Combination products containing fertilizer and herbicide, better known as weed-n-feed, have been officially banned in Canada. Many provinces already had some legislation on weed-n-feed or cosmetic herbicides but the decision by Health Canada in 2010 has brought a ban on sale and use of the once popular combination product. Now, homeowners are complaining mightily about the abundance of dandelions and the uselessness of other products.
Is Canada doomed to be covered in dandelions, or is it just hysteria?
What is Weed-n-Feed?
Weed-n-feed is a combination of fertilizer and broadleaf herbicide that is usually applied mid-season as a way to knock down weeds and feed the grass in one easy application. The fertilizer ratio can vary but most popular brands use a high nitrogen water soluble fertilizer which encourages top growth and does nothing to the overall health and vigor of the plant. It's just a bridge to the next product. In fact, excessive nitrogen can lead to grub infestations and disease conditions.
The weed portion of weed-n-feed is where the trouble starts. The herbicide is a powdered form of popular broadleaf herbicides containing 2,4-D, mecoprop, and dicamba. The 2,4-D, mecoprop, dicamba match up is popular for its lethal action on broadleaf weeds while leaving lawn grass unharmed. Granular weed-n-feed works by sticking onto the surface of the weeds so conditions must be right for the product to work.
The lawn should be wet so as to allow the herbicide dust to stick to the leaves. It is also important that rain is not forecast so as to not wash the product off the leaf before it has done its job. These necessary conditions can make applying weed-n-feed properly and effectively quite difficult, which leads to misuse.
Why is Weed-n-Feed Banned?
The legislation concerning using weed-n-feed in Canada side-steps the real controversial aspects of using chemical herbicides -- mainly the health concerns of long-term, repeated exposures -- and goes for a more agronomic approach. While there are real health concerns with using chemical herbicides, especially for children, pets, pregnant mothers, and the elderly, weed-n-feed simply does not make sense as a lawn care product.
First, applying herbicide as a blanket application is not necessary. Weed-n-feed products spread herbicide to the far reaches of the lawn whether there are weeds growing there or not. Practices like this are out of touch with Integrated Pest Management (IPM) and other, more sensible approaches to lawn care. Using herbicide where none is needed is excessive and not environmentally sound.
Another problem with combining the two products is that fertilizing the lawn and killing weeds on the lawn are two separate events agronomically speaking and should not be combined. Fertilizing the lawn should be done in accordance with your chosen lawn care regimen while eliminating weeds is it's own cultural practice and can be done safer and more effectively by spot spraying throughout the season.
Although the Canadian government manages to steer clear of the health effects of weed-n-feed, the crackdown of other forms of pesticides by various municipalities is a clear indication that the long-term effects of these products are either dangerous or have the potential to be and in accordance with the precautionary principle, they have no place on our sports fields, playgrounds, and home lawns.
So How Do I Control Dandelions?
In some areas, any cosmetic use of herbicides has been outlawed, not just weed-n-feed, and even spot spraying weeds is not a viable alternative. A simple IPM program will help as will a proper lawn care regimen. In any case, a strong argument could be made for looking into organic lawn care. Organic weed control takes a more holistic approach to weeds and sees their presence as a sign of other underlying problems.
Many weeds will invade when grass is stressed or thin/bare turf is present. An aggressive overseeding program will help, as will mowing the lawn at heights of 3 inches or more. Dandelions tend to favor soils low in calcium, so a soil test and subsequent calcium applications may be a way to reduce their numbers. Ultimately, providing the optimum conditions for growing grass is the best way to control weeds.