What Kills Weeds But Not Flowers? Natural and Chemical Options

Weeds can be stubborn when they invade your flower garden. They compete for precious nutrients with flowers, prove challenging to eliminate, and make your garden look unsightly. As a flower enthusiast, you’ll want to kill these weeds to sustain your gorgeous garden.

So, what kills weeds but not flowers? While chemical herbicides are famous for killing weeds, they can harm nearby flowers. These weed killers are also toxic to pests, humans, and the environment.

Luckily, this article looks into various natural weed killers you can use to eliminate uninvited weeds. The good news is that these natural weed killers won’t harm your flowers when appropriately used.

Natural Weed Killers That Won’t Harm Flowers

Most natural weed killers discussed below are available at our homes. They’re chemical-free products that will leave your flowers alive after application. Let’s discuss them.


Gardeners primarily use mulch to improve moisture in the soil to keep the nearby vegetation hydrated. Besides moisturizing the soil, mulch can act as a natural weed killer.

When using mulch as a weed killer, spread a thick layer to prevent sunlight from penetrating. Some aggressive weeds can break through a thin layer of mulch. So always use the right amount of mulch. Generally, a 3- to 4-inch thick layer will do the trick.

When laying your mulch, cover the affected areas. You can spread the mulch near the base of your flowers and the surrounding areas without covering flower leaves.

The goal is to suppress weeds and ensure they don’t have access to light. Eventually, the weeds will lack food, wither and die.

After killing weeds, mulch will eventually break down and provide the soil with valuable nutrients. When looking for the most effective mulch for your flower garden, go for grass clippings, pine bark, straw, or shredded leaves.

Boiling Water

When used correctly, boiling water is another effective weed killer that won’t kill your flowers. This technique works best in flower gardens with fewer weeds.

Be cautious when using boiling water, as it can harm the flowers it comes into contact with.

To use boiling water effectively, pour it directly on the weeds. The hot steam and water will instantly kill the weeds’ leaves, branches, and stems. The hot water will go through the soil and destroy the root structure.

Boiling water will also kill weed seeds in the soil.

Note that boiling water is more effective when killing young weeds. More established weeds can pull resources using the deep root system and recover.


When looking for what kills weeds but not flowers, salt will always be among the most recommended options. However, salt is nonselective and can harm any nearby plant.

Mix salt with water and spray it directly on the weeds when using salt as a weed killer but not flowers. This mixture dehydrates the weeds by sucking all the moisture in the leaves, branches, and stems. Salt will also travel through the soil to the roots and dehydrate them.

When the weeds lack water, they stop making food and dry out.

While salt is an effective weed killer, it will poison your flower garden for many years. It moves into the soil and spreads all over while watering or after rain. If it gets into contact with flowers, it might restrict root growth and lead to stunted growth.

Baking Soda

Baking soda is an ideal alternative to commercial weed killers that won’t harm your flowers. It has high salt content and will dehydrate weeds and eventually kill them.

You should, however, avoid using baking soda around your flowers. Moreover, don’t spray this ingredient on weeds on a windy day, as it can land on your flowers.

To use baking soda effectively, sprinkle it directly on the weeds. The product will dehydrate the weeds and kill them. You can apply one teaspoon of baking soda per weed and ensure it coats the entire plant.


Vinegar is a great at-home weed killer for your flower garden. It doesn’t harm established flowers when used in small amounts.

Start by mixing vinegar, water, and dish soap and put it into a spray bottle. Then spray the mixture directly on the weeds.

Vinegar is highly acidic and will dry out the weeds in a few days. White vinegar will do the job, but if you’re looking for an affordable option, choose apple cider vinegar. The solution will break down the weeds’ cell walls and kill them without harming the nearby flowers.

Spraying vinegar on the weeds during sunny days and when there’s little wind is advisable. You don’t want the wind to blow the mixture over your flowers.

Caution: Wear protective gloves since vinegar can erode your skin and result in chemical burns.

