Many homeowners have trouble with sap dripping off their trees onto their cars and walkways. This sticky substance can be difficult to remove, accumulates dirt, and attracts flies and other annoying insects.
Most homeowners will be surprised to learn that this sticky liquid from trees isn’t sap at all. The sticky liquid oozing from the trees is known as honeydew, and despite the name, it has no relation to the fruit. Honeydew is the excrement of plant-sucking insects. Deciduous trees do not drip sap from their leaves. If you have “sap” dripping from your deciduous tree it is honeydew and is a telltale sign of an insect infestation.
Trees Susceptible to Sucking Insects:
Insect infestations that lead to honeydew are frequently found in hardwoods and conifers such as crepe myrtles, magnolias, ash, oaks, elms, and maples.
Signs to Look For
If your tree is dripping honeydew, that alone is a concrete sign that something is wrong with your tree; but there are other signs to look out for that can help you narrow down a diagnosis.
- Honeydew is a sticky sap-like substance that can coat anything beneath the tree. It may be annoying and a hassle but it typically won’t hurt your tree. The real issue comes from the fact that a fungus called sooty mold will begin to develop on the honeydew.
- Sooty Mold is a fungus that coats the leaves of your trees to the point where they can no longer absorb sunlight. That is to say that the process of photosynthesis is interrupted and the tree will not be able to produce the nutrients it needs for survival. If your trees and shrubs are turning black you most likely have a sooty mold problem caused by honeydew. If you see sooty mold on your understory plants, you can gently rinse it off with your garden hose.
What Causes Sap to Drip From Trees?
Sap-sucking pests that feed on the sap of trees cause damage and excrete honeydew.
How To Stop Your Tree From Dripping Sap
To keep honeydew and sooty mold from accumulating on your tree you must suppress the plant-sucking insects that create the sticky substance. To achieve this you have several options. We’ve got you covered – from DIY to professional help.
Prevention: Most insects are more likely to feed on stressed trees. Maintaining the health and vigor of your trees can help protect against an infestation of plant-sucking insects. You can maintain the health of your tree through routine pruning, bio-stimulant applications, and seasonal sprays.
Our Premier or Plus Canopy Protection Programs are exactly what you need to ensure your trees and shrubs are taken care of all year round. During Plant Health Care Inspections, our Environmental Specialists will treat ornamental trees as needed for sap-sucking pests.
RTEC Intensive Programs: For mature trees, our arborists recommend intensive treatments applied several times throughout the year, which work as both active and preventative control for major pests. Since these pests emerge annually, manage the population with repeated treatment.
Horticultural Oils: a natural alternative to traditional treatment methods is horticultural oil, which we can apply to your trees. So, it’s important to have a professional apply horticultural oil, as these products can often burn your plant if applied incorrectly.
Organic Control through Beneficial Insects: Aphids, lace bugs, and scale have many natural enemies. Try installing plants that attract these beneficial insects to help naturally combat the pests!
Lace Bug Natural Enemies:
- Jumping spiders
- Assassin bugs
- Lacewings larvae
- Ladybugs
Scale Natural Enemies:
- Lady beetles
- Predatory mites
- Small parasitic wasps
Aphid Natural Enemies:
- Lacewing larvae
- Ladybugs
Beware of DIY Treatments: Broad spectrum insecticides/oils you find at home improvement stores or online kill the insects’ natural predators. Using this type of “treatment” is a temporary solution. As a result, the infestation will come back with a vengeance because there are no natural predators left to fight them off. In conclusion, trust a Certified Arborist to develop the correct treatment for your property that takes into account beneficial insects.
If you have “sap” (honeydew) dripping from trees call us at 703-573-3029 or request an appointment online.
Is Your Tree Dripping Sap?
**NOTE: While this issue occurs nationwide, our current service area is limited to the Washington, DC Metropolitan Area.