feeding

I have always known when feeding to make sure the soil is wet not dry. so I would say after watering.

If its a liquid feed mixed in water, water with that - I just use Miracle Gro mixed up in 5 litres of water and water it on, always assuming the soil isn't completely dried out.

As Morgana says, feed when your earth is wet/damp. If it is dry the root hairs will take in nutrients at a strong rate, making growth fast. If you read Bamboo's blog on watering it gives you most rules to follow. Watering and feeding should take place in the early morning when the roots are cool, ready to receive food for daily growth.