Clemson Cooperative Extension Service
Especially their Home Garden Information Center
They publish fact sheets on topics from home garden planning, weed control, pest management, canning and more.
Their Gardener's Toolbox is an amazing resource for plant species identificiation, care information and garden planning.
The JC Raulston Arboretum at NC State hosts free Zoom classes on topics from highlighted species to monthly garden maintenance check lists.
When searching Google for any gardening related topic: I suggest adding .edu, .gov, .pdf to your search.
Doing so gives you a better chance of finding articles and resources hosted by Agricultural Extensions, Government Agencies and Universities.
This can help weeds out the ad farm bot-generated blogs that repeat the same generic (usually incorrect) “garden advice”.
One of the best resources is your state's Cooperative Agricultural Extensions.
“Extension provides non-formal education and learning activities to people throughout the country — to farmers and other residents of rural communities as well as to people living in urban areas.”
“All universities engage in research and teaching, but the nation's more than 100 land-grant colleges and universities have a third, critical mission — extension. Through extension, land-grant colleges and universities bring vital, practical information to agricultural producers, small business owners, consumers, families, and young people.”
“Cooperative Extension is a national network of 35,000 professionals from 112 Universities with presence in every county, borough, parish, and territory that empower communities of all types and sizes through educational programs, resources, and research-based information to help realize their potential and improve quality of life.”
You can contact your local extension with questions, access free and paid services, attend classes and more.
Many of channels you see are there to shill a product to you, make entertainment with no substance or portray themselves as experts.
That said, here are some channels I recommend who creators are more interested in relaying information and advice.
https://www.youtube.com/@JimPutnam
Located in urban Raleigh, NC USDA 7A
That makes him a great resource for SC gardeners as our growing conditions are similar.
Lots of “no-frills” practical gardening advice and a large catalog of in-depth videos.
He has another channel for highlighting specific plants called Garden Plants with Jim Putnam
https://www.youtube.com/@MIgardener
Located in Michigan, so their growing season is a bit different than ours.
Good general gardening information and is also runs a seed farm that sells a good variety of quality seed varieties.
NCSU Extension's YouTube Channel
https://www.youtube.com/@jcraulstonarb
The JCRA Youtube channel posts recordings of their free Zoom classes and discussion.
Highly recommended.
https://www.youtube.com/@offgridcurtisstone
His early videos on “urban farming” for profit are very informative and his later content is too.
At some point he started sharing some of his views on politics and society in general.
I felt it took something way from the gardening content.
That said, I'd still recommend his channel as he does cover a lot of topics thoroughly with practical advice.