If you cut your plant back hard, it will impair both blooming and growth. At this time of year, axillary growth a few nodes below the flowers send out new shoots, and these are compact, blooming after sending out just a few pairs of leaves. This is especially true for the greggii types. The taller microphylla forms can be trimmed a bit more. It is very tedious to remove the short stems of spent flowering spikes.

I don't worry about this, especially if I want to collect seeds. In many areas, this is futile. Seed set and collection is difficult because bumblebees mess up the flowers and prevent pollination. I just ignore the short, fine twiggy stems until the weather cools down, and foliar growth resumes at the end of blooming.

Cutting back hard on a small plant is not advised, since new spring growth starts primarily at the robust stems below last year's blooming. There is also some sprouting of new stems at the base, and finally some along the middle parts of the stem, though this is the last to activate.

Established microphylla forms can be cut back hard with 6 - 8 inches of old trunks in late autumn, but beginners should do this in the spring, when the plant will reveal where it wants to sprout. This will tell you where to cut back for the following season. I take my advice from observing what my plants want under my particular circumstances.

thanks Richard...just what I needed to know. I assume that goes for the Nemorosas as well thanks bob

Nemarosa sages are alpine Eurasian specis with deep taproots and basal rosettes of leaves that stay close to the ground. The rapid development of stems is the initiation of the flowering sage, and when all blooms from the axial stems as well as the main stem are spent, it is time to cut them back, unless you want to collect seed.

The difference between the two types of sage is one of their adaptation to their environment. Greggii/microphylla plants are low elevation, lower latitude plants in an arid environment with well-timed rainy seasons (think the monsoon season in the southwestern USA) , whereas the alpine, higher latitude Eurasian species locate their perennial biomass closer to the ground for better survival during harsh winters.

You can learn a lot from Salvias from studying their appearance, then their behavior. If you have the curiosity, resources, and access, try a lot of experiments or make visits to your nearby botanic garden (if you are lucky to have one) and study both the plants and the environment and weather patterns..