This is the golden rule, and I say this with the gentle authority of someone who has ruined a few good shirts. When you see that pollen, your first instinct is to scrub it off. Fight that instinct.
Pollen is made of tiny, barbed little particles. Think of them as microscopic grappling hooks. If you rub them with a wet cloth or your hand, you push those hooks deeper into the fibers of your clothes. That’s how you get a stain that won’t budge.
Instead, gently shake the garment outside. Or, take a piece of tape and dab it over the area to lift the loose powder. The less friction, the better. We are removing, not embedding.