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How To Kill Weeds and Keep Trees and Shrubs Safe

You can either use natural or chemical methods to kill weeds in your garden.

The safety of your trees and shrubs will depend on how you apply these methods.

With careful application, the safety of your trees and shrubs is guaranteed.

The chemical method employs the use of herbicides.

In contrast, the natural method applies methods like uprooting, mulching, shading, and tilling to kill or provide conditions unfavorable for weed growth.

tree weeds feature

Natural and Physical Methods of Killing Weeds

No matter how careful you maintain your garden, some annoying weeds will pop up.

Whenever you spot weeds, it is essential to try natural, environmentally friendly methods to kill and control them; do not always go for a weed killer.

Suppose you notice some weeds sprouting in your flower bed or lawn; try uprooting or digging them out.

These can be affordable, environmentally friendly but yet effective methods of killing weeds.

Furthermore, as long as they are done carefully, your trees and shrubs will be safe.

Some of the natural methods of killing weeds include:


Organic Mulching

Mulch is any material that can cover and smother weeds.

Apart from killing and preventing weed growth, mulching will also conserve moisture by preventing excessive evaporation; therefore, you don’t need to water your trees and shrubs too frequently.

Organic mulches break down and release nutrients that make your farm more fertile.

Some of the materials you can use as mulch materials are:

  • Dry grass
  • Dry leaves
  • Hay
  • Pine bark straw
Principles of Safe Organic Mulching
  • Ensure you do not put excess mulch next to tree trunks or plant stalks, as it can lead to tree diseases or decay.
  • Avoid excessive mulch as it can reduce oxygen concentration. The mulch layer should not exceed three inches.
  • If you choose to use organic mulch, ensure that it is not contaminated with weed seeds, rhizomes, and tubers.

Inorganic Mulching

Inorganic mulching uses synthetic materials that can be grouped into black plastics and geotextiles.

Black plastic is primarily used to control annual weeds.

When using black plastics, ensure the soil has adequate moisture before you apply.

Furthermore, you should frequently check the soil under the plastic to ensure that it has adequate moisture.

Stabbing Method

Stabbing kills weeds by destroying their food storage structures, which leads to their subsequent starvation and death.

Weed stabbing is done by pushing a knife or a pruning saw as far as possible to ensure the taproot of the weed is severed.

Shading or Minimizing Light Exposure

All plants require adequate sunlight to survive; thus, you can minimize light to facilitate natural weed death.

Shading is a natural weed suppression method that kills existing weeds and prevents the growth of new weeds.

Tighten up the spacing between your shrubs and trees to cut out any weeds.

To naturally keep off weeds, add trees or shrubs that spread widely close to the ground.

Physical Control

Since large weeds will remove excess moisture and nutrients from the soil, early weed removal is essential.

pulling up weeds

Use a hand pulling for small gardens and raised beds.

Uprooting is very effective for killing herbaceous and floating weeds.

If you are uncomfortable with uprooting weeds with your hands, you can use weed wrenches, especially when uprooting weeds that are too big to pull manually.

Pulling is cheap and will cause minimal damage to your desired trees and shrubs.

Do it slowly to avoid disrupting the soil.

Hand pulling is usually applied on small farms and is easy to plan and implement; all you need is to pull out the weed with minimal soil disturbance.

On the other hand, tools are used when you require some good grip or mechanical force is required on the weed.

A hoe will work best in extensive gardens where the number of weeds is overwhelming.

Hoeing should be done carefully and slowly.

Furthermore, hoeing should be shallow to prevent damaging roots near the ground.

You can also use manually powered rotary cultivators on long rows and pathways as long as the soil has an appropriate amount of moisture.

Avoid excessive disturbance of the soil during cultivation as it is likely to bring more viable weed seeds to the ground for germination.

Cultivation should be followed by mulching to reduce future weed growth.

Chemical Weed Control

Chemical weed control uses chemicals called herbicides to kill weeds or inhibit their growth.

Chemical weed control is considered a more effective and time-saving method of weed control.

Unfortunately, not all chemicals are formulated to only harm weeds.

The majority of the chemicals are non-selective.

There are various ways you can apply chemicals on weeds.

tree weed control

Soil Surface Application

In this method, the applied weed killer forms a layer on the soil surface.

Since most of these chemicals have low solubility, they do not leach into the soil, thus killing existing small weeds.

Soil Incorporation

In the soil incorporation method, you apply the herbicide on the soil surface, after which it is incorporated into the soil by either tillage or by irrigation.

Subsurface Application

It is primarily used to control perennial weeds by injecting weed killers into the lower areas of the soil at various points.

Spot Application

In spot application, the chemical is applied or poured only on the weed areas.

This method, however, leaves weed-free spaces untreated, thus minimizing the amount of herbicide required.

Direct Application

In direct application, the chemical is applied directly to the weeds growing between plant rows.

Ensure it is done carefully to avoid spraying the herbicide on your desired plants.

Safe Chemical Weed Control

Many weed killers have an active ingredient called glyphosate, which doesn’t differentiate weeds from trees and shrubs.

Glyphosate kills most plants it comes into contact with.

Drifting chemicals onto your desired plants is called spray drift or overspray.

Overspray does not always cause the death of your cherished plants but can cause spotting of their leaves, stunting, and leaf drops.

To protect your desired plants, use weed killers responsibly and follow the following guidelines.

Read the label

Labels will always warm you against creating fine droplets.

A high-pressure type of nozzle sprayer usually creates fine droplets that the wind can easily carry away.

Therefore, an appropriate choice of nozzle sprayers is vital.

Avoid Spraying Weed Killers During a Windy Day

Spray weed killers when the wind is calm to minimize overspray.

Spraying during windy days will drift the poison-containing spray to an undesired location, including the desired plants.

Moreover, drifting wind can harm your health as it is likely to drive the spray toward your nose.

Spraying on a windy day is also expensive and ineffective as the chemical is usually drifted away from the weeds, thus causing a lot of wastage.

Clean Spraying Materials Adequately

Adequately rinse sprayers and watering cans after use and dump the rinse water appropriately.

Avoid dumping the rinse water in locations that might channel it to your desired trees and shrubs.

It would be better if you had a sprayer or spraying can only for applying herbicides to avoid involuntarily exposing desired plants to weed killers.

Protect Trees and Shrubs When Spraying

Use plastic sheets or cardboard to cover your trees and shrubs during spraying.

The use of sheets will form a barrier that will minimize contact between plants and the herbicide. Remove the barriers after spraying is completed.

It is also important to avoid walking the sprayed area as you are likely to carry the chemical on your shoes to the undesired area.

Finally, avoid spraying on a sunny day to avoid intensifying damages of overspray.

Biological Weed Control

Biological weed control uses living organisms to kill and suppress weeds.

Some of the biological agents you can use to kill or control weed are;

  • Grazing animals like goats, sheep, and cows
  • Insects like ladybirds, chrysolite, tansy flea battle, and cinnabar moth
  • Bacteria
  • Fungi

Insects are extensively used in the biological control of weeds in integrated pest management or insect bio-control.

However, grazing animals to control and kill weeds should be done carefully since some animals consume both desirable trees and weeds.

Large animals like cows and goats can also add manure to the soil.

In summary, weeds can be killed by three methods;

  • Natural methods
  • Chemical methods
  • Biological method

The safety of the desired plants like trees and shrubs will depend on how each method is used.

For example, in chemical control, the mainstay of tree and shrub safety is dependent on minimizing their exposure to herbicides.

On the other hand, safety when using physical methods is dependent on minimizing soil disruption.