The San Juan Worm is a highly controversial artificial lure that isn't really a fly, but you can use it while fly fishing. Some purists don't consider it a true fly because it does not have the characteristics of an insect, like six legs.
There have been arguments about this for decades as some call it a fly and some don't. Some say you should fish with it on fly rods, and some insist you should not. For some people, the term worm really sets them off and they can't see for any reason that it's appropriate to use a worm on a fly rod setup!
In this guide, we share some pro tips on how to fish one of these controversial San Juan worms and land a lot of fish regardless of the controversy. This is one 'fly' that can catch many different species like rainbow and brown trout, smallmouth bass, crappie, sunfish, perch, bluegill, rock bass, and even tailing carp.
These worms on a fly rod work from the San Juan river in New Mexico up to at least the streams of Michigan where they regularly catch many different species of fish on this simple lure.
Flyfishers can find live or dead worms adrift on river bottoms. San Juan worms are aquatic worms that are about 2" long but the lures range from 1-4 inches in length.
They’re simple to make. A length of chenille yarn is used over a variety of hooks and is usually weighted a bit to get it on the bottom.
How To Fish a San Juan Worm Like a Pro
Essentially, the San Juan Worm is one of the best lures you can use on a fly line to catch small freshwater fish species. All small fish in streams and lakes love tiny red worms. The problem is getting them on a hook and keeping them there. With a fly-tied worm on a fly-rod line, you don't have to worry about that at all. You can tie a worm lure in a few minutes and use it for a year if you're lucky.
To fish, the worm provides a bite-sized protein burst that doesn't take much energy to find or eat. Fish don't need to chase the worm down, it's there on the bottom waiting to be eaten. Like salmon eggs, it appears like the perfect food to prey on.
In nature, the small reddish worms drift with the freshwater current, especially after a rainstorm. If you're wondering whether fish bite after a hard rain that blows through in an hour or two, they definitely do! These worms have become a substantial part of many species' diets, all over the USA.
Springtime, as the water is warming and you're considering getting out there on the water for the first time, consider buying or making some of these small worm flies to try on the bottom of your favorite trout stream.
The San Juan worm fly pattern owes its origins to an old-timer who regularly fly-fished on New Mexico’s San Juan River. It is worth noting that the river which winds through Utah, Colorado, and New Mexico has an abundance of red bloodworms. Fly fishing anglers created a simple (and very fast to create) fly pattern they could use on their fly rods. The result was a tremendous number of fish being caught.
The reason these lures are especially effective after a rain is because the rivers swell up and cover once-dry banks, prompting the worms to crawl out into the water and drift with the current. Many fly fishers consider these worm flies a must-have for their freshwater fishing excursions. Once you try them, you probably will too.
Techniques for Fishing with a San Juan Worm
You can fish San Juan Worms the way you'd fish other wet flies. San Juan worm flies can be a challenge to get to stay on the river and fast-moving stream bottom because they are small and can catch some current. Slip shots and small beads added to the fly can help get them to stay on the bottom.
As a novice fly fisherman, one of the first things you are likely to learn involves tying a single San Juan fly onto a tippet. This is called a single rig and it's how most fly fishing is done.
Later, you may want to use a double-nymph rig. These are two worms on the same tippet and it can be highly effective as you are tempting fish to bite with double the ammunition. Two worms are often better than one!
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Many fly fishermen (women) will use a tandem rig for all of their fly fishing with San Juan Worms just because they get far more hookups this way than with a single worm.
There are a couple of drawbacks, like tangling up your line and casts being more difficult, but you should still learn this technique and employ it as fast as you can to catch more trout, bass, and other fish.
The steps below highlight the process of tying a tandem rig.
How To Create a Double Nymph Rig
Tie the leader to the fly line. The leader needs to sink when fly fishing with San Juan worms. Your leader should be around the 9 feet-long mark and gradually tapering down to where it connects with the tippet.
If you purchase a pre-made leader, attaching it to the floating fly line can be simply accomplished because the leader and the fly line both have loops. You can join them with a loop-to-loop linkage (a square not, essentially) and you are ready to go. If your leader does not have a prefab loop, you can just tie your leader to the loop in the fly line using a Nail Knot or a Perfection Loop Knot. Of the two, the latter is a bit easier and doesn't require a thin-diameter tube.
