Poplar dream meaning is explained below using 3 different sources. Each interpretation is shown with its source.

Interpretation 1 — Katherine Taylor Craig

To dream of a green poplar denotes fulfilled hopes, if withered it denotes disappointment (Gypsy). It was once held sacred to Hercules. Afterwards it symbolized the Holy Rood of the Christians (Bayley).
Source: The Fabric of Dream Author: Katherine Taylor Craig

Interpretation 2 — Stearn Robinson - Tom Corbett

Poplars in a dream are a warning against reckless companions who will try to tempt you mto foolishly dangerous adventures; be sensible—it’s better to be square than squalid.
Source: The Complete Guide to Interpreting Your Dreams Author: Stearn Robinson - Tom Corbett

Interpretation 3 — DreamForth

To dream of a poplar represents energy and strength.
Source: Dream Symbols and Analysis Author: DreamForth