Hey skyisred,
Welcome to TMU’s forum 
! Thanks for your question.
Congrats on your son’s new mattress shopping journey ! He must be quite excited to be moving to his first “grown up” bed; what size will he be getting? Regarding potential mold issues, does your home have humidity concerns? Keep in mind that many materials can be susceptible to mold, given the right environmental conditions for its encouragement. Latex in itself is considered to be mold resistant and does not encourage mold growth; however, damp encasements in combination with higher humidity could promote mold development. In other words, if mold spores are present and have nutrition and water available, it will grow regardless of whether latex is the host or some other material.
Naturepedic’s Verse Organic Kids Mattress features comfort layers of organic cotton over a 7" pocket coil support core and is rated as a firm support mattress. Naturpedic also describes the comfort feel as “slightly firmer”. Whether your son perceives the comfort feel of the mattress to be too firm will depend more on his height, weight, and body profile, resulting in how deeply he sinks into the mattress. For others who may be following your research, here is a quote from the Phoenix post you reference regarding mattress firmness for kids:
“Generally, for growing children, you’d want something more in the “medium” to “medium-firm” range, due to their epiphyseal plate and postural formation, but other than this I would make your final choice based your preferences of materials, which one you believe would be most suitable for your children, your conversations with each manufacturer, the options you have to change the comfort level of the mattress when your children get older, their body matures and develops, and their needs and preferences change (by adding a topper, flipping the mattress, or changing the layering), your budget, and finally based on “best judgement” and which one you are “leaning towards” most strongly.”
What is your son’s current height and weight? Generally speaking, during the “growth spurt” years between the ages of 8- 16, a child’s height and weight can double as they approach adulthood, with their body’s comfort and support needs continually developing along the way. A medium firmness mattress is often recommended for children, as it offers enough of a comfort surface combined with proper support of their developing bodies. During the teen years, a separate mattress topper can be added to provide more comfort, should your son’s preferences change.
[quote]Anyone tested the Verse? Is it really firm? Too firm for a soon 6yr old? He is pretty large for his age and I really have no idea if he’s going to end up a large adult, or slow down at some point.
We are in Canada, BC[/quote]
Hopefully, someone with Verse experience will drop in and share their experience with you, skyisred. Good luck with your research and let us know what mattress you decide on for your son.
Sensei