Sticky sap dripping from a tulip poplar onto a driveway, deck, or parked car in Richmond, KY is almost always tuliptree scale, a soft-bodied insect that feeds on the tree’s sap and excretes the sugary honeydew raining down below it.
What’s Actually Causing the Sticky Sap Under My Tulip Poplar?
Tuliptree scale insects feed on branch sap and excrete honeydew, a sugary liquid that coats leaves, cars, and pavement below infested tulip poplars.
Tulip poplar (yellow poplar) is Kentucky’s state tree and one of the most common large shade trees in Richmond yards and street plantings, which is exactly why this scale shows up so often locally. As the honeydew builds up on leaves and whatever is parked or sitting underneath, black sooty mold fungus grows on top of it — that’s the dark, sooty-looking film homeowners usually notice before they ever spot the insect itself. Magnolia and other poplar species can host the same scale, but in Madison County it’s tulip poplar that brings in the most calls.
How Do I Know It’s Tuliptree Scale and Not Something Else?
Look for pea-sized, brown-to-orange bumps clustered on twigs and small branches — that’s the scale itself, not tree bark or a disease spot.
Mature female scales swell into a rounded, warty-looking bump on the underside of small branches, usually most visible from mid-summer on. They don’t move once settled, which separates them from aphids clustering on new growth or the flying adults of spotted lanternfly, another honeydew-producing pest now confirmed in Kentucky. A heavy infestation can make an entire limb look bumpy and discolored at a glance. If you’re not sure which pest you’re looking at, our tree disease and pest diagnosis visit rules it out before any treatment gets recommended.
What Does It Typically Cost to Treat Tuliptree Scale in Richmond, KY?
Treating tuliptree scale on a mature yard tree typically runs $150 to $400 per visit, depending on tree size and access.
That range is typical, not a quote — a large, mature tulip poplar with full canopy coverage costs more to treat thoroughly than a young tree, and multi-year infestations sometimes need a repeat visit the following season. Dormant oil applied to overwintering nymphs is usually the lower-cost option; a systemic insecticide timed to crawler emergence costs more but reaches scale higher in the canopy that a spray can’t fully cover. Thinning a dense canopy during a routine tree trimming and pruning visit also improves airflow and sun penetration, which makes conditions less favorable for scale to build up in the first place.
When Is the Best Time to Treat Tuliptree Scale?
Late winter dormant-oil applications and early-summer crawler-stage treatments are the two effective windows — spraying at the wrong time wastes money.
According to the University of Kentucky Department of Entomology (ENTFACT-435, Tuliptree Scale), dormant oil applied in late winter targets the overwintering immature scales before they harden, while a targeted insecticide applied as crawlers emerge — typically around early summer in Central Kentucky — catches the mobile stage before it settles and becomes harder to reach. Treating outside those windows, once scales have hardened into their protective covering, is far less effective for the money.
Common Questions
Will tuliptree scale kill my tree?
Rarely outright on an established, otherwise healthy tulip poplar — it mainly stresses the tree over repeated seasons, especially combined with drought. A young or already-declining tree is at more real risk and is worth treating sooner rather than later.
Is the sticky sap harmful to my car or deck?
The honeydew itself isn’t toxic, but it stains and the black sooty mold that grows on it is unsightly and can be a hassle to wash off pavement, furniture, and vehicles parked underneath.
Can I treat tuliptree scale myself?
A small tree within reach of a garden sprayer is a reasonable DIY dormant-oil job. A large, mature tulip poplar usually needs a bucket truck or sprayer with real reach to cover the upper canopy, which is where most of the scale actually lives.
Related: Tree Disease & Pest Diagnosis | Tree Trimming & Pruning
Not sure if the sticky drip under your tulip poplar is tuliptree scale or something else? Get a free estimate or call or text (859) 310-1209.
Source: University of Kentucky Department of Entomology, Tuliptree Scale (ENTFACT-435).
Last updated: September 28, 2026