Understanding weeds is the key to avoiding chemicals

Understanding weeds and what things encourage them is the first step to controlling the without chemicals. Interestingly, the same is true for pest problems as well.

The first thing to understanding weeds is "What are weeds?" The most common definition being that "A weed is a plant out of place", but things are not as simple as this makes them sound. Weeds (and pests) are opportunists that target areas of disturbance.

From an ecological stand-point, 'disturbance' can be caused by almost anything - frost, drought, cultivation, harvesting - even applications of fertilizer. In short, a disturbance is anything that upsets the balance in the system. It can be prolonged or virtually instantaneous; dramatic or subtle. Disturbance doesn't even need to be bad, but if it opens a niche or imposes stress on your plants, it creates an opportunity for a weed or pest.

To help understand weeds even further, lets also look again at the first definition: "A weed is a plant out of place". Sounds pretty straightforward, right? But lets see what options it gives us. To keep weeds at bay we could:

1. Take the weed out of the 'place' (pull it out or spray it)
2. Put something else in the 'place' (companion plants, cover crops)
3. Remove the 'place' (organize the garden to eliminate a particular niche - usually rather difficult, but still an option).
4. Change the 'place' (soil balancing, mulching)
5. Give the weed a 'place' (once it has a productive use, eg. an edible weed, its not a 'weed' any more.

By better understanding weeds, we can now start thinking about how to control weeds without chemicals. Firstly, there will be no single method, but rather a range of strategies that aim to manage the habitat for the benefit of the plants we want in preference to others. Secondly, we need to realize that this approach will not eliminate weeds - only control them so they are not continually driving us crazy.

The bad news is that there is no miracle formula - it will take experimentation and experience. Of course, I will work hard to give you as much to go on as I can.

The good news is that it should not involve a lot of hard work. I have a friend who managed a 3,000 acre pastoral property in an area heavily infested with Paterson's Curse (Echium plantagineum). By understanding weeds generally, and this one especially, he kept the entire property free of "Patto" simply by keeping a shovel in the back of his car and digging out any plant he saw on his way around.

Truth be told, his success was almost certainly due to contributions from his grazing management, paddock renovation program, soil improvement and planting of shelter-belts throughout the farm, but it sounds more impressive when he says he did it all with nothing but a shovel.

Remember, a successful ecological garden does much of the work for you. And don't forget that everything I have said about weeds also applies to animals that are out of place - Pests.

My Aunt and Uncle run a free-range egg farm and one year there was a plague of Armyworms (actually the caterpillar of a rather ordinary looking moth). They destroyed acres of pasture throughout the region, with many farmers tearing their hair out looking for a solution to the problem. When visiting my Uncle he said "Gee these caterpillars are good, my yolks have never been more yellow. Do you think they will come back every year?"

The next Autumn, the areas damaged by armyworms became infested with Capeweed (Arctotheca calendula). Again the local farmers were totally distressed and cattle were dying from nitrate poisoning everywhere. Again when I visited my Uncle he said "Wow, this capeweed is great, the chooks eat it rots and all. Maybe I should plant some?"

It just goes to show that both pests and weeds are often as much a state of mind as anything. It also shows that understanding weeds is only part of the solution - you also need to be able to get on to a good thing when you see it!

Further Reading

Begin with Soil balance
This is the only essential component of every weed and pest control strategy and should be your first step.

Use companion Plants to take the place away from the weed
You can use companion plants to fill niches in the garden habitat that might otherwise be occupied by weeds.

Use the garden habitat to help in understanding weeds
Understanding weeds also means understanding the garden habitat.

Green manure and cover crops increase biodiversity and help improve the soil
These are two strategies for (among other things) increasing the overall biodiversity of the garden. Careful plant selection will help control pests and weeds.

Crop rotation is a very useful strategy
One of the most useful weed control strategies in the garden.

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