The fast and easy way to give an image a soft glow in Adobe Photoshop is to use the Gaussian Blur filter as you know it is not a destructive change. Select your background layer and use right click for this and convert into a smart object.
Then under the filter menu > Chose Blur > Chose Gaussian Blur Filter. Here you wanna make sure that the radius should be high and give to a large blur so let’s try an amount to 15 and click OK.
Gaussian blur filter in Adobe Photoshop
When you do it to your image has too many blur objects and obviously that not doing that you wanna to do, what you need is to give instruction to the Gaussian Blur filter to interact with the flower in a different way and you have a blend mode to do this.
So in the Layers panel, double-click on the blending options icon and that brings the blending options is here you can choose a blend mode for the filter to interact with the flower to give a nice soft glow, here one of the options that you can select is the screen. But you think that if it shows to much contrast in your image then you can use the opacity slider to just back of the little bit on that effect.
Create a soft glow with the Gaussian blur filter
There are also other blend modes that you might wanna try like if you want to build contrast in your image then you can move down either of the overlay blend modes or you can come down to soft light.
Soft light is always a little bit softer but the reason you don’t want to use it is will add so much distortion in your image. So you have to screw back to green blend mode and open the opacity to a little bit more and then click OK and don’t forget this is the smart object we are working with smart filters.