Sorry but NGA does not have anything like what you are looking for. It's a gardening site where gardeners from around the world can participate in various forums, ask gardening questions and find articles and web tools for their garden interest. It also contains a huge plant database that members can contribute plant growing details and personal photos.
From our About page:
On the Garden.org website, gardeners can access a vast and rich resource of articles, information, community features, gardening research, software tools, and all manner of gardening content to find how to grow all kinds of plants, identify and control pests and diseases, or figure out what kind of weeds are sprouting in the garden.
At the center of the site is our large and complete plant database, which contains 789,871 plants and 830,692 photos. This interactive feature enables NGA community members to share photos and information about the plants they are interested in, and facilitates discussion centered around those contributions. Detailed information, such as parentage, bloom color, hardiness, etc., is present for most plants in the database, and a powerful search engine lets visitors find plants by querying for these specific characteristics.
Daily ideas and expert articles, and an audio podcast are posted to the site, and a weekly email newsletter containing all the best content from the previous week, along with the best photos posted to the database, and much more, is sent out to the members every weekend.
The site also features numerous web tools for gardeners, including a useful gardening planting calendar, reviews of gardening companies, and dozens of highly active forums are available for gardening inspirations and conversation.
Online membership to the NGA is free and available to all.