How Long Does Weed B Gon Take to Dry?

how long does weed b gon take to dry

Ortho Weed-B-Gon, like most lawn herbicides, evaporate after approximately 3 days. However, the active agents might still be present in the soil.

Weed-B-Gon is a very popular weedkiller since it tackles over 250 different kinds of weeds. It is also effective on crabgrass (we’ve reviewed the best crabgrass killers here).

The problem with using herbicide on your lawn is that it may affect more than just the unwanted weeds. The chemicals need some time to break down before it is safe for you, your children and pets to enjoy the lawn again.

Read on to find out more about how long Weed-B-Gon takes to dry and how to apply it safely.

What Is Ortho Weed-B-Gon?

Weed-B-Gon is a popular chemical herbicide for lawns produced by the Ortho brand. One of the main reasons why many households prefer this brand is that it claims to kill over 250 types of weeds, including most broadleaf weeds.

Another perk of this weed killer is that it does not affect lawn grass species. This is an impressive feat because it attacks weeds down to the roots.

Weed-B-Gon comes in the form of a liquid and must be diluted to get the appropriate concentration for the specific lawn. It is one of the easier herbicides to spread on a lawn.

How Weed-B-Gon Works

Ortho Weed-B-Gon is the type of herbicide that attacks weeds at the root. After application, the chemicals sink down into the soil to reach the roots.

While the roots are suffering damage, the leaves and stems that you see above ground suffer, as well. Weeds will start to wilt and yellow as the herbicide goes to work.

You may see initial effects after just 10 hours but it can take up to two weeks for the weeds to truly die. The weeds should not grow back until the following growing season in the next year.

How to Apply Weed-B-Gon: 6 Steps

Like most herbicides, there is an appropriate time to apply them. This is because the chemicals are more effective during specific stages of weed growth and during certain weather conditions.

Here are a few tips on how to apply Ortho Weed-B-Gon so that it is most effective.

1. Wait for the Weather to Cool Down

Too hot temperatures can cause the grass to burn. Also, the chemicals might evaporate too quickly – it requires time to sink into the soil and reach the weed roots.

The best time to apply Weed-B-Gon is when the temperature is between 45°F – 85°F. Sunny days are preferable but it more important that it won’t rain for the next 24 hours.

2. Apply Long Before Rain

Ortho Weed-B-Gon should be applied approximately 24 hours before a rain shower is expected. This should give it enough time to soak into the soil and prevents the rain from washing away the active agents.

3. Don’t Apply Weed-B-Gon More than Twice a Year

Ortho Weed-B-Gon is a powerful herbicide and the chemicals stay in the soil for a long time, even after the lawn already appears dry. Applying too much and too often can damage your lawn, instead of protecting it from weeds.

Weed-B-Gon takes about 14 days to work so wait at least two weeks to see if the first dose has had an effect. If there are no results after 14 days, it is possible to apply Weed-B-Gon for a second round.

This herbicide should not be applied on a lawn more than twice a year. So, if the weeds are not killed after 28 days, other measures may be needed.

4. Stay Off the Lawn Until It Is Dry

Ortho Weed-B-Gon takes approximately 24 – 78 hours to dry, depending on the weather conditions. Keep yourself, children and pets off the lawn until all the herbicide has evaporated.

5. Wait 14 Days Before Planting Grass Seed

Herbicides like Weed-B-Gon leave traces in the soil since their job is to attack weeds from their roots. These same chemicals may be safe for many already established grass types but it does stop new seedlings from germinating.

Avoid wasting your time, energy and money on grass by being patient after applying Weed-B-Gon. Wait at least 14 days after applying herbicide before sowing grass seeds.

6. Only Apply Ortho Weed-B-Gon to Lawns

Ortho Weed-B-Gon should only be applied on grass lawns. It is not suitable for areas where shrubs, trees, flowers or fruit growing plants will be planted.

Although herbicides are meant to break down, trace chemicals may still be found in the soil long after the standard of 14 days has passed.

Frequently Asked Questions:

How Long Does Weed-B-Gon Take to Work?

Weed-B-Gon starts working after just 10 hours, depending on the application method and weather conditions. After the first 10 hours weeds may start to wilt and yellow but it takes a further 1 – 2 weeks for the weeds to completely die off.

Weed-B-Gon Doesn’t Work. Why?

Weed-B-Gon may not work for several reasons including incorrect application method, unsuitable weather conditions and a resistant species. Make sure to carefully follow the instructions for the best results and prevent damage to the lawn.

Does Ortho Weed-B-Gon Kill Grass?

If applied incorrectly, Ortho Weed-B-Gon can kill certain grass species. Weed-B-Gon is safe for use on many common lawn grass types like bermudagrass, bluegrass, fescues, zoysia grass and more. Check the bottle to make sure it is safe for your lawn grass.


Ortho Weed-B-Gon is a suitable chemical herbicide for over 250 different weed species, mostly broadleaf weeds. At the same time, it is safe for many of the popular grass species used on lawns.

With any herbicide, correct application is very important to achieve the best results and avoid killing lawn grass, instead. Always carefully follow the instructions for safe dosages and application.

If applied correctly, Ortho Weed-B-Gon starts taking effect after just 10 hours and kills off all weeds within 1 – 2 weeks. After 24 – 78 hours it is safe to step on lawn again, depending on how long it takes to evaporate.

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