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science planting seeds vs pulling weeds

Science planting seeds vs pulling weeds

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 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.

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


Florida betony (Stachys floridana) is a very common landscape weed. Photo by Rebekah D. Wallace, University of Georgia,

A weed is nothing more than a plant out of place. But weeds can compete with vegetable plants for moisture and nutrients, and they can harbor insects.


For easy maintenance, prevent weeds from growing in the first place. Fumigating or solarizing the soil before planting will prevent many weed seeds from germinating. These treatments must begin weeks in advance to be effective, though.

Mulching your bed can be an effective weed preventative. Mulch obstructs light making it difficult for weeds to develop. Common mulch materials include pine-bark, pine-straw, melaleuca, mixed hardwood, and various stone materials. For maximum effectiveness, this material should be applied at least two inches thick in your bed. Mulch should be kept several inches away from plant bases to keep them healthy. You can continue to apply fertilizer and water normally on top of mulch.

Another method of minimizing weeds is to cover the soil with perforated plastic, several sheets of newspaper, or landscape fabrics to create obstacles to their sprouting. You can cover any of these barriers with a layer of organic matter to make them more attractive.

Mechanical Removal (Weeding)

Check your landscape frequently for weeds that need to be pulled or hoed. It’s easier to remove young weeds, because their roots are not as extensive and removing them is less likely to disturb your plants. As your plants get larger, they’ll shade more soil, helping to reduce the number of weeds that germinate and the amount of maintenance needed.

Hand pulling

4H youth volunteering for community service by weeding at a historic farm. UF/IFAS by Tyler Jones.

If only a limited amount of weeds are present in your bed, hand pulling is probably the most effective option. Hand pulling is also one of the most environmentally friendly and cost efficient weed control methods. Make sure you remove the weed’s entire root system when pulling them out of the ground; you can use a small-bladed knife to loosen the roots from the ground.

Shallow cultivation

Shallow cultivation with a hoe or scuffle hoe will "decapitate" and control some weeds if they don’t have root systems that allow them to regenerate.

Some, like seedlings of golden rain tree, are easy enough to pull up and remove by hand. But others, like cat’s claw vine or the invasive elephant ear, usually leave roots, tubers, or other plant parts in the ground that allow the plants to regrow.

Last Resort: Herbicide

In these cases, you’ll either need to keep pulling the plants over time or kill them with an appropriate herbicide. Herbicides are chemicals that are applied to weeds to prevent or kill them. They can be effective if instructions are properly followed and the correct herbicide is used. Timing of herbicide applications is the key to successful herbicide use.

There are many different types; do your research and choose the proper herbicide for your specific weeds. Herbicides containing glyphosate are effective on many weeds, though for woody invasive plants like coral ardisia or Chinese tallow trees, you may need a product containing triclopyr. Always read and follow the product label whenever you use herbicides.

How Do Weeds Affect Plant Growth?

Believe it or not, weeds are plants, but as Penn State Extension puts it, their bad qualities outweigh their good ones. They are not intentionally sown, they grow where they are not wanted and they can be incredibly competitive and hardy. Besides usually being unpleasant-looking, they affect plant growth and can ruin gardens and crops. Out of the 250,000 plant species on the planet, approximately 8,000 of them behave like weeds, which is about 3 percent.

Weeds take much-needed space, nutrients, water and light from other plants. Thanks to their fast-growing nature and hardiness, if you don’t pull weeds promptly, they can take over your whole garden.

How Weeds Cause Problems

Weeds produce prolific numbers of seeds and grow and establish themselves quickly, spreading and growing in places that plants cannot survive. Their buried seeds can survive year after year, and adult weeds can have deep roots that are hard to pull out. Many of them look like plants, and this mimicking ability also contributes to their survival success. After all, if you can’t recognize that a particular plant in your garden is a weed, you’re much less likely to pull it out.

One of the most significant issues with weeds and crops is that they reduce yields because they compete for light, space, water and soil nutrients. They also provide shelter for insects and act as hosts for crop diseases. Weeds produce chemical substances that can be toxic to crop plants, humans and animals. Sources estimate that United States farmers spend about $3.6 billion every year on chemical weed control along with another $2.6 billion on other methods.

Weeds Are Bad for Plants

Realty Landscaping bring this issue home by explaining how weeds damage plants in lawns and gardens. First, they take needed space away from plants, preventing the desirable ones from reaching their full potential. If you don’t weed your garden, these unwelcome guests can take it over in a matter of days or weeks before going after other available space. Before you know it, your entire garden could be weeds instead of the plants you wanted.

Like plants, weeds also need light, water and nutrients to survive. They can steal potassium, nitrogen and other nutrients from the soil, making your plants more likely to succumb to insect infestations and diseases. Weeds can also cause abnormal color and growth in tomatoes, blueberries, squash and other fruits and vegetables. Some weeds are also parasitic and attach to the roots and stems of healthy plants, draining their nutrients.

Weed Prevention 101

To prevent weeds from moving into your garden, try to cover any bare soil. Spreading mulch is helpful and can also prevent soil erosion. Do not till your garden, as this moves weed seeds on the surface down into the soil. To remove weeds, Fine Gardening suggests taking a sharp knife with a narrow blade and slicing through the roots instead. Cutting off their food sources is better than stirring up the seeds.

Chopping off the heads of annual weeds (deadheading) can reduce reseeding and limit their spread but is not a permanent solution. When removing weeds, abide by the “pull when wet, hoe when dry” theory. Weeds are easiest to pull out when the ground is wet, so wear a pair of gloves and get to work. Slice the weeds below the soil line with a sharp-edge hoe or an old steak knife if it is dry.

For a natural weed killer, Smith’s Pest Management recommends 1 gallon of white vinegar, 1 tablespoon of liquid dish soap and 1 cup of salt. Mix the ingredients and pour them into a spray bottle. Spray the solution onto the weeds at the sunniest, warmest time of day. The weeds should be brown and withered in a few hours. Borax is also effective; add 1 cup into 2 gallons of water, spray the weeds at the roots and wait for those invaders to die.