"Weed control without chemicals" may conjure up unpleasant thoughts of getting down on your hands and knees in the yard on a hot day and pulling out stubborn weeds by hand. But suppressing weed growth without compromising on your organic principles need not be so primitive, so mindless. In the resources to which I provide links below, I discuss a variety of measures to be used to keep plant pests from taking over your flower borders and other garden beds.
These measures should be used in conjunction with each other for optimal effectiveness. Weed removal without resorting to potentially dangerous chemical herbicides can be tough work, and I want you to work smarter, not harder. There is no need to revert to the Stone Age, right?
Laying the Foundation
The first smart idea in a project of weed control without chemicals is to prepare the plot of ground in question. Just as in a construction project, laying a good foundation is of the utmost importance. In this context, by "foundation" I mean the state of the ground where your plants will be growing. Implement these ideas before you plant, so that you will get off to a smooth start in your project.
- Kill weeds through soil solarization: Soil solarization is a preventive, organic method of killing weeds -- before they even sprout. This method is meant for homeowners wishing to start out with a clean slate, re-landscaping a weed-filled patch of land in such a way as to reduce to a minimum the hassle of weed control in the future.
- Lay landscape fabrics: For those in need of soil solarization (see above), installing landscape fabrics can be considered Step #2 in the project of weed control without chemicals. For those with less weedy properties, it is Step #1. I promised you above that weed control without chemicals would not mean going back to the Stone Age, and landscape fabrics are a case in point. These barriers are a hi-tech ally in the battle against weeds. Are they always a good choice? No. Does every gardener love using them? No. But if you are a beginner who adores gardening but hates weeding, you owe it to yourself to learn more about them. I advise experimenting with landscape fabrics to see what works for you (and what doesn't); personally, I find them most effective in shrub beds.
- Use garden mulch: As the final element in a good "foundation" for your bed of annuals, perennials or shrubs, you should apply garden mulch on top of the landscape fabric. Mulch comes in extremely handy not only when fighting weeds, but also unwanted grass. If you read my presentation on how to get rid of grass, you will see that mulch plays a role in several of the methods mentioned.
Many people skip right to mulching in their attempts to control weeds organically, but applying landscape fabric first will lengthen the life of your garden mulch, since it will not break down as quickly if it is not allowed to come into direct contact with the soil.
Pre-Emergent and Post-Emergent Organic Herbicides
"Pre-emergent herbicides" is a fancy way of referring to herbicides that attack annual weedy plants at the source: their seeds. That is, they act to inhibit seed germination in the soil before the plants in question even have a chance to announce themselves to the world above. Corn gluten is an example of a pre-emergent herbicide used for weed control without chemicals. Remember, corn gluten will inhibit the seeds of "good" plants from germinating, too, so do not use it in planting beds where you are starting plants from seed.
By contrast, you apply "post-emergent herbicides" only after the antagonists have appeared on stage. For weed control without chemicals, try vinegar as a weed killer. Even plain old household vinegar is effective if you have only young weeds to deal with in your planting bed (killing older ones requires something stronger, as I detail in my full article on the subject). As with corn gluten, you have to be careful using vinegar as an herbicide, because it is an equal-opportunity killer: being a non-selective herbicide, it not only kills weeds, but also harms landscape plants that are accidentally exposed to it.
In Case You Still End Up Pulling Weeds by Hand
With landscape fabric and mulch in place, the bad news is that, even then, you may still get weeds. But the good news is that those weeds will be very easy to pull out.
Pulling weeds embedded in garden mulch is not nearly as difficult as pulling weeds embedded in soil. Thus with that good "foundation" that I encouraged you to lay, you may not even feel the need to bother with the corn gluten and vinegar discussed above: five minutes of easy pulling here and there should get the job done.
One exception to this may arise: if the integrity of the landscape fabric has been compromised, weeds may strike down roots in the soil beneath, making them difficult to pull out. In this case, water the area in question beforehand. In fact, a general rule of thumb for weeding is that it is easier to yank out weeds from moist soil than from dry soil.
If you are interested in creative approaches to dealing with weeds, you may also wish to read my article on weeds that you can eat.