Late summer to early fall may not be the showiest time for dandelions, but it’s the best time to eliminate them from your lawn. I usually avoid using toxic lawn chemicals, so I was curious to try the new Ortho Elementals Lawn Weed Killer sample that I received at the recent Garden Writers Association Symposium in Indianapolis. This broadleaf weed killer is made with naturally occurring iron. The active ingredient is iron HEDTA–or hydroxyethylenediaminetriacetic acid, for those of you studying organic chemistry!
The product works by creating iron toxicity at the cellular level. Because the mechanism of iron uptake is different in broadleaf plants such as dandelion from that in monocots such as lawn grass, the weeds die while the grass is unaffected. This naturally occurring chemical is reported to be safe for humans and other animals. Sprayed areas are safe to reenter as soon as the product dries. And further background research shows that iron HEDTA is not persistent, so it is quite friendly to the environment. Additionally, rather than spraying the entire yard, you’re supposed to spray only the dandelions (or other broadleaf weeds you want to eliminate), so much less chemical is used than with conventional weed killers.
The initial results are impressive. I spot sprayed dandelions in my yard this last weekend. In just 72 hours, they looked like the dandelion in the “after” photo below. The true test will be how much regrowth happens. The label indicates that for best results, two applications three to four weeks apart may be necessary. So I expect that the dandelions will regrow from the roots and need another shot of weed killer to wipe them out entirely.
I have to admit that the golden yellow blooms of dandelion can be quite beautiful. But their “pretty” season doesn’t last long. They soon develop fluffy white seed heads that float on the breeze to take root in any available speck of soil.
This year’s crop of dandelions in Des Moines has been prolific! And although the lawn is a lower priority for me than flower beds and the vegetable garden, I just couldn’t leave the dandelions to propagate throughout the neighborhood. Maybe it was was my reputation as a gardener that I was trying to protect. Or maybe it was lingering guilt about “What will the neighbors think?”. Whatever the reason, my husband Patrick and I have assaulted the dandelion scourge with a variety of dandelion removal tools.
I try to garden with few chemicals, so all-out chemical warfare wasn’t a top choice. (I must admit to occasional spot treatment with herbicides, however.) Instead, we use a variety of digging tools to remove the dandelions roots and all. Patrick’s favorite weapon is the Fiskars dandelion digger, pictured on the left side of the photo at right. It has a convenient step bar to aid in puncturing the soil, and a convenient long handled lever that grasps the dandelion root and pulls it out in a single motion. My only objection to it is that sometimes as it pulls out the dandelion root it also removes a large plug of soil, which must be filled back in. I like the long-handled garden trowel at right. The long T-bar handle provides good leverage and results in a minimal amount of bending over. I find that the dandelion root pops out without having to completely remove the soil plug. We also have a traditional forked dandelion digger, which I find just too small for our robust dandelions.
Have you battled dandelions and won? What are your weapons of choice for eliminating the pests? Or perhaps you peacefully co-exist with dandelions, enjoying the greens in salads and using the flowers to make dandelion wine.
That golden bane of perfect green lawns may soon earn a place of prominence in the horticultural world. Sure, there are gardeners who occasionally harvest dandelion greens for salads or make batches of homemade dandelion wine, but the plant remains an all-too-common weed despised by most suburban homeowners.
That may all change if researchers at the Fraunhofer Institute in Germany have any say. They’ve discovered how to make lemonade out of lemons, if you will, by harvesting dandelion latex (that white sticky stuff in dandelion stems) to make rubber. The idea isn’t new. During World War II, the Allies experimented with all sorts of alternatives to latex from rubber trees because plantations in Southeast Asia had fallen under control of the Japanese. But dandelion rubber never took off, partly because dandelion latex polymerizes (sets up) when it hits the air. The German researchers have been able to turn off the enzymes that cause polymerization, and in the process, increase dandelion latex yields by 500 percent. Time magazine called it one of the 50 best inventions of 2009.
Healthy rubber trees still produce a lot more latex than a dandelion plant, but a serious fungus is threatening to wipe out commercial rubber production from trees. The disease has already eliminated widespread rubber tree cultivation in South America, and is threatening to do so in Southeast Asia.
Rubber from natural latex is important in making car tires elastic enough to inflate. If latex from rubber trees becomes unavailable, that from dandelions may take its place. Another bonus of dandelion latex–it appears to be less allergenic than latex from rubber trees.
So, next spring if your neighbors complain about the crop of dandelions in your front yard, just let them know that you’re on the cutting edge of technology, and have started your very own dandelion latex plantation.