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how to prevent weeds from growing in vegetable garden

How to prevent weeds from growing in vegetable garden

Keeping weeds out of the walking and growing rows is just as important to the health of your garden as it is the look.

Every time the soil is disturbed, weed seeds can be planted. That includes both hoeing and raking in the garden. Leaving the soil alone is not just less work, but more effective at keeping weeds away.

It is important to realize that eliminating weeds in a garden is a process. But don’t let that scare you. The process is both simple and rewarding, and will only get better with each passing year.

#2 Eliminate Bare Soil – How To Eliminate Weeds

They have obvious benefits to helping your soils vitality, but cover crops also help to form a barrier for blowing seeds to enter and lie in wait.

Our test gardens here at Old World Garden farms are a testament to that fact. Many visitors to the farm are surprised we spend an extremely small portion of our time keeping the 40 x 60 vegetable garden weed free. As in less than 5 minutes a day in the summer!

#3 Mulch, Mulch and More Mulch! – How To Eliminate Weeds

But it simply doesn’t have to be that way. Nor does it mean you have to spend endless hours in your garden dealing with them.

With the walking rows permanently covered with a heavier mulch, the only area of concern for winter are the growing rows. And a cover crop is the perfect solution.

How to prevent weeds from growing in vegetable garden

Herbicides may temporarily reduce early vigor and growth of some vegetable plants, particularly under cool, wet conditions which often occur in early spring. Timing of the herbicide application and seed planting sequence may vary and can determine whether or not a temporary reduction of plant vigor will occur.

Hard-to-kill perennial weeds, such as bermudagrass or nutsedge, may be controlled when the garden plot is fallow (not planted in a crop) with glyphosate (Roundup®) in combination with cultivation.

Buckwheat covercrop.
Joey Williamson, ©2012 HGIC, Clemson Extension

Clear plastic, which increases soil temperature more than black plastic, will not control weeds since sunlight can reach the soil surface. Perennial weeds may be suppressed by black plastic, but plants like yellow nutsedge will push through the material in places.

Crop Competition

Common summer annual grasses include large crabgrass, goosegrass and giant foxtail. Annual grasses are easy to control if appropriate measures are taken early in the growing season but can quickly become a severe problem if not controlled when small. Large crabgrass, for example, will root into the soil at the places where the nodes of the stem contact soil, allowing this plant to quickly cover open ground. The fibrous root system of grasses makes them more difficult to pull out of the ground.

Common summer annual broadleaf weeds include smooth pigweed, common lambsquarters, purslane, galinsoga, common ragweed and tall morningglory. When controlling purslane through hoeing, remove all stems from the garden because purslane can reroot if allowed to remain on the soil surface due to the thick, succulent stem that can survive a period of drought. Galinsoga is often called quickweed, perhaps because it develops quickly and flowers while still a small plant. It seems that most gardens contain purslane, galinsoga or both. Small-seeded broadleaf weeds like pigweed are easier to control than large-seeded broadleaf weeds like morningglory. Larger-seeded weeds can germinate from a greater soil depth and can push through a shallow layer of mulch.

Herbicides are not universally labeled for use on all vegetable crops, because (among other reasons) different crops have differences in tolerance, just as weeds may vary in tolerance.

Chemical Control

The new geotextiles, also called weed barriers, are woven or spun-bonded fabrics containing polypropylene or polyester and may come in black or white. These fabrics are more expensive than black plastic, but they allow water and gases to pass through the fabric. Research generally indicates good control of annual weeds, but annual weeds may be able to germinate above the fabric and send their roots through the fabric. Certain weeds, such as large crabgrass, are able to germinate below these fabrics and push their shoots through holes in the material. Perennial weeds may also push through these fabrics.

In a large garden with widely spaced rows, a rotary tiller will make weed control easy and fast.
Barbara H. Smith, ©2016, HGIC, Clemson Extension

How to prevent weeds from growing in vegetable garden

Step three: Layout your irrigation system and plant. Once your soil has been solarized you can layout your irrigation system. Remember, wherever water is applied, that is where weeds will grow. If you irrigate using a drip system, you can really reduce the number of weeds overall in your garden. Once the irrigation system is in place and you have past the last frost date or planned for cold protection you can plant. For ideas of what to plant when, go to our handy guide at:

Step one: Control existing weeds. If your garden has any weeds, you first need to take care of them prior to doing anything (except planning). You have a couple of options. You may rototill your garden to dig under existing weeds or you can spray out the garden with a non-selective herbicide such as glyphosate (Round-up). You should do this well before you plan to plant. This will only control the weeds that are there now and you will have more weeds germinate as the temperatures begin to warm up and water is applied. You may have to either manually take out any newly germinated weeds or spray just prior to planting. Take care not to bring weed seeds up from lower soil layers by tilling too deeply.

One of the biggest challenges to growing a vegetable garden in a non-raisedbed situation can be the weeds. The can make the garden unsightly, compete with the vegetable plants you really want and make you feel overwhelmed in trying to manage them. Here is your five step plan to a better garden with fewer weeds:

Step four: Mulch. One great tool to reduce weed problem is to use a mulch material over the planting beds