Crabgrass Rescue for Bermuda, Zoysia, and Bahia
You missed the pre-emergent window. Or you did treat, but those stubborn little bastards are still popping up. Now it’s late spring or summer, the crabgrass is already up and spreading, and you need to kill it without waiting until next spring to start over. The good news: bermuda, zoysia, and bahia are all tolerant of the most effective post-emergent crabgrass killer on the market. The bad news: you still need to use it correctly, or it won’t work.
This page is for warm-season lawns only. If you have St. Augustine or centipede, stop here and read this instead. The standard rescue product will hurt those grasses. If you have fescue, bluegrass, or perennial ryegrass, go here.
The Active Ingredient: Quinclorac
Quinclorac is the rescue product. It’s a synthetic auxin herbicide. It kills crabgrass at every growth stage, from small seedlings to mature multi-tiller mats, while leaving bermuda, zoysia, and bahia unharmed at label rates. It’s the active ingredient in Drive XLR8 (the BASF branded original) and in generics sold as Quinclorac 75 DF and liquid quinclorac concentrates. The generic versions cost less than the brand name and contain the same active ingredient.
Quinclorac does not control goosegrass (the white based, tightly bunched look-alike) or dallisgrass (the coarser, perennial one). If you’re not positive you have crabgrass, identify it first. See the main crabgrass rescue article for identification help.
A Surfactant Is Not Optional
This is the most common reason quinclorac applications fail: the homeowner sprays it without a surfactant, sees no results in a week, and concludes the product doesn’t work.
A surfactant is a spray additive that helps the herbicide penetrate the waxy crabgrass leaf surface. The specific type quinclorac labels call for is methylated seed oil, or MSO, which in our world you’ll more commonly hear called simply a surfactant. Without it, quinclorac delivers at roughly half its rated efficacy. Every extension publication on quinclorac and the Drive XLR8 label itself say the same thing: the surfactant is part of the application, not an optional upgrade. A quart of generic MSO surfactant runs $15 to $20 and lasts a full season or more. Add it every time.
Rate: roughly 0.55 fl oz of surfactant per 1,000 sq ft, or per the quinclorac product label.
Timing: Earlier and Smaller Is Cheaper
Quinclorac works at every stage, but the kill is faster and cleaner on small plants. A crabgrass plant with 1 to 3 tillers (roughly the size of a quarter to a half dollar) will show reddening and twisting within 7 to 10 days and fully collapse within 2 to 3 weeks. A large multi-tiller mat from July or August will die, but it takes longer. Expect 3 to 4 weeks for full collapse, and a second application 3 weeks after the first may be needed.
Do not spray and then re-spray a week later because nothing looks different. That’s a wasted second application. Wait the full 3 weeks. Quinclorac is slow by design.
Air temperature: Quinclorac performs best between 70°F and 85°F. It slows down in cool weather and can stress warm-season turf when applied in extreme heat (95°F+). For summer applications, spray early morning, before 10 a.m., when air temperatures are still in the comfortable range and the turf isn’t heat stressed.
Rain: No rain for at least 4 to 6 hours after application. Rain washes off undelivered chemistry.
Mowing: Don’t mow for at least 24 hours before or after spraying. The plant needs leaf surface to absorb the herbicide.
Product Picks: 3 Tiers
All three tiers use the same chemistry at the same effective rate. The difference is formulation, brand, and how much measuring you want to do.
Tier 1 — Cheapest per application (~$15–25 per application on 5,000 sq ft)
Generic Quinclorac 75 DF + MSO surfactant
Quinclorac 75 DF is the dry flowable version, a wettable powder you dissolve in water in a tank sprayer. A 1 lb bottle runs about $80 up front, but the application rate is roughly 0.37 oz per 1,000 sq ft, which makes that bottle a multi-year supply for most home lawns and the lowest cost per application of the three options. You need a scale that reads to the tenth of a gram or a measuring spoon.
Total chemical cost per 5,000 sq ft application (quinclorac + surfactant): approximately $15 to $25.
Tier 2 — Middle (~$15–30 per application on 5,000 sq ft)
Generic liquid quinclorac 18.92% + MSO surfactant
The liquid formulation of the same chemistry, about $47 for a 32 oz bottle. Easier to measure, just fl oz marks, no scale needed. The rate is 0.5 to 1.45 fl oz per 1,000 sq ft (use the higher rate for denser infestations or larger plants). A bottle gives you 20 to 50 applications depending on rate, and the per-application cost is essentially the same as Tier 1.
This is the right choice for most homeowners. The liquid mixes easier and there’s less margin for measuring error than the dry flowable.
