How to Get Rid of Bagworms on Trees in Kansas (The Mid June Window)
Lawrence and Topeka homeowners search this every June. The larvae are only exposed for about three weeks. Miss that window and you are spraying a sealed bag.
Search Console is already sending “how to get rid of bagworms on trees” to this site. The older post on timing still ranks on page 7. This page answers the job itself: what to do in Lawrence and Topeka, and when it is already too late.
The only window that works
Bagworms live inside a silk bag covered in bits of the plant they are eating. Once that bag is thick, insecticide on the outside does not reach the insect. Treatment has to hit the larvae in the first weeks after hatch, while they are still feeding in the open.
In northeast Kansas that hatch is mid June. Some years late May. Some years the first week of July after a cold spring. If you are guessing in August, you already missed it.
We wrote the calendar in more detail here: bagworm treatment timing in Kansas.
What we actually do on a job
We look at the plant first. Arborvitae, eastern redcedar, and juniper are the usual hosts. A maple with a few bags is a different problem than a windbreak that is already brown on the south side.
If it is still June and the larvae are small, we spray. If the bags are already sealed, we tell you that on site and we do not sell you a spray that will not work. Hand-picking still helps on plants you can reach. On a tall cedar row it does not.
Dead or half-dead evergreens after two seasons of stripping often need tree removal rather than another round of product. We will say so before anyone starts.
Lawrence and Topeka yards
Bagworm pressure is worse on south and west exposures and on plants that were already dry. A Topeka windbreak and a Lawrence privacy screen fail the same way: the bags show up one June, nobody sprays, and the brown patches show the next spring.
If you want the plant looked at rather than a product dumped on it, that is a tree health diagnosis visit. Estimates are free. You do not need to be home.
Work is Monday to Friday, 8:00 AM to 5:00 PM. Call (785) 371-4859.
Related: tree trimming in Lawrence and Topeka tree service.
Questions this article usually raises
When do you spray bagworms in Kansas?
Mid June in Lawrence and Topeka, give or take a week. That is when the eggs have hatched and the larvae are still small. August spray jobs on sealed bags do not work.
Can I pick the bags off by hand?
Yes, on a small shrub or a young arborvitae you can reach. Each bag is next year's egg mass if it is a female. On a 20-foot cedar row you will miss most of them, which is why we spray in the hatch window instead.
Will bagworms kill the tree?
One year of light feeding usually does not. Repeated stripping on arborvitae, cedar, and juniper will. Those species do not put out new foliage on old wood the way a maple does.
Services in this article
Relevant service areas
Keep reading
- Pine Wilt Is Why Your Windbreak Has Gaps Pine wilt kills a mature Scots pine in a single season and there is no cure once it takes hold. What Kansas landowners can do about the trees still standing.
- Seven Signs a Tree Is About to Fail What to look at when deciding whether a tree is a hazard, and which warning signs are urgent versus worth watching.
- Emerald Ash Borer in Douglas and Shawnee County: Treat or Remove? EAB has been in Kansas since 2012 and is established across the northeast counties. How to tell if your ash is infested, and the point where treatment stops being worth the money.