If you live in humid conditions, you'll probably have to wash them more often.

In terms of how to wash them, he suggested a regular "less harsh, frequent wash" and an "aggressive deep clean" every so often. He added, "Folks in more humid climates will need to wash towels more frequently due to mildew concerns."

For frequent washing (towels and bedding): 

"Pre-treat stains as needed, wash on a normal setting with cool or warm water, use your favorite detergent and rinse product (no fabric softener, please), and dry low and slow. 

"Soak in hot water and powdered oxygen bleach overnight and then wash with a sheets/bedding  towels cycle (these are usually long and use high temperature) with detergent and a rinse product (a sanitizer would be good here too), and dry low and slow." 

"You can add powdered laundry boosters or powdered oxygen bleach to the drum of the machine during both processes to boost the cleaning and whitening power of your detergent."