How do you use harvester in farm town?

its simple, make sure u have fuel, then just press "x4" on the normal harvest icon.

click on the seeder (the machine itself) and goto plant seeds

You can buy in the shops seeders, harvesters, plowers, fishing boats and tree shakers. There are different types of these including: X2, X4, X6, X8...

You purchase the tools which have to be purchased in order i.e. 3 x 3; 4 x 4; 5 x 5, etc. Once they are purchased and placed on your farm, you can move them to your storage to utilize all the space...

Go to the map in the bottom right hand corner and go to the Retail Office. It will automatically pop up a screen and you can choose to upgrade your farm.