Be familiar with your weeds before you determine how to control or remove them.
Cool season weeds are thriving. Here is excellent advice from K-State on how to control one of the weeds we love to hate - field bindweed.
Field bindweed is difficult to control, especially for homeowners, but there are options.
Home Vegetable Gardens: Weed control requires taking the treated portion of the garden out of production for a time.
Solarization - Solarization uses the energy from the sun to produce heat that pasteurizes the soil.
Follow these steps to solarize a garden area:
1. Select the hottest time of year to solarize, usually mid-June to mid-August.
2. Work the soil deeply, and smooth the surface so the clear plastic will make uniform contact with the soil.
3. Water well. Moisture encourages seed to germinate and existing bindweed to grow so plants can be killed by the heat. The water also helps conduct the heat deeper into the soil.
4. Spread clear polyethylene film over the area. Seal the edges and seams with soil to prevent air from circulating under the plastic. One mil film is most effective at creating heat, but is likely to be torn apart by Kansas (and South Dakota!) winds. Film that is 4 mil thick is more likely to last.
5. Leave the plastic in place for 4 to 6 weeks. The longer time is more effective.
6. Remove the plastic after 6 weeks. If you leave it in place longer, it may become brittle from exposure to ultraviolet radiation and be difficult to remove. You can plant the next day.
Glyphosate (gleye-fo-sate)- Glyphosate is sold under a wide variety of names, the most common being
Roundup. Take the garden out of production when treating.
1. Glyphosate is a non-selective herbicide that will kill whatever it hits but is inactivated when it contacts the soil.
2. Glyphosate is most effective when applied to bindweed that is at or beyond full bloom. You can treat earlier but don't skip the late summer to fall application.
3. Do not apply to bindweed that is under moisture stress or not growing well.
Turf: Selective herbicides are available. An herbicide with the trade name of Drive (quinclorac) has, until recently, only been available to commercial applicators. However, there is now Drive packaged for homeowners and is available from Monterey Lawn and Garden (www.montereylawngarden.com). There are also homeowner combination herbicides that contain Drive such as Ortho Weed-B-Gon Max + Crabgrass Control and Bayer All-in-One Lawn Weed and Crabgrass Killer.
Products with Drive work about as well as glyphosate but are selective.
Note that lawns treated with Drive should not use clippings in compost or as mulch as Drive is very stable on grass clippings. We recommend clippings be returned to the lawn anyway but if they are bagged, they should be discarded. Do not apply products with Drive over exposed roots of trees and ornamentals. It would be best to avoid spraying beneath the canopy of any trees to avoid possible damage. If there are plans to convert a section of lawn to a vegetable garden, do not use Drive on that area. Eggplants can be damaged if planted within 12 months of areas treated with Drive, and tomatoes can be damaged if planted within 24 months.
Shrub Beds: Use a spray of glyphosate between plants. Use a shield if spraying near plants to keep spray from contacting green plant material. Remember, glyphosate will hurt your shrubs if it contacts green tissue.
It is possible to control field bindweed by pulling, but you must be extremely persistent. I
remember reading a study from the 1940s that found that bindweed produces enough energy to
start strengthening the roots when it reached the six-leaf stage. So, if pulling, never allow plants
to produce more than six leaves. (Ward Upham)
Weeds of the Great Plains is published by the Nebraska Department of Agriculture.
Albrect Durer's study of weeds in 1503 reveals the same delight in observng nature directly that gardeners today find irresistible. Believe it or not, we had to be taught to do this, so thank you, Renaissance.
Most gardeners have a predictable dialogue with unwanted or unknown plants, usually lumped together and described by most gardeners' most commonly used four-letter word...WEED.
A meaningful dialogue should begin with identification. Once the plant is identified and correctly (not profanely) named, we can learn how it grows, sets seed, becomes a nusiance, or can be managed. But the introduction and identification comes first.
The Weed Science Society of America has links that are very helpful. Clicking on the Weed Science link will bring you to their photo gallery where a large number of recognized weeds or marginally domesticated weeds like Galium, which is also known as sweet woodruff or bedstraw,are listed. The plants are listed alphabetically by common name then the botanical name. The viewer has the opportunity to view photos of the plant flowers, the entire plant or selected parts.
