Q.I Planted 3 Russian Sage Plant 3 Years Ago- So Far Very Little Growth. What’s Wrong?
They get 6-7 hrs sun daily, and are in dry soil w/ adequate drainage.

Certified GKH Gardening Expert
Your hardiness zone (3b to 4a) is too cold for Russian sage. They may lose their vigor over winter and just limp along in the summer. Try adding a layer of gravel around the plants and in winter add a 2 inch layer of pine needles as mulch and see if that helps. Remove the pine needles in spring.
If you haven't fertilized since planting, add some compost around the plant or add a handful of general fertilizer. Also cut them almost to the ground in early spring.
https://www.gardeningknowhow.com/ornamental/flowers/russian-sage-flowers/russian-sage-care.htm