Grannom Or Bust

Year after year the Grannom hatch never fails to frustrate me. The height of the hatch is a short lived affair which peaks normally around the beginning of April. The optimum time during the day seems to be between one o'clock and three o'clock and in that time there can be clouds of Grannom literally like a snowstorm one minute then a minute later they have all but disappeared.

The River Wye around Builth Wells

The Grannom sporadically hatching in 'clouds'

The Grannom Caddis Fly (Brachycentrus subnubilis)

The other problem is that when the trout get tuned on to them they become so preoccupied that nothing else will do and the difficulty then becomes working out at what stage the fish are taking them - ascending pupa, emerging caddis or adult. This can change instantly without any apparent reason why.
Last weekend on the River Wye there were times when the fish were very actively taking the flies either on the surface or just below, then without reason they would just stop feeding off the surface even though there were still many flies hatching.

This bruiser of a Chub gently sipped down my dry Grannom pattern and put a severe bend in my #3

I'm sure someone out there has a fly pattern that works very well during this hatch but I'm afraid it's one that isn't yet in my box. Sometimes I think I have it nailed and I will tie a fly that catches me a few fish then low and behold they decide it's no longer good enough and refuse it every time I put it over their head.

Although Grannom carry on hatching after this peak period I have found that the trout lose interest when they only emerge sparsely and quickly move on to something else. The reality is that unless you are able to fish the rivers daily it is hard to get out more than a couple of times during the peak period and therefore lessons are that much more difficult to learn.