Becky,
Your article is clear and informative. I'd not heard of using H2O2 in watering. Love how you recycle the cups. Thank you for the great information.

Leslie - Thank you! I use diluted H2O2 all the time!

I want to add a note to consider for anyone reading this post:

I do NOT add the shredded cups to any edible plants in pots. I am still a bit concerned as to what is in styrofoam as it breaks down over time.