How To Control Lawn Weeds

Most lawn owners dream of a perfect lush green lawn that is even in appearance and weed free. The reality however is that our lawn will have a variety of weeds often with white or yellow flowers that will distract from the green and even surface that we desire.

See more about Identifying Weeds here.

We need to control weeds not only because they are unsightly, but because they also compete with our desirable grasses for light, water, space and nutrients which are need in order to thrive.

Weeds are inevitable – It’s how you control them that matters. It takes time and effort to address weed problems in your lawn and hard surfaces around your garden. At Lawnscience we can discuss a complete lawn care treatment programme for you and your lawn, which includes Weed Control and Total Weed Control for hard surfaces. Contact your local Lawnscience Professional for further information.

Once you have made the decision to control weeds you must consider whether you want to use Non-Chemical means, such as digging out the weeds, or the Chemical option.

 What are the Non-Chemical options?

A wide lawn on the left and a photo of lawn aeration infographic at the right
Lawn Aeration


  •  Feeding, Aerating and Scarifying will encourage your lawn’s grass to be more vigorous and make it more difficult for weeds to thrive.

Talk to your local Lawnscience Professional to find out more about these important treatments for a lush green and healthy lawn

  •  Dig out any weeds manually using a garden folk
  •  Avoid mowing too closely as it can weaken the grass and allow the weeds to grow and compete with your desirable grasses
  •  Rake your lawn prior to mowing as this will discourage any creeping weeds such as White Clover, Creeping Buttercup and Yarrow
  •  Mow your lawn frequently, once a week on a medium setting. This will stop the worst of the weeds from flowering
  •  Spike your lawn frequently, once every 4-6 weeks, this will reduce compaction. After spiking apply a turf dressing (a combination of sand and compost) this will be beneficial  to your lawn and will give your grass a boost


What are Chemical (Herbicide) options?


Herbicides are chemicals that kill weeds. There are Selective and Non-Selective herbicide controls.

Selective herbicides will kill targeted weeds without damaging any desirable grass species. These are the types of herbicides to use when treating weeds in your lawn.

Non-Selective herbicides will kill all vegetation, including any desirable grass species. These are the types of herbicides to use either when you are killing weeds in hard surfaces, such as patios or driveways, or when you are trying to completely kill weeds, and grass within a lawn, prior to laying or seeding a new lawn.

How do Chemical Weed Killers work?A before and after photo of a weed after a lawn weed control treatment


Active ingredients in weed killers will either disrupt the metabolic processes of the plants cells, which will cause them to die, or they will stimulate over growth within the plant. This will result in the plant being unable to take up sufficient nutrients to keep up with the increased growth rate, which effectively causes the rapidly growing plant to die.

There are many herbicides that will contain two or more active ingredients for broad-spectrum weed control. Generally, two or more active ingredients will provide a much improved control compared to just one single herbicide ingredient.

Get selective when choosing Weed Control


There are no single herbicides that will provide control of all types of weeds. Some herbicides that are effective in controlling broadleaf weeds will only provide poor control for Grassy Weeds. Many herbicides contain more than one ingredient to cover a broader spectrum of weeds. Make sure you choose a weed killer that will effectively control the weeds you intend to remove.

You must be very cautious, when applying herbicides to newly seeded lawns or areas you plan on seeding. The label should tell you how long to wait before you sow lawn seed to an area.

Once a product has been chosen it is important to follow the manufacturer’s instructions and ensure the conditions are right before applying the product

Equipment used to apply Weed KillersA lawn expert spraying a lawn with liquid sprayer


Weed killers can be applied by using a variety of equipment. Liquid weed killers will be applied using a watering can or sprayer. When applying with a sprayer make sure that it has a clean nozzle and operates freely so it can emit the same volume of spray.  If the nozzle is applying more or less product than it should be, this can lead to stripes in the lawn and not work effectively at controlling weeds.

It is important to read the product label and follow the manufacturer’s recommendations and guidelines before you make your choice and start to apply any herbicide. It is also essential to wear suitable protective clothing.

At Lawnscience we know all about herbicides and how best to target weeds in your lawn. We can help you get that lush green and weed free lawn all through the year. Contact your local Lawnscience Professional to arrange a visit to you and your lawn and discuss the options best for you.

When to apply Weed Killer


Be careful not to apply lawn weed killer on your entire lawn in early Spring as there will be a variety of weeds that will not surface until later in the year. It may be necessary to spot treat with a weed killer or remove by hand. You may need to repeat an application of weed killer but this must be done prior to cold weather.

Read the product’s label to make sure repeat treatments are appropriate

We recommend you follow these guidelines and lawn care tips before any weed killer is applied to your lawn:

  •  Check the label for any adverse effects to children, pets or desirable plants in your garden
  •  User a slightly higher mowing setting, if you mow too close you will chop the leaves off the weeds and there is not enough surface of the weed left to target
  •  Apply after a fertilisation treatment
  •  When moisture is available in the soil, otherwise you can harm the grass in drought conditions. Avoid strong sunshine
  •  In calm weather as strong wind will blow the product away from the targeted areas
  •  Avoid frost or freezing conditions We know that getting a lush green, healthy and weed free lawn takes effort and time.

If you need help achieving your dream lawn we can help with any questions you have and we have a number of lawn care treatment programmes that we can discuss with you, to make sure your lawn looks it’s best all year round. Contact your local Lawnscience Professional for more information.