Wood Pigeon - what age to let free?

Hi My wood pigeon has been hand reared for 2 and half weeks now he was approx 5 or 6 days old when I got hi,. I have fed him on porridge and readybrek by a syringe on the advice of a racing pigeon fancier. He is thriving and learning to fly a little. I am struggling a bit to get him to eat seed and have been feeding him half porridge and half soaked seeds of a mixture of wheat and two other things locally called 'thirds' from a local bird feed supplier.

We have had him in the garden and he pecks the ground but not the seed yet. Will try and keep encouraging him.

Any advice would be gratefully received. I will be back online tomo as just moved house.

Best regards Sue Lawson