Lemon Juice

If you don’t have vinegar at home, you can use lemon juice to kill weeds but not flowers. Most gardeners prefer mixing lemon juice with vinegar to make a highly acidic solution.

Like vinegar, lemon juice contains acid that will burn the weeds, killing them in a few days. Mix lemon juice with water and put the mixture into a spray bottle. Then, spray the mixture directly on the weeds.

Lemon juice will travel through the soil and lower the soil pH, killing the weeds. Remember not to use lemon juice on a windy day to avoid spraying your flowers.

Weed Torch

Some gardeners might choose a weed torch when looking for what kills weeds but not flowers. Weed torch is a no-spray and chemical-free product that can quickly handle unsightly weeds. It works instantly by burning the foliage and killing weeds as soon as they get into contact with the flame.

Be cautious when using a weed torch to kill weeds in your flower garden. The flame can accidentally hit your flowers and kill them. Use a weed torch when there’s little to no wind.

Avoid using a weed torch in extremely dry areas with dry leaves to prevent creating a wildfire. Likewise, don’t use a weed torch near flammable materials such as plastics.


You can use the sun to kill weeds but not flowers in various ways. If your flower garden accesses direct sunlight, you can use solarization to eliminate weeds. This technique works best in summer when there’s plenty of sun.

Solarization involves placing a transparent plastic film over the weeds. This method cuts out moisture and oxygen and concentrates the sun’s heat. The heat eventually burns and kills weeds. The good news is that solarization will kill weed seeds, pests, and pathogens.

When using solarization as a weed-killing technique, do not cover your flowers. 

Follow these steps to boost your success rate:

  • Water and aerate the areas you want to kill weeds.
  • Cover the area with a clear plastic film.
  • Seal the edges of the plastic film with sand or stones. This step will ensure that no moisture or oxygen gets inside.
  • Wait for about 2-4 weeks but always check the progress.
  • Once all weeds are dead, remove the film. You can now aerate and water the weed-free soil.

Note that solarization creates intense heat that can kill beneficial microorganisms in the soil.

Can You Kill Weeds by Pulling Them Out?

Pulling weeds out by hand is a traditional method for eliminating unwanted plants in the garden. While this method entails much manual work, you can make it easier by pulling weeds out when you spot them.

Pull them out while watering, aerating, or fertilizing the flower garden. With time, you’ll eliminate all the weeds without killing flowers. Ensure to pull weeds out when they’re still young. Mature weeds will likely flower and spread seeds on the ground.

Follow these steps to make your job more rewarding:

  • Dampen the affected area.
  • Wear protective gardening gloves and pull the weeds out. Ensure to grab the unwanted plant by its base and pull it out, including its entire root system.
  • If the weed breaks off, use a trowel to dig it out.

What Chemical Product Kills Weeds Without Harming Flowers?

Chemical products such as glyphosate or dicamba can kill weeds without harming your flowers. However, you’ll need to exercise caution when using a chemical product as a weed killer.

Glyphosate and dicamba are nonselective products and can kill flowers they come into contact with. Ensure to apply your product directly to the weeds without spraying the flowers.

Herbicides that use glyphosate or dicamba as active ingredients work best on perennial weeds with established leaves. Some of these weeds include dandelions, thistles, bindweed, and docks. The herbicide moves down to the roots and kills the whole plant.

You’ll also need to consider the weather when applying chemical products to your flower garden. Spraying the herbicides on a rainy or windy day can drift the product toward your flowers and kill them.

Final Thoughts

Hopefully, this article answers the question, “What kills weeds but not flowers?” If you wish to reclaim your flower garden’s beauty, use natural weed killers. You can use mulch, boiling water, salt, lemon juice, weed torch, or solarization. Alternatively, you can go for chemical-based products such as glyphosate or dicamba.

Exercise caution when using your preferred weed killer to avoid harming flowers. If you spot fewer weeds around your flower garden, uproot them using your hands or a trowel.