Total chemical cost per 5,000 sq ft application: approximately $15 to $30.
Tier 3 — Done-for-You (~$35–60 per application on 5,000 sq ft)
Q4 Plus combo concentrate (at DoMyOwn)
Q4 Plus by PBI-Gordon combines quinclorac (crabgrass) with 2,4-D and dicamba (broadleaf weeds like dandelion and clover) and sulfentrazone (yellow nutsedge, fast burn contact). One jug covers crabgrass, broadleaves, and sedge in a single pass.
A surfactant is still required for the quinclorac component to perform.
Rate is 1.5 to 2.2 fl oz per 1,000 sq ft. Higher cost per application than Tiers 1 and 2, but you’re paying for the combination. One application handles the mixed weed problem most lawns actually have in early summer. If you have crabgrass only, Tier 1 or Tier 2 wins on price.
The Actual Program
On my own zoysia in Georgia zone 8a, crabgrass is a manageable annual problem because split-rate prodiamine prevents about 90% of it before anything emerges. Here’s the full program. Unless you have a good reason to run it differently, this is what I have done:
October or November: Prodiamine 65 WDG at 0.37 oz per 1,000 sq ft. The fall application does double duty: it puts down the barrier that catches poa annua and the winter annuals germinating in fall, and its residual carries into the new year. Chemical cost on 8,000 sq ft: about $5.
Late February or early March: Second prodiamine application at the same rate. This is the one that shuts the door on the year’s crabgrass germination before soil temps hit 55°F, and it extends coverage through the spring and early summer window. Another $5.
May or June, only if escapes appear: Quinclorac + surfactant, spot sprayed on the visible plants only, not broadcast across the lawn. For a typical year, that’s 10 to 20 individual plants treated with a 1-gallon hand sprayer.
The whole annual program runs $10 to $15 in chemical for 8,000 sq ft. The reason it stays cheap is that the pre-emergent does almost all the work, and the fall app means the lawn is never unprotected. Quinclorac is the backup for the small percentage that escapes the barrier.
For anyone reading this in late May looking at a lawn full of crabgrass, the rescue cost is higher, typically $30 to $60 for a full application on 8,000 sq ft, but that’s still less than one visit from a lawn service. The lesson at the end of it is the same: put down prodiamine this fall and again in late winter, and you won’t need this article again.
3 Anti-Patterns
No surfactant. If you’ve already sprayed quinclorac without a surfactant and it didn’t seem to work, that’s almost certainly why. Re-spray with the surfactant this time. Don’t skip the adjuvant to save $15.
Wrong timing or wrong expectations. Spraying mature crabgrass in August and expecting it to be gone in a week is a setup for failure. Large plants take 3 to 4 weeks to fully collapse. The seeds are also close to set by mid-August, so even a successful kill doesn’t help next year the way an early-summer application would. Spray early and give the chemistry time to work.
Wrong identification. Goosegrass looks like crabgrass and quinclorac does not control it. If your spray didn’t work at all, no reddening, no twisting, nothing, go back and check the weed ID before re-spraying. Same product, same result.
Quick Reference
| Item | Detail |
|---|---|
| Active ingredient | Quinclorac |
| Surfactant required? | Yes — every application (MSO type) |
| Best timing | 1–3 tillers, early morning, 70–85°F |
| Kill timeline | 2–3 weeks small plants; 3–4 weeks large |
| Re-apply? | Only after 3 weeks, survivors only |
| Rain restriction | No rain 4–6 hours after spray |
| Mowing restriction | 24 hours before and after |
| Safe on | Bermuda, zoysia, bahia |
| NOT safe on | Centipede, St. Augustine |
Products Mentioned in This Article
- BASF Drive XLR8 (quinclorac, branded), 64 oz — ~$57 — Amazon
- Generic Quinclorac 75 DF, 1 lb — ~$80, multi-year supply — Amazon
- Generic liquid quinclorac 18.92%, 32 oz — ~$47 — Amazon
- MSO surfactant, 32 oz — ~$20 — Amazon
- Quali-Pro Prodiamine 65 WDG, 5 lb — ~$80, years of pre-emergent — Amazon
- Q4 Plus (quinclorac + 2,4-D + dicamba + sulfentrazone) — ~$50–65 — DoMyOwn
More retailer options will be added as we partner with additional suppliers.
For the full context on crabgrass identification and why prevention matters more than rescue, see the main crabgrass rescue article.
For timing mistakes that cost more than just the chemical, see Patience: When the Best Lawn Care Move Is No Move at All.
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