By Yuvraj Khamare, Graduate Research Assistant
in Environmental Horticulture, University of Florida
Photographs courtesy of Yuvraj Khamare
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 affords you the opportunity to more frequently scout the landscape for potential problems.
This is the first step in any pest management program. Learn to identify the weeds common to your area. Scouting your garden and lawn for weeds will enable you to determine which pest plants are present, and plan control methods accordingly. Note the species you see and whether they are broadleaf weeds or grass-like weeds such as crabgrass.
As the saying goes, prevention is better than cure. This adage rings true when it comes to weed control and is the foundation of a non-chemical weed management plan. Start with a healthy baseline. Healthy soil will lead to a healthy garden that outcompetes the weeds.
When purchasing transplants and seeds make sure to buy from a reputable and certified source. When you bring new plants home from the garden center, immediately remove any weeds growing in the pots. Make sure your equipment, containers, soil mixes and fertilizers are clean and free of weed seeds or vegetation.
No matter how fastidious our sanitation and prevention measures, weeds will arrive via the wind, birds, and other animals, including us. Weeding 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 most important to remove weeds before they flower, as some weeds produce tens of thousands of seeds from a single plant. The notoriously prolific lambsquarters (Chenopodium album) produces an astounding 30,000 to 176,000 seeds per plant. Weed seeds can live in the soil for years, just waiting for the right conditions to germinate.
Special attention is needed when dealing with perennial weeds, as they have an extensive root system. With perennial plants, it's important to remove the plant entirely, including 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 weed suppression. Mulch can also provide plants with essential nutrients, helps to retain soil moisture, maintains an even soil temperature and provides an appealing look to your garden. There are different types of mulch available, including pine bark, hardwood chips, sawdust, hulls and shells, gravel, shredded newspaper and many more. 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.
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