2,4-D requires 14 days to work and show full results, but plants may begin to show signs of wilting and dying within 48 hours after application. This makes 2,4-D a slow-acting herbicide, but it’s worth the wait because it kills weeds so effectively without harming your lawn.
Because 2,4-D remains active for an extended period of time, do not apply 2,4-D more than once every 30 days. Multiple applications of 2,4-D too close together can introduce very high levels of herbicide in the soil, which can damage your grass. Remain patient and let the 2,4-D do its work.
Table of Contents
Why Use 2,4-D Instead of Other Herbicides?
2,4-D may require as long as 14 days to live up to its weed killer potential, but it’s still one of the most popular selective herbicides used around the world. The reasons for 2,4-D’s widespread use are:
- Safe to use on most species of turfgrass.
- Kills a wide variety of broadleaf weeds.
- Kills weeds at a very high rate.
- Is not linked to any harmful effects on people and animals.
Most fast-acting herbicide sprays are non-selective, meaning they kill any plant they touch. These products, including Roundup, cannot be sprayed on lawns without harming the grass. Additionally, 2,4-D is so popular because it is a weed killer that consistently wipes out weeds. In contrast, some other herbicides struggle to kill common broadleaf weeds.
Importantly, while other chemical compounds are surrounded by controversy regarding their negative impact, 2,4-D has not been linked to cancer or other health concerns.
Tips for Increased 2,4-D Effectiveness
It’s possible to get more out of your 2,4-D by applying it under the right circumstances. By following these tips for the best time to apply 2,4-D, you will see faster results and more complete weed death.
- Apply when temperatures are 65–85℉.
- Apply on a windless day to prevent overspray and increased evaporation.
- Add a surfactant to any 2,4-D concentrate you mix yourself.
- Wait 6–8 hours after rain before applying.
- Apply when there is no rain in the forecast for 6–8 hours.
It’s essential to apply 2,4-D when temperatures are optimal. 2,4-D is ineffective at low temperatures and harmful to grass at very high temperatures. Meanwhile, low-wind, no-rain conditions prevent your 2,4-D from being carried away by wind or water. To review correct 2,4-D mixing practices, as well as how to add surfactants to boost effectiveness, review our guide on 2,4-D mixing rates.
How Often Can You Apply 2,4-D?
2,4-D herbicide should not be applied more than once per 30-day period. Although it has completed most of its work within 14 days, 2,4-D can linger in the soil for up to 30 days. If you apply 2,4-D multiple times within 30 days it may harm your grass. This damage comes in the form of yellowed, scorched, or dead patches of grass.
Do not perform several 2,4-D applications close together. It’s essential to allow time for 2,4-D to work. The weeds in your lawn may look unaffected a week after you’ve sprayed them, but the weed killer will catch up to them soon.
How Long Does it Take 2,4-D Weed Killer to Work?
Although you may begin to see some weed browning and wilting in as few as 48 hours, the herbicide’s life cycle requires much more time to fully attack plant systems and kill broadleaf weeds down to the root. 14 days are required to see the full impact of your 2,4-D application.
In order to get the best from 2,4-D weed killer, apply when temperatures are 65–85℉, there is no wind, and there is no rain in the forecast. This will allow your 2,4-D to act more quickly and prevent it from being evaporated or washed out of your yard.
To prevent harm to your turfgrass, apply your 2,4-D product no more than 1 time per 30 days. When used properly and with patience, 2,4-D is one of the best solutions for killing weeds growing in grass.