Time it right. Protect the trees you can’t replace.
Verbenone must be in place before mountain pine beetles fly. Answer a few questions for a best-guess window.
Your application plan
Choose your state and enter an elevation to see your estimated window.
Questions
How the estimate works
Best guess, not a forecast. Windows shift yearly with weather and site conditions.
The estimate starts with typical timing for your state and elevation, then adjusts for:
- Lower, sunnier sites → earlier.
- Higher, shaded, or dense stands → later.
- Warm spring → earlier; cool spring or snow → later.
- Lodgepole before ponderosa; high-elevation pines can run later.
Apply 7–16 days before expected flight. Protection lasts about 90–120 days.
Local check: 55–65°F days, fresh pitch tubes, or beetles in a trap → apply.
Typical windows by elevation
| Elevation | Put verbenone out |
|---|---|
| Below 5,000 ft | Late April – mid-May |
| 5,000–6,500 ft | Early – late May |
| 6,500–8,000 ft | Late May – mid-June |
| 8,000–9,500 ft | Mid-June – early July |
| Above 9,500 ft | Late June – mid-July |
Long-term typical windows, not a year-specific forecast. Northern states generally run later; Arizona and New Mexico earlier.
Where to put it
Verbenone pouches
- One pouch per tree, north/shaded side, 6–12 ft up.
- Use the reinforced strip; do not nail the center.
- Large tree: two pouches (6 ft and 12 ft).
- Stands: 20+ per acre, one every 25 ft around the perimeter.
- Not available in California.
SPLAT Verb paste
- Four dollops (17.5 g each), 7–10 ft up. One tube treats 10 trees.
- 6–12 in trees: four sides. Very large trees: 6–8 dollops.
- Stands: up to 2 tubes per acre, 10–20 trees.
- Available in California.
What if I miss the window?
Apply as soon as you can. Verbenone works best before the main flight, but it can still protect unattacked trees. Once a tree is under mass attack it won’t be saved — remove it and treat the healthy trees around it.
How long does protection last?
About 90–120 days (13–17 weeks), depending on temperature and weather. That usually covers one flight season. In hot, low-elevation areas, or where a second flight occurs, plan a second application.
How accurate is this estimate?
A best guess, not a prediction. Weather, elevation, and beetle populations can shift the window by weeks. Confirm with your state forestry agency, the USDA Forest Service, or a local entomologist.
Why does the date change from year to year?
Temperature drives beetle development. Warm springs move flight earlier; cool springs, snowpack, and drought push it later. A credible forestry report outranks this calculator.
Does this calculator work for other bark beetles?
No — mountain pine beetle only. Verbenone is only partly effective against other bark beetles; ask your state forestry agency or a local entomologist.
Ready to order?
Order early. Manufacturers often cut production before the season ends, and your application week can arrive before a late order does.
Buy Verbenone Pouches Buy SPLAT Verb
Questions about a large order or acreage? Call 512-282-3003.
