This is Hypericum x hidcoteense 'Hidcote' from the Hypericaceae family.  Commonly known as 'St Johns wort 'Hidcote', this evergreen shrub with bright yellow flowers and orange anthers flowers from late summer till autumn.  It's ideal for informal hedging as seen above or cottage style borders/beds due to its busy habit but its hardiness, surviving winters to -10°C.

Propagate yourself via semi-hardwood cuttings, carrying out pruning in mid-late spring. Prune out dead, diseased and damaged stems before thinning crowded stems and finally mulch the soil.