Mask out the blossom and using a No. 6 Round brush paint a watery wash over the whole area using cobalt blue to suggest sky and cadmium yellow pale to suggest leafy areas.
When this is dry, paint a layer of leaves using a No. 4 Round brush in a medium spring green colour, leaving the yellow showing through in places.
Let this layer dry then paint another layer of leaves using a dark spring green.
Leave to dry then rub off the masking fluid and paint the blossom using light red, which gives a natural looking pink colour. The blossom should be painted in layers with a No. 4 Round brush working from light to dark and can be worked wet into wet or wet onto dry or a combination of the two techniques.