We used to weed the ornamental and vegetable garden on our knees by hand or with a hoe.
My grandfather was very concerned with chemical pesticides, including herbicides, because he already knew (this was in the ’60s) that some pesticides are very harmful to the environment and health. And so my brother and I were recruited to weed.
I thought until recently that everybody removed weeds manually as much as possible but it seems that both people and horticulture schools easily grab chemical herbicides to do the job.
This article is intended for private ornamental and vegetable gardens. The control of weeds in agricultural crops is a different problem.
The impact of weed control is also different: of all herbicides, less than 10% is sold in retail, the vast majority is for agricultural use.
By weeding your garden ecologically, you do not so much influence the global environment but you can keep your own garden free of harmful substances and consume your vegetables safely.
Is it really necessary to weed your garden?
A weed is a plant that you do not like or is a vigorous grower which competes with your own plants for light and nutrients.
At the Botanic garden of Meise (Belgium), they recently decided not to fight weed in the park with chemical products anymore. They have hired a company to weed manually. In doing so, they have chosen for a solution where not all weeds can be removed but possibly harmful chemicals are banned.
It is important to remember that weeds are mostly native plants and contribute to biodiversity.
So you have to decide if you want a completely weed-free garden or if you don’t mind weeds appearing here and there between your own plants.
Techniques for ecological weed removal:
Weeding by hand:
The oldest way of removing weeds is manually.
This can be done by sitting on your knees and pulling out weeds by hand.
For some weeds that have a strong or deep root, you will need to use a knife to completely excavate the pen root or rhizome.
There are also special weed puller tools which will cost you 10 USD or less.
Tip: manually weeding works best when the soil is loose, not too dry and not too wet, just moist enough to pull the root out easily.
With a hoe you can easily remove young weeds between crops.
Pull them out of the ground, they die because the roots can not get water anymore.
You can leave the weed which will then act as a fertilizer or pick it up if you prefer your garden to look neat.
Tip: hoe in dry weather, the weeds will quickly die by drying out.
On a patio, footpath or driveway it is often difficult to pull weeds by hand because the roots are quite stuck between the tiles or vowels.
Pouring boiling water on each plant is very effective, the plants die right away.
You can then easily remove the dead plants by hand or with a coarse broom.
Depending on the surface of the area to be treated, you will have to walk back and forth several times with a kettle of boiling water and wait for the water to boil again, but this is not really tiring or difficult.
Plain kitchen vinegar is a rapidly degradable acid that is toxic to all plants.
It is suitable for a patio, footpath or driveway where you can treat each plant individually.
You can use it pure or dilute half with water. Pour it right from the vinegar bottle, from a watering can or sprayer.
It is not selective, so do not use it near your own plants.
Vinegar is especially suitable for the removal of small annual weeds. For larger and stubborn weeds, it is less effective, you will need to remove them in a different way.
Read the article Vinegar in the garden for other vinegar uses in the garden.
Plain kitchen salt (NaCl) or road salt (NaCl or CaCl2) is a very effective but non-selective weed killer.
You can use it in places where you never want any plants to grow (patio, driveway, footpath) but it’s not a good idea to use it among your plants in the garden.
It can be applied in several ways:
- Spread the dry salt onto the surface to be treated
- Dissolve the salt in water (a handful of salt for 5 liters of water eg.) and spread the solution over the surface to be treated
- Dissolve the salt in water and spray directly on the plant leaves while avoiding the soil
This is not my favorite solution because there are several disadvantages: the soil remains unusable for long periods, the grass on the edge of your driveway or patio can die, salt is corrosive to concrete and it is harmful to birds who drink salt water in puddles .
A blowtorch is very effective for patio, driveway and footpath.
Personally, I think this is a little less ecological: you need to buy a blowtorch, this must be manufactured which is polluting and using it consumes energy.
But it works very well, the plants die immediately and you can manually remove them afterwards.
Prevention of seed dispersal:
You should prevent weeds from producing seeds and certainly from spreading them.
Treatment is best applied before seed formation is complete.
In a lawn you do this by mowing the grass before the seed formation takes place. Elsewhere you can prune the flower bud.
Mulching is very effective way to prevent weed emergence by depriving seedlings from light and oxygen.
Inorganic mulch material:
Plastic foil, garden cloth, slate, pebbles, gravel,…
This avoids the emergence of weeds, preserves soil moisture and can be very decorative.
Organic mulch material:
Straw, lawn clippings, paper, algae, wood chips, coconut chips, leaf waste, compost…
Like inorganic mulch material, it avoids the emergence of weeds and keeps the soil moisture but as an added benefit it breaks down and adds the nutrient to the soil.
It also protects some plants against frost in winter.
An organic mulch layer must be regularly replenished or replaced.
Tip: apply a mulch layer in spring.
Organic weed killers:
Some weed killers consist of bacteria or fungi.
These are usually directed to 1 or a few plant species, eg. dandelion.
Synthetic weed killers:
We distinguish low-impact or fast degrading and high impact or slow degrading weed killers.
Low-impact herbicides break down rapidly and are less harmful to the environment and health, but they are less effective than high-impact weed killers.
You will find low-impact herbicides in retail based on:
- Essential plant oils
- Acetic acid (that’s actually vinegar, using simple kitchen vinegar will be a lot cheaper)
- fatty acids
Fighting weeds in your garden is a personal choice: Do you want a very neat and weed-free lawn or garden? Do you mind any unwanted plants to appear? Or don’t you mind a few small plants appearing here and there between your own plants?
Can you and do you want to spend time weeding manually? Do you prefer a handy and beautiful looking mulch layer?
Tell me, how do YOU fight weeds in your garden? I am very curious about this, so please leave me a message.