One Gardener’s Flower Is Another Gardener’s Weed

On a cool and refreshing spring morning, a homeowner walks out to his pristine bluegrass lawn and marvels at the light covering of dew glistening on each and every gorgeous blue-green blade of grass. He walks about, leaving dew-marked footprints behind.Then, suddenly, in horror, he stops dead in his tracks. The adrenalin begins to pump through his veins—for there, between his feet, is a clump of leaves that can belong to none other than the dreaded wood violet (or common violet). This is a weed that can be hard to control, and in most cases the sighting of one plant in the lawn means there may be many, many more to follow.

On a cool and refreshing spring morning, a homeowner walks out to her cool season lawn and marvels at the light covering of dew glistening on each and every gorgeous blade of grass. She walks about, leaving dew-marked footprints behind.

Then, suddenly, in a fit of joy, she grins, then the grin broadens into a smile, and her whole body relaxes—for there, between her feet, is a clump of leaves from a wonderful wildflower, the wood violet. She marvels at nature’s mysterious ways and hopes the violet will spread and liven up her yard.

The message from these two incidents is simple: One man’s weed is another woman’s wildflower.

Which raises the question: What is a weed? For most of us, the answer is simple—a weed is a plant growing in a place where we don’t want it. Now, getting rid of it or preventing it from ever showing up? Well, that’s a much more complex tale, as I’m sure you know.

Weeds are everywhere and, as any gardener can tell you from last year, they thrive with or without water. Any patch of bare ground or space where turf has thinned out will become quickly populated with some weedy plants.

The fact is that huge quantities of weed seed are found in all soils from the surface down to a depth of 6 to 7 inches. At any given time, about one weed seed is ready to germinate and start growth for each square inch of soil. Worse yet, many types of weed seeds can stay viable but dormant in the soil for many, many years. They sit and wait until you pull up another weed or otherwise disturb the soil, thus bringing the quiescent seed to the surface and giving it that critical germinating ingredient—light.

Weed seeds get into the soil by a variety of means. Some spread from parent plants that may have become established in part of the lawn or garden. Some blow in or are brought in from outside by birds and other animals that cross the property. Some wash in from other areas as water drains across the landscape.

Very few weed seeds come in with lawn grass seed, as only the cheapest bargain blends and mixtures are weed seed contaminated, and even these are relatively clean compared with what you can find in the soil. When you’re buying lawn grass seed, read the label to be certain of this, as weed content, by percentage, must be listed. Also consider that a tiny amount or percentage of weed seed in a turf grass box or bag can mean problems in no time.

Once the weed seed is in the lawn itself, it works its way into the soil through the activity of worms, insects, weather and mechanical means caused by us. Some seed is carried into the soil as water moves down through cracks and other channels. There, the seed waits for conditions to become right for germination and growth, and because of the large reservoir of weed seed in the soil, weeds can be a constant threat. At any time lawn grasses become weakened, so that vigor is lost, there is a potential opening for some weed.

This summer, if you have an armyworm or grub invasion and the turf is thinned out … the weeds are just sitting there itching to see the light and germinate. As long as a healthy grass plant is taking up space, weeds cannot get a start. Let that grass plant become diseased or weakened by insects, malnourishment, erosion or wear, and the weed seedling has an advantage. Also, lawn grasses that are weakened by high temperature and drought in the summer and cold-induced dormancy in the winter are left vulnerable to weed encroachment.

As far as lawns are concerned, the best defense against weeds is a dense and healthy lawn. And, no, this does not mean you need to pour tons of fertilizer on your lawn and use hundreds of gallons or pounds of herbicides—but that’s another column.

As for weeds in your flower beds, tree rings and vegetable gardens? Here, the key word is “mulch,” which is also another column.

Most weeds become established in later winter and early spring, and again in late summer and early autumn, when lawn grasses are characteristically less dense and less competitive. This is why weed killers used in the fall and in the spring are effective in preventing the further spread of troublesome weeds.

When you see a weedy lawn, what does it tell you? Well, there are several possibilities.

It may mean that the folks who have that lawn don’t care and have just let it become run down. On the other hand, it may mean that the lawn is receiving so much tender, loving care that the lawn grasses are weakened by over-watering, too much fertilizer and excessive use of pesticides. It may mean that the wrong turf grasses are in the lawn; poorly adapted lawn grasses are usually prone to weed infestations. It may mean that the right lawn grasses are in the lawn, but varieties that are insect and disease susceptible were planted.

It may mean that the lawn is being mowed so short that the grasses can’t survive. It may mean that the lawn is overused—so much play and traffic that the soil is compacted so only weeds can grow. It may mean that the soil is unfavorable for growth of lawn grasses, as in too sandy. It may mean that there is too much shade, or that the wrong grass was used for the shady area. Finally, it may have to do with your neighbor’s lawn, as that can be a weed reservoir.

These eight conditions are responsible for most weedy lawns. It’s evident that there are at least eight corrective measures necessary before the use of weed killers is even considered. Why kill weeds when they’re only going to return because the turf is thin?

Next week: Your self-weeding lawn and weed-free gardens. In the meantime, check out this link for help in knowing what weeds you have: http://bit.ly/2pjH4RY.

Keep growing!