What are some ways I can grow my 401k that don't include investing in the stock market?

As long as you're working at your current company, you're limited to the investment options offered within the plan, so unless there is a non-stock investment option (I'm lumping bond funds into the term "stock market," as those also fluctuate in value), such as a fixed annuity product, your only option for growth would simply be to save more.

With employer-sponsored 401ks, the investment options are quite limited. 

For more investment options, you can look into setting up an IRA. Since it is not tied to your employer, you can do research and select a plan provider with the best investment options. Don't forget to check the costs and fees with each provider you talk to.

Another option is self-directed IRA, which gives the plan owner the ability to take control and invest in almost any legally available investment options. To successfully invest your retirement savings, however, you need to do your research and study the options available.