The following can all be used, you don't have to hit anything. Charging the Golden items won't make it faster.

Unlock Silver Hammer:
Use your Hammer 100 times

Unlock Golden Hammer:
Use the Silver Hammet 100 times

Unlock Golden Hoe:
Use you Silver Hoe 300 times

Unlock Silver Hoe:
Use your hoe 300 times

Unlock Silver Sickle:
Use the Sickle 350 times

Unlock Golden Sickle:
Use the Silver Sickle 350 times

Unlock Silver Axe:
Use your Axe 450 times

Unlock Golden Axe:
Use your Silver Axe 450 times

Unlock Golden Watering Can:
Use the Silver Watering Can 600 times

Unlock Silver Watering Can:
Use the Watering Can 600 times