Hi Dave, I agree with everything above and especially Toni, I too like to shoot with the lens opened up into the light. There are a few other things that can improve an image of botanical subjects too. Using a reflector, one of the circular folding types is ideal, white will give a subtle fill, silver and white striped adds a little more light but still quite softly and silver can really fill in all the shadows, all can decrease the DR so its easier to get a good exposure for both highlights and shadows in one shot.
Using a folding circular diffuser made of transparent material instead of reflective can give the soft, even light that Alf mentions even on a bright sunny day and is a technique I use frequently for many botanical subjects. The reflectors and diffusers come in various sizes and will vary in price, Lastolite did and still (as far as I know) make excellent products, I've been using some of theirs for thirty years plus and they are still perfect, you can also get some excellent ones from Amazon etc that have a base diffusing disc and some zip on covers of reflective material, usually white, gold, black and silver, I have used some of these for a couple of years now and as long as you are gentle with the zips they work really well and cost not a lot and are great to experiment with. You can even make a few covers yourself from coloured or camouflaged materials to use as backgrounds when the real background is cluttered or distracting.