Weed Control for Home Lawns and Gardens

When using any type of pesticide it is important to read and follow the instructions on the label. All chemicals are different and their compositions make them unique in their effects on plants versus humans. Just because a chemical is not highly toxic to a broad variety of plants does not mean that it is not highly toxic to human, and vice versa.  Respect all of them.

Weeds can be characterized as selected vegetation that is undesired within other vegetation thatis selectively desired. (The operative term here is selectively desired.)

Fortunately there are chemical herbicides (weed killers) that are selective in the types of weeds that they kill or affect. In general, there are four types of selective Herbicides:

1)     Grass Killers

Grass Killers kill grasses without harming most of the surrounding foliage with leaves on them.  These types of chemicals can be used directly over plants and planter beds to kill unwanted grasses in the planter bed.  Fortunately, this chemical works well on Bermuda Grass as well. Read the label carefully to determine which plants it can be used on.  If you have a leaf plant that is not listed on the label it is likely because it has not been tested on that leafy species. We recommend testing it over one plant before applying it over many of the same that you have in your garden.

There are two commercially available Grass Killing Herbicides that we recommend: Fuslaid and Post. Both are spray on chemicals that you mix with water and apply to grass weeds that are growing in ornamental planter beds.  Follow the application directions and rates carefully.  Typically they take about two weeks from the time of application to take effect.

2)     Broad Leaf Killers

Broad Leaf Killers are more or less the opposite of Grass Killers. They can be applied directly over most lawns and will selectively kill the broad leafs without harm to the lawn.  These chemicals are very volatile and, while relatively safe for humans, drift will severely damage adjacent plantings.  Spray on low wind days with low pressure to reduce spray drift.

Weed B Gone is a very effective broad leaf killer that is available on the retail market.  A newer product, Turflon, is a broad leaf killer that is not registered for use on Bermuda or St. Augustine because it will severely damage or kill those species of grasses. Turflon is not labeled as a Bermuda Grass killer, but is commonly used to control Bermuda Grass within fine turf grass lawns. Turflon should be used on Blue, Rye and Fescue grasses.

Both Weed B Gone and Turflon are spray on chemicals that you mix with water and apply to lawns in order to kill weeds.  Follow the application directions and rates carefully including ambient temperature restrictions.

As mentioned above, Broad Leaf herbicides are very strong and should not be used on shrubs or leafy ground covers that you wish to keep.

3)     Broad Spectrums Non-Selective Herbicides

Both types of herbicides mentioned above are selective in what they will have an effect on. They are specific in that they kill either grass or broad leafed plants.

Non-Selective Herbicides are self-explanatory in that they are not selective in what they kill. They generally damage or kill virtually any plant material they contact. Round-Up falls into this category.

Round-Up is a non-selective broad spectrum herbicide that is intended to kill all herbaceous plants that it touches. It is especially helpful for sidewalk cracks and areas with no desired plantings.

4)     Seed Killers

The fourth type of selective herbicide is a Pre Emerchant Herbicide (also known as a seed killer) that will kill seeds but should not harm existing plants or lawns (depending on the label).

Ronstaris a granular product that will not harm most common plants, nor is it harmful to Blue, Rye or Fescue Grasses. Ronstar is available in 40 or 50 pound bags for about $60.00.  This product is best applied with a Whirlybird spreader at the approximate rate of four pounds per 1000 square feet, and is effective for about three to four months.


Upon application of any of the weed killers referenced above, it would be prudent to apply this product to minimize reproduction of weeds via seeds that may be left behind or that blow in from neighbors.  At such time that your weed population is under control, it would be advisable to regularly treat with Ronstar Pre Emerchant (seed killer) as necessary for prevention.  Once the weed problem is under control, you can cut back the use of Ronstar to an as needed basis. It is recommended to use Ronstar Pre Emerchant during rainy seasons as well to control new season seeds that tend to emerge.

RonstarPre Emergent is not recommended for use on perennials and annuals, as it will severely damage the plants. Spot treating with the other weed killers will be helpful (and necessary) from time to time. As always, be sure to read the label as some Pre Emerchant herbicides may harm some plantings, especially herbatious type plants such as annuals.

If your lawn is dense and has become resistant to weed population, and you’re at the point where you can easily control the lawn weeds with spot treatment, then avoid the repetitive applications of Ronstar Pre Emerchant seed killers as it does have nominal negative impact on the vitality and maturing of a fine lawn.


Chemical Absorption

Chemicals are absorbed by the plants in several different ways. Most applications are for contact application. Meaning the chemical must come in contact with the foliage or with some insecticides with the insect itself to be effective. A few chemicals are absorbed through root absorption and are usually applied as a soil drench or root feeder.

There are such things as bark injections, however this is not recommended for someone who is new to this process. The other solutions mentioned above are easier and typically just as effective.



Translocation is a term that implies the chemical is absorbed into the plant and flows through and with the plant fluids.

Pesticide translocation refers to the plant absorbing the chemical into the tissue and fluids of the plant. Translocating pesticides are preferred as they affect the entire plant from roots to leaf.

A translocating herbicide will translocate to kill beyond what it contacts; it will also kill the roots.

A translocating insecticide will actually make the plant poisonous to the target insect. As the insect preys on the plant it will ingest the insecticide that has translocated through the plant.

Disclaimer: These tips are intended to be informative in a general sense but in no way are to be construed as a recommendation for use of any pesticide or product. Recommendations are general and will vary for each unique landscape.