BY DEFINITION, A WEED IS A WILD PLANT growing in an undesirable location, in competition with cultivated plants. There are numerous strategies to fight weeds, including both chemical herbicides and non-chemical measures. There has been a growing awareness of the negative and devastating effects of chemical herbicides on the environment as well as on the health of people and animals. This has piqued many gardeners’ interest in chemical-free weed management.
Without chemical herbicide in your arsenal, weed control can be a real challenge. This worthy battle requires patience, persistence and planning to be successful. There are many benefits to using a non-chemical approach, including lower risk of damage to cultivated plants and decreased costs. Chemical-free means safer for you and the environment, and offers you the opportunity to more frequently scout the landscape for potential problems.
Scouting is the first step in any pest management program. Learn to identify the weeds common to your area. Scouting fields for weeds will enable you to determine which pest plants are present, and plan control methods accordingly. It can be done simply by walking and recording the species encountered. Note the species you see and whether they are broadleaf weeds or grass-like weeds such as crabgrass.
Cultural control - Sanitation/Prevention/Exclusion
As the saying goes, prevention is better than cure. This adage rings true when it comes to weed control. This is the foundation of a non-chemical weed management plan. Start with a healthy baseline, by ensuring that your soil and other substrates are healthy and weed-free, which will lead to a healthy lawn that outcompetes the weeds.
When purchasing liners and seeds, make sure to buy from a reputable and certified source. Eliminate possible seed sources, and take time to walk through the property on a regular basis to identify a weed and eliminate it before it seeds. This can include your walkway or neighboring property. Sanitation also means making sure the equipment, containers, substrates and fertilizers used are clean and free of weed seeds and vegetation.
No matter how fastidious our sanitation and prevention measures, weeds will be eventually introduced through the wind, birds and other animals — including us. This is seen as hard labor by a lot of people, but with a good weed management plan and systematic weed pulling, this gets easier as the weed infestation eventually decreases.
It is best to pull weeds while they are small. It is important to remove weeds before they flower, as some weeds produce tens of thousands of seeds from a single plant. A prime example is the notoriously prolific lambsquarter, which seeds an astounding 30,000 to 176,000 seeds per plant.
Special attention is needed when dealing with perennials, as they have an extensive root system. With perennial plants, it’s important to remove the plant entirely, grabbing from the base and removing the entire root, to ensure the plant does not grow back.
Mulch is applied to the soil surface to create a barrier that prevents weed seed germination and suppresses the growth of new weeds. There are different types of mulch available, including pine bark, hardwood chips, sawdust, hulls and shells, gravel, shredded newspaper and many more. Mulch also can provide plants with essential nutrients, help retain soil moisture, and help maintain an even soil temperature. Used artfully, it also provides an appealing look to your garden. To effectively suppress weeds, the depth of mulch application should be about 2 to 3 inches.
There are herbicides you can make using household ingredients. While some can be effective, others are not. Some, like salt or borax, can damage the soil so that nothing will grow, or can be toxic to humans or animals. They must be used carefully, as you would synthetic herbicides.
Some homemade herbicides include household vinegar, corn gluten, boiling water, rubbing alcohol diluted with water, and a strong soap mixture. Some plant-based oils like clove, eugenol, lemongrass, citrus, thyme and oregano are also known to kill weeds.
These herbicides do not discriminate, so watch your application carefully, and be mindful not to get them on your desired plants as they will harm them, too.
Practicing these techniques will help to reduce weed pressure steadily year after year. A well-rounded weed management approach that combines several of these techniques is most effective. The non-chemical approach requires persistence and patience, and in cultivating those skills, we become responsible stewards of the land.
Got a question about weed management we didn't answer here? Have you tried managing weeds without chemicals and want to share your story? We'd love to continue the conversation.