Pre-emergent herbicide is a lawn care treatment that stops weed seeds from germinating. It forms a protective barrier in the soil. Pre-emergent prevents weeds before they grow, making it a key part of proactive lawn care.
So, how long does pre emergent last? Most products last 3-5 months. That means one application covers a good portion of the growing season.
This article explains what pre-emergent is, when to apply it, how long it works, and what weeds it targets. We’ll also cover safety and why professional help may give you better results.
Key Takeaways
- Pre-emergent weed control lasts about 3-5 months
- Apply in early spring before weeds like crabgrass germinate
- Timing matters—adjust for your region and weather
- Targets summer annuals like crabgrass, not existing weeds
- Best used before the growing season starts
- Safe for established lawns but avoid use on new grass seed
- Split applications can extend protection
- Read the labels to follow exact instructions
What Is Pre-Emergent?
A pre-emergent herbicide prevents weed seeds from sprouting. It doesn’t kill existing weeds. It stops them before they start.
Once applied, it forms a barrier in the soil. When seeds try to grow, the barrier blocks them. This helps keep your lawn clean from unwanted growth.
When Should I Apply Pre-Emergent Weed Control?
Timing is everything. Apply a pre emergent before the weed seeds germinate. In most parts of the U.S., that means early spring. If you live in the Southeast, February through March is the sweet spot.
North Texas may start in late February. Cooler states like Massachusetts may need to wait until April. Watch the soil temperature. Once it hits 55 degrees for several days, it’s time to apply.
Late cold snaps? Delay your pre emergent application a bit. You want to catch the window before seeds pop.
How Long Does Pre-Emergent Weed Control Last?
Most pre emergents last about 3–5 months. That’s long enough to cover the early and middle parts of the growing season.
But if you live in an area with long summers, you may need to apply it again. That’s called a split application. It helps keep the protective barrier in place.
Read the labels. Different types of pre emergent products vary in strength and duration. For best results, consult a local lawn care professional.
What Types of Weeds Does It Target?
Pre emergent weed control targets summer annual weeds.
These include:
- Crabgrass
- Goosegrass
- Spurge
- Other common summer weeds
It works only if the weed hasn’t sprouted. Pre emergent prevents seeds from germinating. If the weed is already growing, you’ll need a post emergent product instead.
Is Pre-Emergent Weed Control Safe for My Lawn?
Yes, it’s safe for most established lawns. But it’s not good for newly seeded lawns. If you just planted grass seed, skip the pre emergent. It may block your desired grass from growing.
Also avoid using it near flower beds or new plantings unless the label says it’s okay.
Trust Lawn Sense’s Pre Emergent Treatment Services
Preventing weeds saves time, money, and effort. Pre emergents help keep your lawn clean, green, and strong. Lawn Sense means no nonsense. Their team serves homeowners in Dallas, TX, and nearby areas.
Their services improve your lawn’s health, appearance, and balance. Stop weeds before they grow. Call Lawn Sense for pre emergent treatment today.
FAQs
How long does pre emergent last?
Most pre emergents last 3–5 months, depending on the product and conditions.
Can I apply grass seed and pre emergent at the same time?
No. Pre emergent will block grass seed from sprouting. Wait until your new lawn is established.
Do I need to water after a pre emergent application?
Yes. Light watering helps activate the product and create the soil barrier.
Does pre emergent kill existing weeds?
No. Use a post emergent for visible weeds.
Can I use pre emergent in the fall?
Yes, if you’re targeting winter weeds. Fall applications can stop weeds like annual bluegrass.
Is it safe for pets?
Most products are safe once dry. Still, read the labels and follow instructions.
What happens if I apply too early?
You may miss the window when weed seeds try to germinate. Watch the soil temp to time it right.
Final Thoughts
Pre emergents are a smart move for preventing weeds before they start. They last 3–5 months and help your lawn stay healthy. Time it right, use the correct product, and consider a second round mid-season.
Need help? Trust Lawn Sense.