Posted: Yesterday at 18:15
Owen........like many of the shrubby herbs, their lifespan can often only be 2 or 3 years for a really strong growing plant.
If you cut them regularly, they should stay bushy.
It could be that the larger Silver is overcrowding the creeper......with plants of differing growth habits, it is often better to keep them in individual pots.
You can reinvigorate the plants by trimming out the dead bits ( not into really old wood if you can avoid it ) and then mound some very gritty compost into the centre of the plant.......if you do that at this time of year, the chances of getting new growth is good.
Taking cuttings is a good idea too so that you will always have the plants to grow on