Tulip poplar sap

Asked June 18, 2018, 8:07 AM EDT

This year our trees are “raining” sap in in greater quantity than I recall from past years. Is this condition being experienced around the region or is this localized? What conditions are contributing to this? How long should we expect to experience this sap deluge? Any insight you can offer will be appreciated. Thanks. Jon

Montgomery County Maryland

1 Response

Jon,
The sap you're experiencing from the tulip poplars is honeydew. It is a byproduct of aphids feeding on the sap of the young succulent new leaves of the tree. The recent heavy rains have favored the development of lots of tender new growth on the trees -- just the kind that aphids like to feed on.

When aphid populations are high, typically their natural predators (beneficial insects) eventually catch up to them and reduce their populations naturally. You can read more about this "biocontrol" on our website: https://extension.umd.edu/hgic/aphids-trees-and-shrubs

ckc