Grow "green manure" to keep soil from eroding, weeds from exploding and to add nutrients.
Keeping a worm farm is an easy project
Worm castings -- AKA poop -- add valuable nutrients to the soil and is easy to make. The hardest part is making the bin and that's not difficult.
The glistening cold of the Willamette Valley's first frost has ushered in the right time to clean up the garden.