Pilot reported flight control abnormality after takeoff due to an article of clothing that had wrapped around the aircraft's tail.

Narrative

I flew my Belite Ultracub with the intention of making a few landings and takeoffs for proficiency. This is an E-AB aircraft of conventional high wing design with a tailwheel and a single seat; powered by a 1/2 VW. The cockpit has a windscreen in front and an enclosed area behind the seat with a small shelf for storage; but is completely open to the sides.Wind was light at about 5 kts. directly across Runway XY-XX. I chose XX because it has lower terrain on initial climb. The first takeoff and climb was completely normal; which for this aircraft means a climb rate of about 300 fpm. The subsequent approach and landing was also normal; with a forward slip on short final to steepen the approach; although in retrospect elevator authority in the flare was less than normal.After a full stop about 1/3 of the way down the runway; I took off again. Acceleration and liftoff seemed normal; but it was quickly apparent that something was wrong; with the initial indication being a climb rate between 0 and 100 fpm; although engine rpm was nominal for climb. I was fortunate in my choice of Runway XX; because I actually needed the clearway beyond the runway; being below the tops of trees to my left and right. A departure on XY would have certainly resulted in a collision with trees. Having gained perhaps 300 ft. of altitude; I made a gentle left turn for a close-in; low; left downwind for Runway XX; still at full power and climbing very slowly. The control stick was moving irregularly fore and aft; and a lot of back pressure was required to keep the nose up. The airspeed was quite unstable; which doubtless reflects my imprecise control of the pitch attitude. The aircraft's handling characteristics I would describe as challenging and clearly abnormal; but not really alarming. I made a fairly normal approach and landing on XX; though my ability to flare was less than normal and touchdown had a higher sink rate than desired as a result.As I taxied back to the hangar; I was met by a Local Mechanic who had observed the flight and came out to meet me on his scooter. I stopped next to him and he removed a jacket that was wrapped completely around the left empennage and elevator; entangled in the flying wires that support the tail structure. Seeing the plane from the ground; he had initially thought that the yellow fabric covering on the tail had ripped and was flapping in the breeze; and was concerned for the safety of the flight. The jacket was also yellow.The jacket had clearly been on the storage shelf behind the seat; though I had not noticed it on preflight. One would expect the airflow in flight to keep items pressed back against the bulkhead; not to exit through the door opening forward of the shelf. This would have been the case; except for my forward slip on final; which resulted in a crossflow through the cockpit.Lesson learned: The storage shelf must be verified to be totally clear on preflight! If I had chosen the opposite runway for departure; this would have been [a much worse] report.