a bike trail and a creek, set between two parking lots. In many ways, this replicates the pattern of "hedgerows," a traditional forest garden system in Europe, that are often found along road ways. This pattern comes with a variety of benefits:
A. Light. This location and hardscaping mean that plant spacings are kept at a fairly open "row spacing," allowing plenty of light to penetrate into the system This means that even under a dense canopy of trees there's still enough light for plants like raspberries and blackberries to produce heavily. 
B. Access. Hardscaped access is maintained on both sides of the system, as well as along the trail down the middle. 
C. shelterbelt. This forest garden system provides a windbreak and shelterbelt that benefits the church to the east. It also provides shade along the sports fields and bike trail. 
D. Maintenance. In almost any garden situation, maintaining paths becomes one of the most intensive chores. In this system, the paths require very minimal care. Such paths could be designed to last decades in between maintenance inputs. 
E. Water access. In this case, deep-rooted trees and perennials have constant access to water through the creek. Even on dry sites, it might be possible to emulate this factor, giving plants access to natural water sources. 

II. "Stacked social functions." This "forest garden" has a good chance at lasting a long, long time, since it is integrated in with social functions which are valued and protected. The integration of social functions protects uses like "forest gardening," and ensures that valable plants won't be removed to make room for social space later. The more social functions can be integrated the better. 

A. Sacred/ritual/ceremonial space. This side of the "forest garden" is bounded by an outdoor ritual space and a picnic area  used and maintained by the church. 
B. Recreational space: This "food forest" area is also used for a bike path, sports fields, baseball, soccer, and other recreational activities. 
C. Parking. Yes, even parking lots can provide value to a forest garden. Foragers need to park, too. If we're going to use resources to maintain parking areas anyway, why not "double up" the impact of those investments to help produce food! Which brings us to:

III. The Principle of Incidental Maintenance. The best maintenance scheme for a food forest is no maintenance scheme. When we can plan food forests to be maintained incidentally, through other activities and uses, or by use alone, we come out way ahead. In this case, the "forest garden" is maintenaned prmarily by maintaining a set of parking and recreational uses. The most "energy intensive" maintenance is the mowing of the sports field, which would be done anyway. 



IV. North/south orientation. Again, this allows maximum light into the system. 

V. Multi-layered. Tall trees, shorter trees, bushes, perennial herbs, ground covers, root crops, vines and mushrooms all in one place. 




VI. Naturally Dense Spacings: While many modern planned "forest gardens" aim for the field spacings promoted by university extensions, when it comes to low maintenance I have learned that nothing beats naturally dense plantings. So long as light penetration is maintained through some means (such as integrated social space and incidental maintenance) plants in systems like this one remain naturally very productive despite natural tight plant densities. In reality, there is no available research to suggest that the "research based" plant spacings optimized for high-input monoculture cropping are transferable to low-input polyculture systems. However, we do have a whole history of low-input polyculture agriforest systems to learn from, such as the hedgerows and tapestry hedges of Europe, which are invariably planted in very tight naturally occurring spacings. 

VII. Planned for resilience. If the humans of planet earth all decided to shove off to neptune for a few hundred years, this particular "system" would almost certainly still be waiting for us when we got back, filled with fruits, nuts and vegetables. This is due to many of the features above, especially the long productive life of the hardscaping, which ensures the light penetration necessary to keep a productive, diverse understory. This is probably the most important feature of this system to learn from. It would actually take a large amount of energy over many years to destroy this system or even to make it less productive. As a point in fact, some government agency DID expend a fair bit of energy to reduce the productivity of the planting. When we visited this year, many trees (especially mulberries) and brambles had been removed. I don't know why this was done. But I do know it was done in vain. Already the brambles were making a come-back and young trees were racing up to the canopy to replace the removed ones. Despite the energy and money spent to reduce the functionality of this food forest, next year, this system is likely to be as productive and dense as ever! 

VIII. Maintenance-Free Plantings. One thing that seperates this "food forest" from most planned gardens, is that the naturally-occurring, "wild" plants require no maintenance. No one has to spray, weed, or fertilize to get high-quality fruit from this "forest." Meanwhile, we rarely stop to pick apples, pears, or plums from the multitude of planted fruit trees around town. If they haven't been sprayed into oblivion (orchards typically spray multiple times a month!) or otherwise maintained, then the fruit will usually be riddled with bugs and disease. Now, there are some great uses for buggy fruit! But, with all the perfect, beautiful "spray-free" fruit out there that requires no "cleaning" or processessing, even avid foragers like us will rarely bother with "wild" apples. Now, this doesn't mean that you shouldn't have an apple tree in your forest garden, just that if you do, expect to "work" to get clean fruit. And if you balance those "intensive" choices with lots of fruit that will perform well without additional work, you'll probably be a lot happier for it. 


Of course, with a little thought and work this unofficial "food forest" could be improved and expanded to become an amazing "official" forest garden. More public uses could be integrated in and a greater diversity of food plants included. But, in the other direction, there are many things that our official "food forests" could learn from naturally evolved, resilient systems like this one.  


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2 comments:

  1. Thanks for sharing your observations . I was struggling with the aspect of future plant density in relation to maintenance in the design I am currently working on. This article gave me the inspiration I needed at the right moment.

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  2. Thanks for the feedback and encouragement! For a variety of perspectives on planting densities for food forests, you can also check out this post here: http://lilliehouse.blogspot.com/2015/04/establishing-food-forest-garden.html

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