Try + Gerund or Infinitive
I tried sending her flowers.
Try + gerund I tried sending her flowers. Meaning: An experiment: I sent her flowers to see what will happen
Try + infinitive I tried to send her flowers.
Meaning: I tried to go through the procedure necessary to send flowers to her. The procedure might have been difficult.
Try + gerund means “perform the action of VERB to find out if it will accomplish some other purpose”.
The action of VERB is presumed to be accomplished. If the attempt succeeds, the purpose is accomplished: the smoke is cleared. If the attempt fails, the action is accomplished but the purpose is not: although the door is open, the smoke remains.
Try + infinitive means “attempt to accomplish the action of VERB”. The action is usually hard to do. I tried to open the door = I attempted to cause the door to become open. If the attempt succeeds, the action of VERB is accomplished: the door is open. If the attempt fails, the action is not accomplished: the door is still closed.