I am going to keep this simple- there is only one truly important thing to remember when you are taking a wildflower portrait- background. There are a few other things to be aware of certainly- how pretty the flower is, how nice the light is, is it windy, are you rushed- but all of them are inferior to the background. Nothing kills a flower portrait quicker than a bad background.
So how do you assure a good background? The first thing you do is to preview it in your viewfinder or on your LCD. Take a test shot and see if there is anything distracting in the background. If you use the depth of field preview button be sure to give your eye 30 seconds or so to accommodate to the sudden darkness. Things will appear more clearly after 30 seconds.
The second thing you do to assure a good background is to try to pick an angle that puts the closest part of the background at least a couple of feet away. If the background is closer than 2 feet from your subject than it will not be out of focus (that beautiful soft, poster board background) no matter what f-stop you use. I am forever trying to find a good subject with a background that is far away. In fact, I almost always look at the background first and then find the flower and angle that lets me use that background.
Third thing you can do is use your longest lens you can to get the shot you want. The longer the lens the narrower the viewing perspective and with a narrow viewing perspective the easier it is to pick a pleasing background. My flower portrait lens of choice is my Nikon 200mm macro lens- it allows me to get as close as I want and it has such a narrow angle of view that I can practically pick any background I want.
And background is all you will ever want- great background allows a great photo.
And I suspect you were on the ground as part of the foreground.
I am often on the ground when I am photographing- sometimes it is even on purpose. Here’s a story for you. Twenty years ago one of the pros I thought with told a funny story of photographing tiny mushrooms in his front yard of his new home in North Carolina. Sprawled out to get ultra close and trying not to move he succeeded to get some stunning photos. Later that day, his wife was at a get acquainted neighborhood ladies coffee when she was approached with sympathy and concern. “Dear, if you need to talk or need any help with your husband we are here for you.” Inquiring what they were talking about the woman said “It’s okay dear, we saw him passed out on your lawn this morning. You have nothing to hide.” As the story was told, the neighbors never did believe the photography story. See you soon, Bob!