蒲公英要秋天处理

Examples of Herbicides for Dandelions

 

• Organic: Vinegar
• Weed-B-Gon (brand name), with the active ingredient, 2,4-D
• Roundup (brand name), with the active ingredient, glyphosate

It's the acetic acid in vinegar that gives it herbicidal potential. The higher the percentage of acetic acid in the vinegar, the better. Vinegar used for culinary purposes is relatively low (5%) in acetic acid, but you can boil it down to increase its strength prior to the application.

If you use either vinegar or Roundup, apply the herbicide directly onto the leaves of the weeds, since these herbicides are non-selective and would harm your grass. By contrast, Weed-B-Gon is selective (it targets broadleaf weeds) and won't harm grass, making it a popular choice for killing dandelions in the lawn.

When to Apply Herbicides on Dandelions

Early fall is the best time to kill dandelions with herbicides. Dandelions are broadleaf, herbaceous perennials. Since their leaves die back in winter, it is through their roots that the plants live on. In early fall, nutrients are transferred from the leaves down to the roots. This transfer, which continues until the first killing frost, presents you with an opportunity to hit them where it really hurts! Herbicides applied during this time are absorbed by the leaves and passed on to the roots, following the same path down as the nutrients.

For at least 2-3 days prior to applying herbicides, don't mow the lawn. The bigger the surface area of the dandelion leaves, the more effective your application can be. Likewise, following the application of herbicide, wait at least 2-3 days before mowing, to allow time for the herbicide to be transferred to the roots.