Herbicides Explained

Weeds can be described as any plant growing in an area where it is not wanted.

Weeds can be small (clover) or large (Bugweed) in size. They are typically fast growing and spread rapidly impacting on plant growth in and around them. In gardens, weed growth most commonly refers to weeds growing in existing lawns. Weed growth in paving, vegetable gardens and flower beds are also problematic. Weeds are characterized as: narrowleafed (grasses), broad-leafed or woody. Large weeds can often be removed by hand, but the use of an effective herbicide can eliminate hours of arduous weeding.

There are two types of herbicides:

  • Selective herbicides control certain types of weeds – either broad-leafed or grass-like weeds
  • Non-selective herbicides control and kill ALL plant types with which it comes into contact.

Selective Herbicides

These products are effective on either broad-leaf or grass type plants.
The application of a broadleaf herbicide will affect and control the growth of broadleaf plants. As such, this herbicide can safely be applied onto existing lawns, but will control broadleaf weeds.
A grass herbicide controls the growth of grass type (parallel veined) plants.  Grass herbicides can safely be applied to flower beds and will have no impact on broadleaf plants, but will control and impact on grasses.

Non selective herbicides

Non selective herbicides are effective on all growing plants. These herbicides should be applied with extreme care as they have been developed to retard all types of plant growth.  Drift from the herbicide application will impact on the plant growth in the vicinity, so herbicides should always only be applied in cool, calm conditions.

Herbicides are most effective on actively growing plants.

The solution is carried by the sap of the plant. The faster the plant is growing, the quicker the solution will be translocated through the plant, impacting on plant growth.  Applications done during less active growth period are also effective, however the results will take longer to be observed.

Weeds are persistent. Most weeds are not controlled after only one application and several, consecutive applications are recommended. Applications should be done every 2 weeks during the growing season and should continue until the weeds have been successfully controlled.

Remember – weeds are fast growing and quick to set and disperse seed. These seeds germinate to form new weeds, so regular herbicide applications are essential.

Plantland’s recommendation for controlling broadleaf weeds in lawns

Apply a selective broad leaf herbicide to remove unwanted weeds. Efekto Hormoban APM and Efekto Turfweeder APM can be mixed and sprayed over the lawn using an Efekto pressure sprayer.
Buffalo grass is sensitive to many herbicides but Efekto Banweed MCPA is safe to use on buffalo lawns Efekto’s No Weed Lawn RTU is a convenient ready to use product ideal for small lawned areas.
Efekto’s new granular herbicide Spread and Kill for Weeds is easy to use. Apply evenly at a rate of 50 g per m2 of lawn and water in afterward.
Always read and follow the label and make sure that the product is suitable for your grass type

Herbicide applications should be done evenly across your lawn. The easiest way to achieve this is to use a qualitypressure sprayer – Plantland has a selection of sizes in store for you to consider.

The herbicide solution should be applied to cover the growing leaf blades to the point of ‘run off’. Any excess solution will ‘run off’ the foliage into the soil where it is ineffective – so don’t ‘over apply’.

Applications should be done in cool and dry conditions.  Do not water or irrigate the lawn for a period of 3 hours after the application.  Should rain fall within 3 hours of the application it is advisable to repeat the application.

Always use the entire contents of the herbicide solution, so only mix as much solution as is required. Do not keep the solution for a later application. After the application has been completed, be sure to rinse out the pressure sprayer at least 3 times with clean water to remove all herbicide traces prior to the sprayers next use.

Gardening Tip: A wetter such as G49 or INSURE should always be added to herbicide solutions to ensure proper coverage is achieved.