Russian sage is a beautiful plant that has gorgeous purple flower spikes in July and August. Not only is Russian sage attractive, it’s extremely drought tolerant. It makes a fabulous low maintenance addition to Colorado landscapes. It’s also pretty commonly used.
How should you cut Russian sage back in the spring? Be sure to watch my video that shows you the two best methods to prune Russian sage in spring.
Keep in mind it’s a “subshrub,” meaning the top half of each stem dies back each year, but the bottom part of each stem lives through the winter. This can make the whole process a little confusing.
Option one for bold people
Cut all the stems to the ground. This is my favorite option for mature Russian sage plants located at elevations under 7,000 feet. It helps keep the plant fresh-looking and clean, since all the old growth is removed. If the stems are left intact for years, they become grey, old, overly woody and ultimately unsightly. Removing all that growth makes a plant more symmetrical and mounded in its shape. Be sure to cut the stems as close as you can to ground level. Don’t leave any stubs. The new stems will be light grey and supple.
Cutting Russian sage back to the ground usually doesn’t affect the flowering time much. It might be a week later than normal, but the effect on flowering is almost unnoticeable. The flowers will be normal size, with the plant producing the normal amount (or even more).
Don’t worry about injuring these plants with this method. These plants are adapted to periodic fire, so they regenerate perfectly well from the crown. If you’re worried about the results, simply try this method on one plant. Then you can judge the results for yourself. If it works, you can do more the following year.
Option two for more conservative folks
If you’re worried about injuring the plant, you can take a more moderate approach. Step back and mentally divide the height of the plant into thirds. With each stem, cut off two thirds of last year’s growth, leaving a third of the original height in place. For example, if the plant was four tall at the end of last summer, cut each stem to 18 inches tall or so. This method ensures you cut off all the old growth, but you leave the live portion of the stems.
Taking a more conservative approach guarantees that Russian sage will grow to its full height and flower right when you expect it. This is also a good approach for plants were recently transplanted and haven’t reached their full size.
Option three for high elevation areas
If you live above 7,000 feet in elevation, cutting all the stems to the ground may not work that well. The plant will spend a long time growing new stems. By mid-summer, the plant will be shorter than normal and bloom later, or may not bloom at all before the growing season is over.
Instead of taking such a drastic approach, wait until the new leaves start to come out in May. Then simply cut off the dead portion on each stem. Clip right above a newly emerging leaf. After you cut off all the dead material, step back and notice how symmetrical the plant is. Trim back irregular height stems in order to make a nice, mounded plant.
Don’t do nothing
If you leave Russian sage alone, it won’t look attractive. The new growth that emerges this year will grow into the old, dead material from last year. The flowers will be obscured by all the dead stalks, and the whole plant will have a brown-grey cast. Instead, choose one of the three options, take action and look forward to a beautiful plant in the middle of the summer.
Feel free to alternate between different methods each year. It’s perfectly fine to rejuvenate a Russian sage shrub that’s several years old by cutting it to the ground. You can then be more conservative the following year, then cut it to the ground again some time in the future.