Your Greenspeed has been built with many quality products to make maintenance a fairly easy task.
The chain should be kept lubricated with a chain lube that suits your particular climate/conditions (Greenspeed recommends Prolink, www.progoldmfr.com); your local bike shop should know the ideal lube for your particular requirements. If it ever becomes dry and squeaks, it is crying out for lube, and will make the trike harder to push!
The steering ball joints are nylon and don’t require lubrication.
The kingpins are fitted with grease nipples, (see picture, below) but should only require greasing once a year. At the same time you lubricate the kingpins, turn your trike upside down and add a few drops of oil to the handle bar pivot.
Check your tyre pressure before each ride and you will find that your trike will be easier to push. Try experimenting with pressures, lower tyre pressure will give a more comfortable ride and higher speed on rough roads, but higher tyre pressure will make it roll easier on smooth roads. There is usually a good compromise at between 70-80psi.
Front hubs, be it disc or drum, have sealed bearings that don’t require lubrication. If you have any problems with the hubs, please contact Greenspeed.