We're all out - almost!

Our camellias are now in full bloom, making a wonderful display at the far end of the front garden, a pretty contrast to the yellow primroses and tete a tete near the drive. 
I was taking a close look at the flowers coming out in the back garden, and noticed to my disappointment that my once healthy wallflowers have disappeared! Who is guilty - slugs, snails, or birds??
Apart from that, I am thinking that we need a small tree - right in the middle! An apple tree perhaps, as we do not have any fruit trees. It would need to be carefully pruned so as to keep a neat, small shape and enhance the garden rather than dominate it!