The pro way to attract woodpeckers is with grease. A suet block will work a bit but there are more effective (and way cheaper) weapons. Grab a chunk of thin log about 2.5 inches in diameter and about 16 inches long. Bore 6-8 1 inch holes all over the log and put a screw eye in one end so you can suspend it from a branch. Cook up a batch of bacon on lowish heat and let the leftover fat cool, then put it in those 1 inch holes. mmmm tasty and there are all sorts of birds that will appreciate this. Having to eat bacon regularly is a harsh sacrifice to have to make but some folks are willing to do it. Alternately, visit your friendly butcher and get (hopefully for free) some pork fat that he will be trimming away and throwing away (beef fat also works but is slower to render down). You can even cheat and just spread the fat on a tree trunk but in spring this will start attracting raccoons and other wildlife.
27th Street 
The pro way to attract woodpeckers is with grease. A suet block will work a bit but there are more effective (and way cheaper) weapons. Grab a chunk of thin log about 2.5 inches in diameter and about 16 inches long. Bore 6-8 1 inch holes all over the log and put a screw eye in one end so you can suspend it from a branch. Cook up a batch of bacon on lowish heat and let the leftover fat cool, then put it in those 1 inch holes. mmmm tasty and there are all sorts of birds that will appreciate this. Having to eat bacon regularly is a harsh sacrifice to have to make but some folks are willing to do it. Alternately, visit your friendly butcher and get (hopefully for free) some pork fat that he will be trimming away and throwing away (beef fat also works but is slower to render down). You can even cheat and just spread the fat on a tree trunk but in spring this will start attracting raccoons and other wildlife.