I run a bilingual website. It has operated this way for seven years now.
My approach: except for FAQs, etc., different content - not translation of the same articles, but different articles in each language.
If you use some type of CMS, a good way to do it is: five most recent articles / posts in each language on front page, in two parallel columns. Then the possibility for readers to access the chronological list of posts/articles on a separate page either in one language only, or in both languages.
I feel that having a common welcome page for both languages (what would be index.html or like that), but then the option to bookmark a separate welcome page for one language only if one prefers, is a good option.
Or - if the site is garden.ca, which I see in your signature - why not to have one of your three columns titled "French"? Whar I described above is my approach for one specific website, which was created bilingual from scratch - there are other possible ways of doing it.
But your three current columns seem well-chosen, and I would be hesitant about removing one of them.
But I would try to find a way at least to have a box with some French content on front page (and then a separate page with French only), in order to show from start to French-speaking visitors that they will find French language material as well.
Good luck!