Here is a collection of blogs maintained by seed companies. Unlike in the Seed Snatcher search engine I will not edit out seed companies based on them taking the Safe Seed Pledge. However, I will only list stand alone blogs. That is blogs not attached to a company's website. The seed blogs listed here are only for information and/or research purposes and should not be construed as an endorsement of their business or seed suppliers.
Renee's Garden Seeds. Blog by Renee's Garden
TM Seeds. Blog by Thompson & Morgan US/Canada
Growing Ideas. Blog by Johnny's Selected Seeds
I will add more as I come across them.