Types of Weeds

There are three main classifications of weeds:

  • Annuals: grow and produce seeds, then die within a single year. Some annuals may survive a second year in warmer climates. For annual weeds are the easiest to kill.
  • Biennials: live for two years. First year is vegetative development and the second year is flowering and seed development.
  • Perennials: live from season to season and produce seeds annually.

Weed Control By Hand

Manually removing unwanted weeds by hand or with garden tools is the most selective and environmentally friendly way to control weeds. Here are some tips to keep in mind when using this weed control method:

  • It is exponentially easier to remove them after a good rainfall.
  • Attack a weed as soon as it shows up.
  • Pull at the base, lifting out as much root as possible.
  • For larger weeds with extensive roots, like thistles and dandelions, use a garden fork, spike or slim trowel.

Weed Control & Prevention By Herbicides

Since manual weed removal isn’t a practical method for large areas or places that are overgrown with weeds. In these cases, the best option may be to use herbicides. When done properly, herbicides are extremely effective at combating weed invasion and eliminating weeds.

There are two types of herbicides:

  • Systemic herbicides enter the plant through the roots and leaves and travel through the inside of the plant.
  • Contact herbicides kill from the outside and work their way in. By attacking the exposed parts of the plant, contact herbicides kill the weed by reducing its ability to feed itself through the process of photosynthesis.

Within these two categories, herbicides may also be selective or nonselective:

  • Selective herbicides, kill only certain plants and only work when you applied as directed. These products remove weeds without killing the lawn where the weeds grow.
  • Nonselective herbicides kill all plants they come into contact with. These are best used when preparing to establish a new lawn. When used, all living vegetation can be removed from an area, which gives you a clean slate to work with.

Pre-emergent herbicides

Pre-emergent herbicides

Designed for application before the targeted weed germinates, and are an effective preventative method for controlling weeds. Pre-emergent herbicides establish a chemical barrier that don’t kill established plants, but are great when used for preventative measures. The protective barrier breaks down in six to eight weeks, therefore requiring proper timing to be effective. It is a best practice to apply them early in the season. Use caution during application because pre-emergent may harm some plants and turf grasses.


Herbicides are designed to attack weeds that are already growing. All contact weed killers are post-emergent. It is a best practice to apply post-emergent later in the growing season, after weeds have grown but before they seed.