Join your leader to a tippet. Tippets should be around 2 feet in length and have a smaller diameter than the leader line. A tippet made of fluorocarbon line is perfect for this because the line is small, strong, and will sink.
You can use a barrel knot to join the tippet to your leader section. When connecting the tippet, ensure that you trim the ends of the tags since they can snag on the guides during casting your line.
Tie the top fly. The top fly in fly fishing jargon refers to the one that first goes on the tandem rig. It's best to choose a slightly heavier San Juan Worm as your top fly. A heavier top fly is better because it will assist in casting because the weight is in the right place. It will also cause less tangled lines.
A heavier top fly allows both of your worms to sink deeper to reach where the fish are feeding.
Finally, attach the worm to the tippet using an improved clinch knot. Remember to trim the end of the line to make sure it doesn't snag while casting or alert the fish that there is a line there.
Tie the second San Juan Worm onto a separate tippet section. Match the length of the second tippet to the first, and use the same line diameter and strength for both.
Join the second tippet to the top fly's hook at the bend, again using an improved clinch knot to lock it down. Cut the end of the line close to the knot.
Next, join the second tippet to your second smaller worm with an improved clinch knot and trip the end after ensuring the knot is well fastened.
Add weight to sink your rig to the bottom of the stream, river, or lake you're fishing. The amount of weight you will use will depend on the current. If there is no current, the top fly alone may have enough weight to sink the worms to the bottom. This will also result in the most natural presentation as they should not fall that fast.
If you do have some current, you will need to experiment with how much weight you need to add using putty and/or split shot.
Just as a side note, when you are tying your worms you may already know that the spot you'll fish them in has some current. You can use lead thread to wrap around the hook to add some more weight that won't be seen by the fish, but it will bulk up the worm a little bit and make it more appetizing for bigger fish.
Optional - add a bobber or other float as a strike indicator to your leader to let you know when a fish has taken the fly. This isn't crucial, and a lot of fly-fishing anglers refuse to use separate floats or bobbers at all. The thrill of using a fly line setup can be the minimalist approach to fishing and catching in nature and using as natural of a method as possible.
If you do choose to use one, you'll need to vary the distance along the leader that you place it to match the depth at which the fish are feeding. Using indicators of some kind is a good way to let you know instantly that you have a good bite. Without it, you have to judge by the line going out or fly line sinking whether you have a fish on the line or not.
How To Create a Dry Dropper Rig
A dry dropper rig is another effective way to fish a San Juan Worm. This method uses a dry fly that sits on the water surface and a heavier San Juan Worm that sinks down to the bottom or to whatever depth you choose. Below are the steps you can use to create this amazing rig.
Add a second tippet to the first one already attached to the leader. This second tippet should be about 2 feet in length or whatever depth you'd like to sink your worm to on or near the bottom.
Use an improved clinch knot to join the second tippet to the dry fly hook at the bend. The second tippet should be made of a fluorocarbon line because it has great sinking properties.
Add the heavier San Juan Worm to the second fluoro tippet. Use an improved clinch knot to keep the worm on the line. Ensure you cut the line tags. Add a split shot to increase the rig's weight if you need more in a fast-moving current. A fly fishing multi tool is ideal for securing split shot and cutting the tag end of the line.
Check to see if the distance from your dry fly to the heavier worm is about right to ensure you reach the depth you want to drop the worm.
Where Can I Buy San Juan Worms?
San Juan Worms for fly fishing are found online or in fishing shops across the USA. Almost everyone knows about their effectiveness and you shouldn't have a hard time finding some unless they're sold out. When you do find them, definitely get some extras because busy shops can and do sell out and you don't want to be left without them when you need them.
You can choose different sizes, shapes, and colors. The red and brown ones are recommended as a starting point. Choose some worms with different thickness to throw some variety into the mix as well. Worms generally are available in a size from 1-4 inches. You should have a bunch of 2-inch worms and a few of the other sizes just in case.
Fly fishing with San Juan Worms virtually assures you will catch some fish if the fish are there, even in the winter. Using different techniques like some of those mentioned above will put more tools in your toolbox and catch you more fish over time. If you don't know how to tie the knots we mentioned, start learning today, you can never know too many knots!
If you really get hopelessly into fly fishing, and it happens, take it upon yourself to learn as much as you can about other rigs and flies you can use on your favorite stream, lake,river or pond. Fly fishing in nature is a life-changing experience that you should enjoy as much as possible. Share your hobby with a friend or child to make it extra special!