Forget the lawnmower and pruners, any serious tog should be tooling up with their cameras and macro lenses when venturing into their back gardens.
It's a time to celebrate the return of vibrant colour to the world.
But keep in mind that flowers may look just as interesting when lit from the side or behind, than by full frontal light (sun or flash).
Maybe you want to concentrate on form, shape and pattern - black and white is perfect for this, as colour is a significant distraction in most images.
The foliage here (above and below) acts as a natural 'gobo'; that is, it partially blocks the light creating a delicate pattern of shadowing across the petals.
Partial desaturation can create a moodier look for your floral photography. Colour is hinted at, but doesn't dominate the image. A simple slide to the left on the saturation slider in Photoshop achieves this.
Getting in real close with a macro lens on your SLR (or lenses on compacts and bridging cameras) can offer a dramatically different perspective on a subject. A tripod (or other support) will be necessary to avoid motion blur caused by camera shake or even the gentlest breeze. Movement is more noticeable the closer you get to your subject.
Open up that aperture for a truly abstract view of the world.
Finally, a confression. None of these images were shot in my garden - or even outside. The subject was a vase of flowers on my kitchen window sill. Crop and angle hides many sins!