San Juan Worm

Sometimes the simplest fly is the one that saves the session. San Juan Worm is barely more than a piece of soft chenille or rubber on a hook, but it imitates a worm so convincingly that it often catches when more advanced patterns have gone quiet. It belongs in every put-and-take box as a reliable wildcard, especially when the water is coloured.

Simplicity is the strength

The point of San Juan Worm is the soft movement. The material bends and sways at the slightest current or strip, just like a real worm, and that is enough to trigger a rainbow trout. That the fly is so simple to tie and costs almost nothing only makes it more grateful to have along. When the fish have seen every usual fly, something as unexpected as a worm can be what fires the take.

When it comes into its own

San Juan Worm shines brightest in coloured water and after rain, when real worms wash into the water and the fish are locked onto just that food. It also works excellently as a “different” fly in the middle of the day when the standard patterns have stalled, and on freshly stocked fish that take something soft and mobile readily. Red is the original colour, but pink and natural brown are at least as useful.

How you fish it

Fish the worm slowly and deep. The most effective way is often to hang it under a fly indicator at a chosen depth and let it sit almost still, just as with a heavy nymph. Small, soft strips now and then are plenty, because it is the material’s own movement that does the work. When the indicator stops or is pulled under you make a calm strike. Without an indicator you creep the fly forward in very small steps near the bottom.

A fly to keep in reserve

San Juan Worm is seldom the fly you start with, but often the one you are glad to have when nothing else is happening. Treat it as a complement to nymph fishing and the parallel to worm as bait on the spinning side. More patterns to switch between you find under flies for rainbow trout.