When your lawn is speckled with odd plants and flowers you have a weed problem. Our guide to weed control for your lawn will cover the ways you can get your lawn weed free, green, and healthy again, and capable of resisting weed invasion.
Before you start using herbicides on your lawn, it is important to know the weed type you are dealing with. Why? Because some herbicides only target specific lawn weeds. For example, a herbicide labelled for sedge control will not do any good against broadleaf weeds.
In Australia there are three types of weeds: Broadleaf weeds, grassy weeds, and grass-like weeds.
Use LawnPride Lawn Weeds Identification.
Broadleaf weeds are easy to spot because they look nothing like grass. Their wide leaves have a main vein running down the centre. Common Broadleaf weeds include:
- Cars Ear, Flatweed
- Creeping Oxalis
- Khaki weed
- Medic, Burr Medic
Grassy weeds are true grasses or monocots. Distinguishing between your lawn and a grassy weed can prove difficult, as they often look similar. Sometimes your lawn can become a weed in certain areas, such as your couch lawn invading your garden. The most common grass weeds in Australia are:
Grass-like weeds are not true grasses, but their leaves are usually long and thin like grass. Grass-like weeds often grow much faster than turfgrass and may have a different colour than the rest of your lawn.
Examples of grass-like weeds include:
- Mullumbimby Couch
Pre-Emergent vs. Post-Emergent Herbicides
When weeds have invaded a lawn, many people solve the problem with a herbicide. Herbicides are readily available from a lawn care specialist such as LawnPride, and the herbicide options offered typically provide reliable results.
When choosing a herbicide, you will first need to decide whether you need a pre-emergent herbicide or post-emergent herbicide. Here is the difference between the two:
Pre-emergent herbicide prevents weeds from germinating. Apply a pre-emergent herbicide when you want to prevent new weeds in your lawn.
Post-emergent herbicide controls existing weeds. When you have weeds in your lawn, control them with a post-emergent herbicide.
When to Apply a Pre-Emergent Herbicide
Preventing weed growth is all about having a protective barrier that prevents weeds from germinating. If you apply pre-emergent herbicide when the weed seeds have already germinated, you have missed your chance to stop them growing. These emerged weeds will need to be controlled using a post emergent herbicide.
Pre-emergent herbicides such as Barricade and Spartan, give six months control from weeds germinating in your lawn. Once the pre-emergent barrier is in your soil, you can focus on controlling any weeds that have emerged in your lawn with a post emergent herbicide that controls the weeds you have.
Selective vs. Non-Selective Herbicides
You will find that there are many herbicide products. Some of these herbicides target specific weeds, while others will kill (or prevent the growth of) any plant they come in contact with.
Selective herbicides are herbicides that selectively target specific weeds. For example, if you apply a selective herbicide that targets broadleaf weeds, you will not need to worry about it killing your grass.
Before using a selective herbicide, correctly identify the weed you wish to exterminate. Otherwise, you risk losing money (and time) on a herbicide that targets the wrong weed.
A non-selective herbicide will kill any plant it touches, including your grass. It cannot distinguish between different plant types, which is why you should use only non-selective herbicide for weed control in areas where you want to kill all plants. Some carefully applied treatments via a weed wand or wiping device can be useful for tough to kill weeds such as Wiregrass but all care must be taken not to touch, drip or walk it on your lawn as a non-selective herbicide will everything it touches.
How to Prevent Weeds in your Lawn
Pre-emergent herbicide might seem like the most effective weed prevention method, but a healthy lawn is your best defence to preventing weeds from growing in your lawn. The healthier your lawn, the less likely it will grow weeds.
Maintaining a Healthy Lawn
Apply a controlled release lawn fertiliser: Your turf needs nutrients to grow well, and a professional turf fertiliser releases the nutrition of an extended period to keep your lawn.
Remove thatch: Thatch is the layer of living and dead organic material that accumulates between the soil surface and turf blades. A thick thatch layer can invite pests and diseases.
Relieve compacted soil: Your lawn will struggle to absorb oxygen, water, and nutrients if its soil is compacted. Relieve compacted soil with core aeration.
Water the right way: Watering less often and for long periods encourages a deep, healthy root system. Watering too often and for short periods encourages a shallow, weak root system. The best time to water the lawn is before 9 am in Australia. Avoid watering in the evenings.
Mow the right way: Mowing too low will stress your turf and make it vulnerable to weeds. Never cut off more than one-third of the grass blade’s height in a single mow. If your mowing low, remember to bump up the nutrition to counter the stress on your lawn.
Control pests and diseases: Lawn diseases and pests can seriously damage your lawn, so consider the use of a product such as Acelepryn to proactively control lawn grub before it is a problem. Disease control, once identified can be managed using a suitable fungicide.