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Ag Matters Column: What about those lawn weeds?

Spring is here, officially anyway. With the recent unseasonable snow torms, winter seems to be hanging on with a tenacity unseen in recent years. Although we've enjoyed only fleeting glimpses of spring, we're beginning to get questions on lawn weeds, so this week I'll discuss three common "weeds" that seem to foster concern.

Weeds sometimes get a bad rap. By definition, a weed is simply a plant out of place. For example, a volunteer rose plant growing among your marigolds is technically a weed, since it's out of place. So the definition of "weed" is really a matter of perspective.

Other weeds, such as spotted knapweed, are an invasive, noxious weed and are cause for concern. These weeds often disrupt natural habitats and become invasive, which often crowds out desirable species. Weeds such as these do warrant action.

Here are a few more:

n Dandelion is a perennial that flourishes in sunny areas, especially where the grass is thin. Dandelions, however, are controlled easily with the products containing 2, 4-D, and to a large degree, with cultural methods.

One simple cultural tip is to mow frequently and collect clippings when they begin to go to seed. Reducing the weed seed crop will not guarantee an end to more dandelions, though. Seeds can blow in from elsewhere and remain viable for years in the soil, waiting for a chance to grow. When you have just a few plants present, try digging them out with a dandelion digger or "weed popper."

If you choose to use a herbicide, September is the best time for chemical applications since the plants are transporting carbohydrates from the leaves to the roots for winter storage, resulting in more effective control.

May is the second best time for chemical control, especially when the temperatures are warm and the wind is calm. Moreover, lawn work seems to have greater appeal in May; by September, we are weary of mowing and ready to be done with lawn work.

n Creeping Charlie is a great example of a plant "out of place" since it's actually a quite attractive plant. Its leaves are similar to a geranium, but much smaller in size and you will likely find an abundance of tiny, lavender to blue flowers during the summer. Despite its somewhat attractive appearance, remember, it's a plant out of place -- thus it's a weed.

Also known as ground ivy and creeping jenny, this low-growing perennial weed thrives in moist, shady areas of the lawn and garden, but will invade sunny areas, too, especially if the lawn is thin. If you're a lawn, thin is not good.

Creeping Charlie is more challenging to control. If you catch it early, you may be able to control it by pulling; it actually comes out quite easily. If it becomes thick, you can use a special tool called a dethatching rake -- but eat your Wheaties -- this is most laborious. Hand removal may not eliminate it, but may keep it in check.

The best time for chemical control, as with most perennials, is in the fall. The second best time is spring, when it's in full bloom -- usually, right about now. Two herbicide applications containing 2,4-D and MCPP spaced 10-14 days apart will typically achieve good control. Triclopyr is another option and can be applied at any time during the growing season.

Take special care when spraying, especially in the spring of the year. Nearly all landscape plants are very sensitive to drift from these pesticides, especially trees, garden plants, and flowers. If the spray drift comes in contact with these sensitive plants, it will likely damage them, if not kill them.