Maintaining a healthy lawn is a source of pride for many homeowners and gardeners. However, if you don't pay attention, weeds can quickly take over and damage it. They do so by competing with grass for nutrients, water, and sunlight, wreaking havoc. Therefore, it's essential to apply weed control in your care routine.

One of the most common methods of weed control is the use of weed killers. But when is the best time to apply them? Explore the best time of year to use a weed killer and find tips for keeping your lawn weed-free!

Know Your Enemy

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The first step in fighting weeds is correctly identifying them. Knowing your enemy and its life cycle will help you to choose the most effective tool to combat it without damaging the lawn. There are three main classifications of weeds based on how long they live: Perennial weeds, biennial weeds, and annual weeds.

Perennial Weeds

Perennial weeds are the most persistent and challenging to manage, as they grow back year after year. They are divided into two kinds:

• Simple perennials - They are also known as solitary perennials, grow individually, and have separate root systems. They only spread by seed and can live for many years. Common examples include curly dock, plantains, and dandelions.
• Spreading perennials - They spread through seed and vegetative reproduction using rhizomes or stolons, giving rise to dozens of new plants. They can quickly take over landscape plantings and lawns. Common examples include yellow nutsedge, ground ivy, and clover.

Biennial Weeds

Biennial weeds have a two-year life cycle, growing foliage in their first year and producing flowers and seeds in their second year. They can sometimes be mistaken for perennials due to their large taproots. They include weeds such as burdock, evening primrose, and mullein.

Annual Weeds

Annual weeds complete their life cycle in a single growing season, growing, flowering, and producing seeds all in one year. We can divide annual weeds into two types:

• Summer annuals - They emerge in spring or early summer and grow and produce seed before being killed by fall frost. They can be hard to manage, as they thrive in warm conditions. Examples include crabgrass, knotweed, and prostrate spurge.
• Winter annuals - These weeds grow from seed in late summer or early fall, survive winter, then die the next summer after flowering and producing seed. They cannot tolerate hot summer conditions. They include yellow rockets, common chickweed, and annual bluegrass. 

Types of Weed Killer

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When choosing a weed killer for your lawn, consider the type of weed you want to control and apply the herbicide at the appropriate rate to avoid harming your grass.

There are two main types of weed killers: pre-emergent herbicides and post-emergent herbicides. Each targets weeds at different stages of their growth cycle.

Pre-Emergent Herbicides

These herbicides prevent weed seeds from germinating, making them an effective tool for controlling them before they become established. They are most effective against annual weeds like crabgrass, chickweed, and common purslane. For the best results, use them once the soil in the top inch is at least 50 to 55 degrees Fahrenheit.

Post-Emergent Herbicides

They kill existing weeds and are available in both selective and non-selective formulations. Selective herbicides only target specific types of weeds, while non-selective herbicides kill all plants, including desirable ones. Post-emergent herbicides are most effective against perennial weeds like dandelions, clover, and thistle.

The Best Time to Apply Weed Killer

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The best time of year to apply weed killer to your lawn depends on several factors, including the weed type, the growth stage of the weed, and the season. Generally, it's best to spread weed killer during the weed's active growth period, when it's most vulnerable to control methods.

Here's a breakdown of the best time to use weed killer based on seasonal variations:

Spring

In the early spring, weeds begin to grow fast and emerge from dormancy. It is an ideal time to apply a pre-emergent herbicide, which can prevent weed seeds from germinating and establishing themselves in your lawn. Many gardeners recommend a second application eight weeks later for stubborn weeds.

You can also try post-emergent herbicides in the spring when weeds appear regularly on your grass.

Summer

During the summer, weeds are in full bloom. It's a perfect moment to apply post-emergent herbicides to kill existing weeds and prevent new ones from growing.

Fall

In the fall, many weeds are preparing to go dormant for the winter, making it an ideal time to apply post-emergent herbicides. It is also an excellent phase to fight perennial weeds, as they are more susceptible to control methods during this season.

Tips on Applying Weed Killer

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You must know how to properly apply weed killer to control weeds effectively, not harm your lawn and desirable plants, and stay safe.

Before you start, read the manufacturer's instructions to understand the recommended application rate, timing, and safety precautions. Avoid applicating herbicide on windy days to prevent it from carrying to unintended areas, potentially harming desirable plants, or polluting nearby water sources.

Use proper equipment to ensure even and accurate application. Wear gloves, long-sleeved shirts, and pants to protect your skin and reduce the risk of accidental exposure.

Keep children and pets away from the treated area until the herbicide has dried completely to reduce the risk of accidental exposure.

Keep Your Lawn Weed-Free

Controlling weeds is an essential aspect of maintaining a vibrant lawn. To effectively fight weeds, understand the different types of weeds and the best time to apply weed killer. By using pre-emergent herbicides in the spring and post-emergent herbicides in the summer and fall, you can control them to keep your lawn looking its best.

Remember to always read the label and follow the manufacturer's instructions carefully when applying weed killer. Also, take appropriate safety precautions and use the right equipment to ensure your lawn remains healthy and weed-free.

Do you know other ways to combat weeds? Share them below!