Just for fun, (while the weather is not conducive to gardening) explore all the links in the weed box on the left hand side of the page.
By investing some spare time to become acquainted with the names and photos of weeds this winter, not only can you can call the weeds by their botanical names, you will be a more informed and effective gardener!
DEALING WITH WEEDS
Before we spend a lot of time and energy being upset at the presence of weeds in our yards and gardens, its worthwhile to remember some important things about weeds:
1. Soil wants to be covered. It issues a general invitation to all plants to "take root." Weeds are tough, tenacious, and the ultimate opportunists.
2. Many weed seeds can lay dormant in the soil for years, even decades. Most need access to sunlight to germinate. Thus, when soil is disturbed (in construction, for example) or turned (by plows and tillers, for example) seeds which had hitherto not germinated suddenly are exposed to sunlight and the result is.........vigorously growing weeds.
3. Weeds are not only opportunists, they are also survivors, being well adapted to thrive in poor soil, droughty conditions and other hardship sites. Deep, deep taproots make it very hard to pull some. Others have the annoying habit of breaking off at the soil surface which leaves a vigorous root intact.
4. Nearer to the heart of many gardeners and ecologists is the fact that several weeds - some of which are tansy, Dalmation toadflax (left) and almost all the thistles (right) - are wreaking havoc in our pastures and meadows of native flowers and animal pastures, causing calamatious loss of native plant species.
IS THERE ANYTHING GOOD ABOUT A WEED?
Of course there is, although admittedly it is hard to acknowledge. If weeds are growing in a native or wild community or setting, they contribute several things to the vigorous dynamic of the area:
1. They cover the soil and inhibit erosion or loss from wind.
2. They provide in their foliage and flowers food for myriad animals, birds and insects.
3. Their roots are aerating the soil, providing channels for air and water and providing nutrients for soil microorganisms.
4. When they die and decompose they add humus to the soil.
Most of us are willing to admit those points AND we still want to reduce the weeds in the garden.
Yes, a beautiful flower is a "weed" if it pops up in your lawn. Naturalist John Burroughs argued that "One is tempted to say that the most human plants, after all, are the weeds."
Speculate if you dare. You won't be the first.
(TRYING TO) CONTROL WEEDS
Let's begin by stating the obvious. Look around and educate yourself about the weeds that are already present on your property or are thriving nearby. Are they most active in the coolness of spring or the heat of summer? Do they cast a million seeds or have roots that travel miles underground?
Once you have identified them and their devious habits and hopefully learned the habits of the worst of the bunch, you can make a plan.
Dandelions, (illustration below, left) sow thistle, creeping jenny and other well known weeds basically require near-constant watching and digging up. Others like the thistles, mullein, burdock require a careful plan that takes into account those special times when spraying,(below, right) for example, is effective to kill them.
Not all methods of weed management (Who ever thought we could control a weed?) require the use of toxic chemicals.
Dandelions in a flower or vegetable bed are easily removed early in the spring by digging them up with root intact. Creeping jenny can be managed by vigilance in the garden and removing the plants when they just emerge. Other plants can have their seed heads removed and the plant dug out at a later date.
In all your efforts of weed management, keep in mind that many weeds (to us) are crucial food sources for equally crucial insects, and that the insects are food sources for the birds. Also some plants thought of as weeds (the magnificent milkweed, for example) provide food for the larvae of the Monarch butterfly. Other insects use the flowers as nectar sources. The behavior of bees is terribly impacted by gardens where uneducated spraying happens.
The best efforts at weed management involve the following:
1. Identify the weed and understand how and when it germinates, grows most vigorously and is most apt to set seed.
2. Decide whether removal by digging, manageing by removing seed heads or selective, or appropriate spraying with the correct chemical at the correct time is the best course of action.
3. Always be aware that what may offend the gardener (an unwanted plant = weed) may be food for those creatures (birds and butterflies) that make the garden beautiful.