Mayor de Blasio, who is 6-foot-5, gave his shorter predecessor Mike Bloomberg a real lift during a tree-planting ceremony Friday.

After speaking, de Blasio pulled out a step platform so Bloomberg, who is nearly a foot shorter, could reach the microphone at the podium.

“Bill, thank you,” Bloomberg joked. “This podium seems a little taller than I remember it.”

The duo made a rare joint appearance Friday to celebrate a milestone: The city has planted more than 1 million trees under an ambitious 2007 program launched by Bloomberg and singer Bette Midler.

De Blasio praised his predecessor as a “visionary” for launching the pro-environment city program.