Hi, I've looked through the guides, trying to find a collection of images of every plant in the game. I know there is over 500, but has anyone created an actual "Plant Guide"??

I don't know if there is a picture of all the 529 spieces of plants but there is several guides here:
Forums List » The Guides » Plant Tycoon Guide »
And these are the most complete, I think
[SPOILERS] Fan guides to Plant Tycoon
[MAJOR SPOILERS] Plant Tycoon Breeding Charts

Thanks Laurence, I've looked at both of those. I knew it was a long shot but thought I'ld ask anyways.

Maybe after I finish the game first time, I will make a guide.

with a pic of all the species? You'd be very courageous!!
But it would be nice!

It would also require careful preparation if the intent is to post it on the forums. A guide containing that many pictures could easily exceed the size limit for forum attachments. That's why people have only included pictures of each plant type and each flower type in their charts, and not every combination.