Be careful when you prune Californian lilacs. They need shaping up but might refuse to produce new branches from old wood. Different rules for evergreen and deciduous ceanothus shrubs apply.
Prune your large succulent sedum plants so that they don't fall apart.
Sedums are a huge family of plants, many of which require no pruning at all. However, there are some commonly used garden varieties, and you may well have sedums in the ‘Brilliant’ and ‘Herbstfreude’ groups (Sedum telephium) located in your borders and flowerbeds. These produce succulent stems with huge clusters of tiny star shaped flowers on top. They can often become top heavy, and can benefit from pruning twice a year.
Prune in November or January
The main time to prune sedums is at the end of the year once they’ve finished flowering. Stems will begin to turn brown and they can all be cut right back to soil level so that emerging growth in the spring has room to grow. Plan to prune sedums in November, or wait until January if you want to leave stalks for winter interest. Use your secateurs to remove all flower stalks at ground level as new growth appears.
Be brutal in spring
Mature sedums produce a lot of shoots, and the large flowerheads can cause stems to flop outwards so that the middle of your plant looks unsightly and bare. You can prevent this by pruning back the new growth. Whilst this may seem a little brutal, reducing this spring growth will keep sedum plants bushy and compact, in addition to preventing top heavy stems from snapping or bending. So in late spring, remove 5cm of new growth by using secateurs to cut through each fleshy stem.