It's a good idea for a site, the pictures are gorgeous.
A real quick look and a few things already jump out. Here's a snip from
chard 'canary yellow'
As beautiful as the picture is, it's a mangelwurzel, (which is also a variety of Beta Vulgaris) not a chard.
I can't read the part of the text that is in the photo. I have to copy and paste the text into another programme to read it, and I'm far too lazy to do that unless the content shows promise. Making the text easy to read is probably going to be your best tool to capture and keep users. Keep in mind at approximately 20% of the English Language population are born with a language disability. More people develop them as they age due to vision loss or brain changes. I've seen studies suggesting less than 20% of native English speakers have a brain structure that is perfectly structured to understand the written word. Unfortunately for the rest of us, these people are the ones who make signs, advertizements, books, websites... etc. They sometimes forget that their audience may struggle with words. Taking the time to make things as easy to read as possible will draw more people to your site.
Privacy policy needs work. Some people still read these things, so keeping it short and sweet will help attract more people to sign up.
I'm with Burra about the chemicals. It doesn't interest me and I generally ignore sites that encourage its use. They always seem such a waste of money to me and I would much rather read about ways I can reduce monetary investment into my garden through creating my own soil, techniques for reducing watering needs, things like that. There are already hundreds of sites out there that talk about these things... it's boring. A site that talks about better ways, now that I find interesting. That's a site I would join and participate in.
As for posting on permies. We have very strict organic or better requirements for anything promoted on this site.