Vegetable gardening can be a fun rewarding hobby, but there can also be many frustrations. While cultivating our desired plants, we are also creating an environment for pests and weeds. Weeds can be eliminated once they grow or prevented from taking root in the first place by creating an environment that is hostile to them. Are you ready to learn how to prevent weeds in a vegetable garden?
Why do weeds form in a vegetable garden?
Weeds are considered opportunistic plants, so they grow when the conditions are right. While they need many of the same conditions as our garden plants, most weeds can thrive in harsh environments. However, when weed seeds hit the perfect growing conditions of our garden; arable soil, sunlight, water, and warm temperatures, they can really take over.
How to prevent weeds in a vegetable garden
There are many ways to prevent weeds in a vegetable garden. You can choose to tackle them by using natural/organic methods or by using chemicals. Natural methods include mulching, close planting, no-till, or adding cornmeal. Chemical methods such as using pre and or post-emergent sprays are also effective.
Natural methods to prevent weeds
Mulching is a method of preventing weed growth by smothering seeds and seedlings with a layer of organic matter. You can use compost, straw, cut grass, wood chips, landscape fabric, or even newspaper or cardboard. Many people use some combination of these by layering them on top of each other. If you use mulch in between your desired vegetables, it won’t need to be as thick. Just be careful that if you choose straw, you don’t get hay instead; It contains many weed seeds.
• Close Planting or crowding
This is a method of planting so that the mature plants will touch each other when they’re fully grown. Their leaves will shade the soil, keeping weeds from getting the sunlight they need.
• No-Till methods or Hügelkultur
In this method, you use layers of common mulches to create large hills or mounded rows. You start with a thick layer of flat material such as cardboard or newspaper. Then you add dead organic material, such as leaves, wood chips or straw, piling it higher in the middle.
On top of that, you put a layer of compost, again piling it higher in the middle. You can then add your garden soil on top of that. Some people do this in multiple layers creating a sort of garden lasagna. Once you plant your seeds, put straw down on top of the hills or mounds to prevent erosion and airborne seeds from taking root.
Cornmeal gluten with a protein content of 60% or more will stop seeds from growing. It will not work on plants that are already growing and just lying dormant through the winter. But cornmeal WILL work to prevent perennial weeds – like dandelions – from their new seeds from growing. Be careful to only put cornmeal in between the rows where you’re planting vegetables.
Chemical methods to prevent weeds
Herbicides can come in pre-emergent or post-emergent types.
• Pre-emergent herbicides
These sprays work by applying before the weeds emerge. These are usually used in the spring immediately after sowing. Pre-emergence sprays suppress all the weeds in the soil, this gives the sown seeds a chance to get up ahead of the weeds. Examples of these are Dimension and Pre-M.
• Post-emergent herbicides
This type of spray works on growing weeds. They can be either selective, meaning they’ll kill the weeds without killing grass or vegetables, or non-selective, which means they kill everything they come in contact with. Products containing 2,4-D, dicamba, and MCPP are selective, but you should check to make sure that they are selective to allow the types of vegetables that you plan to grow.
Non-selective herbicides such as Round-Up and Quick Pro should be used sparingly and handled with caution.
Using a surfactant
Sometimes a liquid is added to spray mixes called a Surfactant. This acts like glue which makes the spray stay on the leaves of the plant longer by stopping it from evaporating or dripping off.
By adding a surfactant to your spray mix you make the spray more effective. Some chemicals will advise this is added to their spray and some don’t. Surfactants consist mainly of glycol and are inexpensive to use.
Hazards when using chemical methods
• Drift – When using herbicide sprays, there is a risk that the wind will carry it beyond the target area. This can happen with droplets or vapor. Droplet drift is easiest to identify because the affected plants closest to the target area will be more severely affected than those farther away.
• PPE – The personal protective equipment that you’ll need depends on the type and strength of the chemical you use. At a minimum, long-sleeved shirts, pants, rubber boots, goggles, and chemical-resistant gloves are required. For the most potent chemicals, you may also need a wide-brimmed waterproof hat and a respirator.
• Surface Run-Off – Soil & Ground Water Contamination – When applying chemicals to gardens, some will run off with rainwater. It will run across the soil surface and into water collection points such as lakes and rivers. As it moves, it can contaminate the soil and kill plants in its path both on land and in the water.
• Subsurface flow – Water Table Contamination – In addition to running off across the surface of the ground, as rain falls, chemicals can also percolate down through the soil layers. As it does, it can permanently affect the ability of seeds to grow in the future. It can also infiltrate the water table and eventually make its way to lakes and streams.
• Sowing Seeds before a time has lapsed – Some chemical weed repellents are not selective. There may be lag time before it is safe to sow your vegetable seeds. In some cases, you may not be able to plant certain varieties of vegetables at all unless you use a variety that is specifically resistant to that chemical.
How to eliminate well-established weeds
• Pulling by Hand – Pulling weeds by hand is most effective when you do it consistently and when the weeds are young or few and large. This will also give you an opportunity to check on your vegetables to see what might need more tending.
• Torching – This method uses a propane torch on a long wand to literally burn the weeds to a crisp. This is a great method for areas that don’t have plants you want to save, like in between the rows of a vegetable garden. The added bonus of this method is that the torched plant can be used as fertilizer by digging it back under.
• Beheading – Finally, if you don’t have time to pull the entire weed, just pluck off their heads as soon as you can to prevent them from spreading seeds.
While gardening can be fun and rewarding, it also can require regular daily maintenance. Weeding is just one of the many aspects of maintaining a productive vegetable garden. You can prevent weeds before they start through either natural methods or chemical methods, though the chemical methods do have consequences. If you fail to prevent weeds before they grow, there are several methods to get rid of them after they start.