While I fish 6 in. or larger grubs most of the year, I will switch to a 3 in. spade tail grub in winter. Spade tails have little inherent action, are fished on the bottom, and are good in current. I will fish them when the temperature is 36 degrees or below. They are best fished on ball head or small football head jigs with a 3(0) hook and 1/4 oz. weight or less.
The spade tail is fished to resemble a minnow feeding on the bottom. The best technique is to cast it out, let it settle to the bottom, and gently pull on the line. This causes the jig tail to rise above the jig head and resemble the feeding minnow. You can also gently shake the lure. This is a slow moving tactic made for cold water bass. The lure is especially good in river current. Cast it out, let it settle, and let the current provide the action to the lure.
An old but very good lure seldom used by today's fishermen!