Thursday, June 25, 2009

WEEDS - not the TV show

Ah summer. Full-on blooms, home-grown tomatoes, welcome thundershowers.

And weeds.

My friends, please don't use Roundup. The second most used garden weed killer - once thought to be safer than alternatives - Roundup turns out to be toxic to humans and animals. According to the Journal of Pesticide Reform's Winter 2004 Herbicide Fact Sheet,, we learn that the main ingredient in Roundup, glyphosate, can cause immediate symptoms like eye irritation, burning eyes, blurred vision, skin rashes, burning or itchy skin, nausea, sore throat, asthma and difficulty breathing, headache, lethargy, nose bleeds, and dizziness. It has also been shown to have long-term effects, including genetic damage in laboratory tests with human cells.

Further, a Canadian study of farmers exposed to glyphosate herbicides demonstrated the enhanced toxicity of glyphosate when combined with other the chemicals present in the retail weed control formula. These products have been linked with increased risks of the cancer non-Hodgkin’s lymphoma, miscarriages, and attention deficit disorder. There is also laboratory evidence that glyphosate herbicides can reduce production of sex hormones.

At the bottom of this blog are some links to more detailed information about the problems associated with Roundup and other herbicides formulated with glyphosate. But let us get to the important part of this story, the alternatives.

Among the following alternatives, I confess only to hand-weeding this season, a temporary satisfication for the need to spy my flowers amongst the weeds. Hand-weeding (sigh) too often leads to regrowth when the roots remain partially established. I've successfully hoed before, and I've used black plastic below the mulch. But at this late stage, I'd mess up my mulch to do either, and I've also become much more sensitive to the use of plastic. I'm now using biodegradeable plastic trash bags, and I'm thinking they would eventually betray me as they degraded and let new weeds through. I think boiling water is my next shot. It seems to carry the least long-term effects to the soil.

1. Boiling water. Pour boiling water directly on the weed in question. Take care not to spill the water onto plants you'd like to keep.

2. Vinegar (+ maybe salt + a little dish soap to make it stick). I've read that cider vinegar alone will kill a plant with several applications, while vinegar and salt are a better combo. However, too much salt in your soil will make your soil non-productive, so it depends where you plan to use the salt mixture. Also, remember, vinegar is diluted acetic acid. Acetic acid is corrosive, can be used as a solvent, etc. Over-use of acetic acid can harm your planting beds. If you choose this route, check these instructions by Toni Leland for making a spray guard to guard against wind drift, and ensure you hit only the plant you wish to destroy.

3. Pulling. Yeah yeah. This solution depends on how much space needs weeding, how much patience you have, how many quarters or cookies you have for the neighbor kids, how hard the ground is. You have to carefully get the entire root out, or it will just grow back.

4. Weeding tools: Remember the hoe? I've also heard about some new-fangled weeding tools that might make the job easier. These usually slip down into the ground beneath the plant, hopefully bringing up root with the body. If you have any luck or experience with a particular tool, please report back.

5. Smother. If you're dealing with a patch of garden that nobody will see, you can place cardboard or other darkened material over the offending plants, and they will eventually smother and die.

6. Blow torch. A mini torch will burn the top of plants. This treatment may need to be repeated a few times until the plant suffers enough damage that its roots stop sending new shoots. Remember, though, this is fire, and dangerous. Beware of using it around flamable mulch, or old, dried woody growth. And of course, fire is non-selective and will kill anything accidentally torched.

Garden Prep: I returned to my house in KC well after planting season had commenced, so it's too late for these options. But next year consider these options:

Newspaper or black plastic under your mulch. Too late for this season. This will help with some weeds, but has to be done at the beginning of the planting season, before you get going. You have to pop holes into the plastic to put in plants you do want, and often weeds will find their way through these holes. For a really intense soil treatment, try "lasagna mulching," named because organic matter is layered with with paper or plastic and then another layer of mulch, and then allowed to sit for a few months for the organic matter to decay and improve the soil.

Add organics into the soil. Year after year of fortification with good organic soil amendments and mulch will make your soil all crumbly and much easier to pull weeds out by the roots. Not to mention the boon in harvest. This is where your kitchen composter comes in handy, see myApril 24th blogpost here,

Here are websites for more reading:

No comments:

Post a Comment