In the East anyway, the Grannoms are the first major caddis hatch of the season and it's often a great one. This pattern is a lot of fun to fish and works well throughout all the phases of the hatch.
For a hook, Matt's going to use a Dai-Riki #305 in size 16. For thread, olive 6/0 Danville. Start your thread on the hook shank leaving a hook-eye length space behind the eye. Stop with your thread at about the hook point.
Matt uses crinkled green Zelon to imitate the egg sac of a female Grannom about to deposit her eggs. If you want to tie a male, go without it. Tie the Zelon in and wrap over the butt ends to form the underbody. Snip the trailing Zelon off close to resemble the egg sac.
For the abdomen, Matt uses natural gray Australian possum fur. Because you've already built up an underbody, create only a thin dubbing noodle. The abdomen should end about 2/3's of the way up the hook shank.
Snip a small amount of white straight Zelon free from the hank and tie it in to form an underwing. Even this small amount of Zelon adds a good bit of shimmer and gives the appearance of motion.
For the over-wing, snip a small clump of natural colored snowshoe rabbit free from the bottom of the foot. You may need to strip out some of the overly long guard hairs. Measure the clump to form a wing that extends just slightly beyond the underwing and egg sac. With a pinch wrap, secure the clump to the top of the hook shank and then take a few more wraps to bind it down well. Lift the fuzzy butt ends to vertical and, while being careful not to cut the thread, snip them off at a shallow angle. You can then take wraps to cover the butts and create a smooth foundation for the remainder of the fly.
Apply a light coating of sticky dubbing wax to about an inch and a half of your tying thread. Loon Products "High Tack Swax" is a really good choice. Starting with a modest clump of naturally colored hare's ear dubbing material, pull the clump apart numerous times to roughly align the fibers. While pulling out only small sheets at a time, touch dub them to your waxed tying thread. You really don't need much.
Starting at the wing, begin taking wraps to form an extremely bushy front end on the fly. Pull the fibers rearward to expose the eye and take a few wraps to hold the hairs' mask back.
You can then complete the fly with a 4 to 5 turn whip finish and cut or snip your tying thread free.
This pattern floats well and if it does get waterlogged, requires only a couple of false casts and a light dusting of Frogs Fanny to regain it's buoyancy. Dead-drifting it is great but don't be afraid to add a little skittery movement as well.