Taking the example of the forest in gardening is an idea that can be found almost everywhere (me included).
Indeed, the mechanisms at play in a forest can in many ways show us the way to envision a healthy and productive vegetable garden with enthusiasm and confidence.
But is this example of the forest really suitable for a vegetable garden?
To what extent can we reasonably and usefully draw inspiration from it?
Let’s try to look at things objectively.
To do this, let’s look at 2 gardening techniques (approaches) that are directly inspired by the forest:
- ground cover
- woodland gardens
The example of the forest as ground cover in a permaculture garden
A protective and nurturing ground cover
Yes, a forest does not need external fertilization; materials (dead leaves, branches), as well as animal waste (yes…it’s not just plant matter) are enough to feed the trees and other plants that grow there.
It is therefore easy to understand that this natural ground cover is beneficial and even essential for the development of the plants that make up a forest.
And this pattern can be easily reproduced in a garden, for the greater good of our crops.
But let’s not forget that the process that takes place in a forest has been going on for hundreds, even thousands of years… which is rarely the case with a vegetable garden.
And above all, if we want to take the forest as an example in our gardens, we must nevertheless be consistent, by looking at what really happens in a forest area…
But that is far from the case, as we will now see.
Really permanent ground cover?
A simple question now needs to be asked: Is this cover in a forest really permanent, as many permaculturists claim?
Not really… take a walk in the spring in a forest; and you will find that in many areas the dead leaves have practically, if not completely gone… they have been consumed by the soil… which is in fact often (almost) bare…
And yet, as these same permaculturists rightly point out, the forest thrives…
Which ultimately discredits this idea that the soil should alone never being naked.
Very thick ground cover?
“Lay at least 30 or 40 cm of mulch! †
This is the buzzword in permaculture…
But here too it is enough to take a walk in the forest, for example at the end of autumn, to note that the thickness of the materials (dead leaves and branches) that have fallen to the ground is not so important… And, we said above, in the spring this thickness is even less.
Therefore, if we want to take the example of the forest, the thickness of the ground cover should be much more reasonable…
And if we know the problems associated with spring ground cover (prevention of soil warming, destruction of young seedlings by snails, small rodents or certain ground pests that also appreciate good coverage), may we also ask?
I think compromises have to be made…
Also in the spring, one or two weeks before setting up crops, I choose to remove the mulch (which has played its protective and nourishing role since last spring) to let the sun warm the soil (and if necessary to loosen it up a bit with my Campagnole).
So the soil remains bare, for a few days or short weeks… and the crops will eventually come off all the better, without affecting the life of the soil (or in a very small way).
Once the cultures are in place, I practice what I’ve called “progressive mulching”:
I admit, I am also taking some liberties here with regard to the teachings of the forest…
For example, the thickness of the cover in summer is greater than that of a forest. But the circumstances are also not quite the same: in a forest, the foliage of the trees protects the ground from the sun’s rays… the cover placed in my vegetable garden somehow compensates for that.
“But Gilles… If you want to protect your crops from the sun’s rays, plant a garden forest! †
Okay… here we come.
The example of the forest and the forest gardens
Starting from this notion of the example of the forest in gardening, the fashion for garden forests is developing strongly.
Sure, this model is tempting, and often very productive and convincing… for a few years, but when the trees really start to develop, it’s often different.
Vegetables are not forest plants…
In the forest, at the foot of the trees, we mainly find young tree shoots and shrubbery.
But in reality, only a few low plants grow… species that are also perfectly adapted to this special environment.
And in addition, for most of them, in somewhat open areas develop…
But that’s not the case with vegetables… they are fragile plants, improved and selected by humans over the centuries… and that need loosened soil in order to develop properly.
However, is forest land loose? Can you dig it by hand easily? Usually not really.
If you sow a tomato or lettuce seed directly on this loose soil, will it grow? I highly doubt it.
And if it manages to get going, isn’t the young seedling quickly devoured by an animal? It’s more than likely…
So we see that, as far as vegetable crops are concerned, the example of the forest is not really suitable…
Taking it as an absolute reference for a vegetable garden is therefore simply not appropriate!
Root development of trees becomes a problem!
When a tree is still young, the roots are still small.
But when that same tree grows, its roots grow with it.
Roughly speaking, a tree’s root system is believed to colonize approximately the surface beneath its branches.
However, these roots will absorb a large part of the nutrients present in the soil…
They will also very simply, in many cases, prevent the root development of our crops…
The immediate vicinity of trees is therefore not suitable for vegetable crops.
So some will not fail to say to me that we can plant “nitrogen-fixing” trees, which are supposed to enrich our garden…
Yes, certain types of trees or shrubs (e.g. black alder, speckled alder, locusts, sea buckthorn, etc.) will indeed suck up the soil, or even take nitrogen into the soil.atmosphere… but it is very minimal… and above all, this nitrogen will not are returned to the current crops … only when the leaves of the tree fall to the ground and decay will this nitrogen be available … that is, in winter (the time they decompose) … so there will undoubtedly remain a little left for next spring’s harvest… but does this compensate for the amounts the tree absorbs into the soil? … make me doubt.
Shade is also a problem…
In the early years of the development of a garden forest, the shade created by young trees, if insignificant, is not such a big problem.
But the more the years pass, the more important this shade becomes… to eventually cover the whole garden.
However, some crops (especially fruit vegetables) have a hard time growing well and producing well, especially in the shade…
For example, I am increasingly getting questions such as: “I have a beautiful woodland garden… I don’t understand… my tomato plants haven’t been producing anything for 2 or 3 years now…”. And when a photo is attached to the post, I immediately understand why… the tomato plants are directly above a beautiful fifteen-year-old cherry tree… so completely shaded and with roots in direct competition with those of the cherry tree.. who do you think wins?
The ground cover must be well thought out and adapted to the different situations…
Thoughts must be made, compromises made depending on the soil, climate and other parameters specific to each environment.
Making a dogma of it is in my opinion (which only concerns me) pure stupidity.
As for trees, let’s be clear: they belong in a garden.
In particular, they will provide useful organic matter and make a concrete and broad contribution to the conservation of biodiversity… not to mention their undeniable ornamental value.
But the place of a large tree (always think of its future development… an oak is not a hazel…) is minimally removed from crops in my opinion.
The shrubs will be easier to grow in the vegetable garden itself… but by being vigilant there, as well as to future root and shade development.
In short, as always, an objective analysis of things is much preferable to blind obedience to any dogma.
There are things to be learned from the observation of the processes at play in the forest… but let’s not turn it around!
Your comments, reflections and sharing of experiences on this subject are welcome… even if they disagree with my view of things (we are here to move forward together, not to be stuck with certainties).
To your keyboards then!