Mystery Droplets on Car: Guttation or Honeydew?

Clear, water-soluble droplets on a car parked under trees are either:

• Guttation: Plant “sweat” from leaf hydathodes at night when soil is wet and humidity high.
• Honeydew: Excrement of sap-sucking insects (aphids, scale).

How to Tell

• Guttation: Uniform droplets on leaf margins, mostly morning.
• Honeydew: Sticky, often with sooty mold; random on leaves/bark.

Solution

Use a magnetic windshield cover. Controlling the source (tree insects or watering) is impractical.

Droplets on car—likely guttation from overwatered trees.