The pilot reported that, during short final, the airplane encountered moderate turbulence, but he was able to maintain runway alignment and glide slope with constant power and flight control adjustments. During the landing roll, about 20 miles per hour, the tailwheel equipped airplane veered right. He applied full left aileron and rudder corrections, but the airplane continued to the right, exited the runway, impacted a garden post and came to rest upright in a row of trees. The airplane sustained substantial damage to the left wing. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation. The weather observation station located about 7 nautical miles from the accident site, about a minute after the accident, reported the wind was variable at 6 knots, gusting 15 knots. The pilot reported the wind was from 130º at 21 knots, gusting 30 knots. The airplane landed on runway 26. The pilot added that, after landing, the wind sock was discovered to be damaged, not indicating wind direction properly, was replaced days after the accident.