This is done using Elements 11, but can be easily performed in Photoshop CS versions.
Before we begin, this image needs to be cropped to look more like a macro shot. Select the Crop tool and head to the list of preset sizes, and change it from No Restrictions to 8 x 10in.
Crop the image down and aim to leave a slight gap between the top and bottom of the flower. Place the centre point of the crop box over the middle of the flower. Click on the green tick to apply the crop.
Before any edits are made to the image, make a copy of your image’s layer by pressing Cmd/Ctrl+J. Layer 1 should now appear in the Layers panel above Background.
Select the Magic Wand tool (W) from the Toolbar (in Elements 11 this is hidden under the Quick Selection tool). In the tool’s options set the Tolerance amount to 50 and deselect the Contiguous box, so that the maximum number of pixels is selected.
With the Magic Wand tool ready, click once on the flower to select it. A selection should appear over the whole flower. but some parts may be left out. Hold Shift and click on those areas of the flower that were left out of the initial selection, until the entire flower is selected.
Remove areas of the selection on parts other than the flower, for example the background, by ticking the Contiguous box. Increase the Tolerance amount to 80 to make this easier, and then click over these areas holding Opt/Alt to remove them from the selection.
Press Cmd/Ctrl+J to copy and paste the flower onto a separate layer. Click on the duplicated background layer (Layer 1) and go to Filter>Blur>Gaussian Blur. Set Radius to 45 pixels to blur the areas behind the flower, and hit OK to apply the filter.
Select the flower’s layer (Layer 2) and make a direct copy of it by pressing Cmd/Ctrl+J. This new duplicate will contain the in-focus flower. Click on the Add Layer Mask button in the Layers panel, and then press Cmd/Ctrl+I to invert it from white to black.
To help add depth to the effect, click back on Layer 2 and go to the Gaussian Blur filter again. Reduce the Amount slider to 15px to make it not as blurry as the background areas of the image, and hit OK.
Select the Eraser tool (E) and set your Foreground colour to black by clicking on the front swatch at the bottom of the tools. Set the tool’s Opacity to 100%, Size to 250px and choose a soft edge brush. Click on the layer mask on Layer 2 Copy to highlight it.
Work out from the centre of the flower with the Eraser tool removing the blurry areas to reveal the in-focus flower underneath. The layer mask in the Layers panel should represent changes made with white. Lower the Opacity of the Eraser tool to 30% for a soft blur for areas surrounding the centre.
The background colours can be reduced to draw more attention to the flower. Cmd/Ctrl-click over the flower’s layer thumbnail to activate it as a selection. Go to Select>Inverse (Cmd/Ctrl+Shift+I) to flip the area around, so that the background is selected.
With the selection showing around the background go to Layer>New Adjustment Layer>Hue/Saturation. Hit OK in the pop-up box and then reduce the Saturation slider to -25. The green colours should reduce in strength making the reds seem stronger.