Posted: 01/08/2017 at 19:05
Strawberries will usually fruit well for 2 or 3 years. After that, you would usually renew them - either purchasing new ones or growing on the runners to replace the original plants.
From your photo, I'd suggest you have too many plants for the length and depth of your trough. You should also remove the runners - either discard completely if you want some fruit or use them to build up your Strawberry collection for next year.
Strawberries are quite greedy little plants - you don't appear to be giving them the space and depth they require to fruit well.