What do they tend to do on the porch? You could try re-creating that atmosphere and experience in a more convenient or desirable location! I'd create a hunt... put treats in different spots in your yard but not the porch! Do it regularly so their first instinct is to go search those spots. If the porch gets nice sunlight with good roost spots... then try to find another place where you can put roost spots or bathing spots in the sun.
The only way I could keep them off the patio and out of the garden was to put a 4 ft fence up. I had to put pieces of wire in a triangle on top of the 4x4's because my silly girls can jump that high. My back yard is fairly big, so I just cut it into sections - the chicken yard starts about 20-30 feet from the patio and about 60 feet across and about 70 feet deep. I only have a few chickens. The dogs and I have the rest. Works well for me. I do have to clip a wing to keep them in the chicken yard though. The fence is just pig wire on T bars, but this is also inside a 6 ft privacy fence around the whole yard. I do have a coop with a covered hardwire run that I can put the chickens in when I need to.
They’re so curious and funny. I always gently chase them off—they fly down... too high for a hen in the back portion. IDK... when they get on the porch, shoo them off. Our deck has two entrances—a low stairway in front and a high, steep one in back, which is where the birds are (except for the more venturesome ones). Hens sometimes get up on the low side, but rarely. If it were a problem I could put netting across the stairways. I think that would stop them. Not much help though, if you have a wide open porch.
