February. Cold water. Bright colors. Push lots of water. Grassy area.
Kirk is correct, but the same advice will allow you to hook up a few this time of the year.. However, the fight wouldn't be a long as in the winter, as they prefer cooler/colder water.
Like pike, chain pickerel are ambush predators who prefer to attack from the weeds...
I prefer to fish clear water with a solid wall of submerged vegetation where ya' can work a red/yellow bunny style streamer deep along this weed edge. However, in the summer in northwestern Louisiana I have also had success with damsel fly nymph patterns... I was targeting bream, but had a ball with pickerel!
Go slow and preferably not too shallow.
You'll have better luck in Caddo or other east Texas waters containing good populations of pickerel. See: http://www.gameandfishmag.com/fishing/fishing_tx_0205_01/