Food Forests, Part 6: Diversity, or Picking a Garden Salad

One benefit of a single crop farm is that it isn’t hard to remember what it is that you are growing! Most of that single crop is sown at one point in time, grows at about the same rate and is then harvested at about the same time. 100% too easy, well apart from all of the very real problems created when growing a mono-culture….

Permaculturalists, on the other hand tend to grow poly-cultures which is simply growing a large number and variety of plants at the same time and location.

Poly-cultures in agriculture have a number of benefits including:

  • The sheer number and diversity (size, shapes, types, sub species, etc.) of plants makes it a confusing environment for insects and other herbivores which may otherwise breed large populations in a mono-culture and possibly eat the lot (or a large percentage);
  • A diversity of plants means that it will attract and provide housing and food for many predator insect species and birds which prey on insects which would otherwise eat the plants that you are trying to grow. In a mono-culture the farmer applies insect sprays to kill off any large and unbalanced insect populations, which only ever bred up in the first place because they were given the opportunity to do so, due to the mono-culture environment;
  • Each plant will have different nutrient/mineral requirements/demands on the soil. In a poly-culture, plants can harvest nutrients/minerals which then become available for yet other species of plants in a symbiotic relationship (ie. They help each other out). In a mono-culture, soils can still be quite healthy, but they can have certain particular nutrients mined out. Liebig’s Law of the Minimum, states that a plant’s development is limited by the one essential mineral that is in the relatively shortest supply. Therefore if your mono-crop depletes that single essential mineral/nutrient from the soil, you will no longer be able to grow that same crop again (or it will become progressively unhealthy) until the mineral/nutrient is restored back into the soil; and
  • A poly-culture has the benefit of supplying a larger variety of plant materials over a longer period of time than a mono-culture. This longer harvest time with a poly-culture is suitable to local production and distribution but is not generally adaptable to large scale mechanised agriculture which requires an environment that more closely resembles a factory (ie. Consistency of size, ripening times, and plant spacing). Nature rarely resembles a factory!

People are just like the example of the soil above in that they require a wide variety of nutrients in order to be healthy. You can for example, eat the same food every day, but like the soil example above, sooner or later you will encounter Liebig’s Law of the Minimum and find that you are missing out on a nutrient or mineral which may possibly lead to ill health. The simple answer to this is to eat from a poly-culture!

The only downside to a poly-culture is that you have to practice plant identification, otherwise you won’t know what you are eating! Also, some plants or only parts of those plant can be harmful or toxic, so it is worthwhile taking the time to get to know what the plants look like, what they taste like and what parts can be used and how. This is actually pretty easy to do and eating things that you’ve grown is always fun and enjoyable, but the secret to this skill is practising growing plants and then eating them! Simple, and you get to eat the plants too.

I’ve put a fun video together providing a virtual tour of all of the plants growing in some of my raised vegetable beds here and you can quickly see just how many different plants you can grow in a poly-culture and just how much food you can produce over a space as small as about 40m2. I hope you enjoy the tour and remember that with a world to choose from there is usually some edible plant that can adapt to your location.