Series: Free Organic Gardening Course
- What Is Soil Made Of And How Does Soil Form?
- Home Soil Testing – No Need For A Soil Test Kit
- How To Prepare Soil For A Garden – 2 Different Ways
- Soil Sample Testing – How To Take A Soil Sample
- Natural Organic Fertilizers – How To Choose For Your Garden
- Organic Garden Pest Control – Without Toxins
- Organic Weed Control – Kill Weeds Naturally And Forever
- Organic Composting 101 – Making Compost Better
- Worm Bin Composting – How To Build A Worm Compost Bin
- Homemade Fertilizer – 2 Great Easy-To-Make Fertilizers
- Cover Crops For Gardens – Build Soil And Control Pests
- Soil Inoculant For Plant Nutrition (And Fewer Pests)
- Permaculture Principles – A Few Tips For Your Garden
- How To Make Your Own Garden Inoculant For Less Than $1
- How To Plan A Landscape Design – 6 Steps To A Good Garden
- Seedbed Preparation, Sowing Seed And Planting Vegetables
- Want To Grow Organic Food? Here Are Some Tips
- Forest Gardening – How To Grow A Food Forest
For many of us, organic weed control means many hours crouched in the garden pulling weeds.
And after a while, it’s easy for an organic gardener to begin to think of the buttercups or bindweed as the enemy.
So I’ll give some tips on how to kill weeds naturally in this article.
But at the same time, many of us may have an inkling that weeds aren’t simply the enemy, that it’s more complicated than that.
After all, many weeds are edible or have medicinal properties.
The difference comes down to this: weeds are soil healers…
Benefits Of Weeds
Dandelions are highly beneficial weeds which often thrive in soils with low calcium//humus.
Many of these annoying plants we end up plucking from our garden beds are pioneer plants.
That means it’s their ecological job to restore imbalanced soil to a state of health.
This is why many weeds either host nitrogen-fixing bacteria – for example clover, trefoil, and vetch.
Or accumulate particular mineral nutrients – like thistles, dandelions, or plantain.
They share these nutrients and organic matter with the soil when they die, feeding the soil bacteria and nourishing the soil food web.
They also support healthy soil ecology by exuding nutrients through their roots while they’re alive, as their determined taproots break up compacted soil and improve tilth.
Weeds are generous givers!
What Weeds Tell You About Your Soil
Just as healthy plants don’t attract insect predators, well-balanced soils are much less likely to grow weeds.
We can even make some reasonable guesses about what’s going on with our soil, just by seeing which weeds are showing up.
For example, groups of grassy weeds tend to indicate low available calcium in the soil, while broadleaf weeds suggest a lack of phosphate relative to potash.
This doesn’t mean we should run off and apply single-nutrient organic fertilizers willy-nilly just based on the presence of a few dandelions, but weeds can add color to the picture of our overall soil health, and can help confirm soil test results.
Still, in the meantime, I know you want to get rid of them, and the good news is there are many organic weed control methods other than pulling them by hand…
Organic Weed Control In 6 Steps
Clover supposedly hangs out in fairly nutritious soils, although I sometimes wonder if it’s there to increase nitrogen/humus. I actually recommend seeding it.
We can start first by doing what we can to avoid bringing them into the garden through low quality seed mixes or improperly composted manure.
It may seem surprising that seeds could germinate even after going all the way through a horse’s digestive tract, but it’s true! The compost needs to get hot to kill these persistent little packets of life.
The second step is to balance the soil nutrients. Our plants want balanced soils, while weeds thrive on imbalanced soils.
I’ve been amazed to see insect predators leave plants and move over to the weeds as soil nutrients become more balanced.
Balancing the soil is especially important for organic weed control in lawns where we can’t use a mulch to smother out the weeds.
Which leads me to the third tip for how to kill weeds naturally – you’ll want to keep a nice thick layer of mulch on the soil all the time, once your seedlings have grown enough to reach light above the mulch.
Mulching is helpful for any number of reasons, not just for weed suppression, but this would be a good enough reason on its own. If you have a large home garden, mulching can save you dozens or even hundreds of hours over the course of a year.
The forth organic weed control tip is to crowd weeds out by planting densely, and planting polycultures of different plants that will keep the soil shaded.
There will pretty much always be something that grows on bare soil, so if you can keep the soil covered in multiple levels of desirable plants, the weeds won’t be as big of a deal.
The fifth organic weed killer, for those weeds that do make it through, is using a sharp hoe and cutting them off just below the soil surface.
It’s less work than hand-pulling, and can be very effective, especially for annual weeds. Even for perennials, it will weaken them over time.
The sixth step is to apply boiling water (only good for small areas obviously) or spray them with household vinegar (5% – very safe but not so useful for perennials or other tough weeds) or horticultural vinegar (10-30% – can burn your skin pretty bad, but works better).
How To Kill Weeds Naturally
Take a longer view.
Soil is full of seeds and bits of root, waiting weeks, years, even decades for the right conditions to germinate.
When that moment arrives and the soil lies bare, these dormant seeds will spring into action like liability lawyers in a trauma ward.
So there’s really very little point trying to eliminate weed seeds and roots from our soil.
Instead, we can keep our soil healthy and well covered with plants and mulch, so weeds can take a nice long holiday from their job as healers of imbalanced soil.