I have been a fan of worms in the garden and as part of my gardening team.
Worms ( red wigglers -Eisenia foetida ) are a great resource for Vermicompopsting or Worm Composting. The worms compost the food scraps , leaves, grass and orther compostables and create a “delicious” and powerful garden fuel. The castings are essentially worm manure and this manure is great with seeds or plants, brwed into a compost tea or use to top dress potted plants.
A pound of red wiggler works can be ordered for an estimated $22-40 depending on the source and location. A bin to keep the worms and their castings can be purchased or made-the investment here can be $5-100.
If you choose not to hire the worms you can buy the worm castings from several sources.
The other employees to “hire” are known as beneficial insects- These are “bugs” that will prey upon the pests in your garden. And can be purchased , or caught and relocated in your garden or lured into the neighborhood. I will focus ona few favorites and buying them.
Some Helper Insect information: http://www.organicgardening.com/learn-and-grow/top-10-beneficial-bugs-garden
In addition to worms the insects I have worked with are ladybugs ( ladybeetles) , praying mantis and green lacewings. They are helpful in the garden and they are attractive. Since I continually encounter them as I plant , weed and harvest – it is fun to know they are there-helpimng- and they are nice to look at.