In this post I share what I know about pruning the two most popular types of perennial salvias which you probably have in your own garden.
Salvias are popular all the world over and are so versatile because they can comfortably fit into many styles of gardens from old fashioned cottage right up to modern simplistic. They grow well here in California where our Mediterranean climate suits them to a tee and they’re loved because of their long bloom time. It’s an added bonus that their non thirsty ways are so appropriate for the water starved western US.
I first learned all about perennial salvias in the San Francisco Bay Area where I was a professional gardener for over 15 years. The nursery where I worked in Berkeley sold many different species and varieties of them. This post is all about sharing what I know about pruning (this is the big cutback, not the dead heading you do throughout the season) the two most popular types of perennial salvias which you probably have in your own garden. Plus, I also mention a 3rd type which you may not be familiar with. I did a post on pruning perennial salvias a few years ago but the video that went with it was under 2 minutes long. Time for an update with much more detail.
I’ll be talking about pruning salvias here in coastal California. You can tweak the process for your climate zone if they’re perennials where you live. There’s a long standing debate of sorts about giving salvias their big pruning in fall vs spring. It’s simply a matter of preference. I go back and forth on this topic but these days am more a proponent of fall/winter pruning. I sometimes find it necessary to do a light “clean up” pruning in early spring too.
We have lots of year round interest in our gardens so that’s why I prefer to do it in mid to late fall. This way the plant looks better over the winter months and growth is nice and fresh earlier on in spring. If you’re in a colder climate, just make sure to prune in the a fall well before the threat of frost and after the last chance of it has passed in spring.
#1 The Deciduous Herbaceous Salvias.
This category includes: Salvia elegans, S. guaranitica, S. leucantha, S. waverley, S. ulignosa & S. patens. With these salvias the old growth eventually dies out and the fresh new growth emerges from the base of the base. They have softer stems which either die off and/or freeze. These types of salvias are better to prune in spring (in colder climates) because the old growth will protect the fleshy new growth over the winter. In the video you see me working on a Salvia leucantha (Mexican Bush Sage), Salvia elegans (Pineapple Sage) and Salvia Waverley which I just talk about. These salvias are very simple to prune. When they’re through flowering, simply cut those stems all the way down to the ground. It needs to be done once or twice a year. They will still flower if you don’t but you’ll get more blooms and the plant will look 100% better if you do. Here in Santa Barbara the leucanthas and the waverleys get huge. Many of them are not cut back leaving a tangle of dead twisted stems and they look like a ratty mess. I want to prune them all back but don’t want to get arrested for trespassing! So, it’s best to give them the shearing back they need because this lets in the light and air they need to regrow. That allows the soft new growth to appear at the base. Another thing to know is that these salvias tend to spread as they grow so you might have to do a bit of dividing.
#2 The Herbaceous Salvias With Woody Stems.
This category includes: Salvia greggii (there are so many of these!), S. chamaedryoides, S. coccinea and S. microphylla (there are quite a few microphyllas too). These are the shrubby salvias. You prune these salvias back after flowering but not all the way. Take them back to at least where the first set of foliage starts on the flower stem – this could be a pinch or you can take them down further if they need it. I learned the hard way on an established plant to not cut it down to 3″. It never fully came back and out it came. With these types of salvias I thin out what I want in the middle and then shape the plant so it’s pleasing to the eye.
They usually go through 3 bloom cycles throughout the year here. We have a long growing season. I give them their “more intense” pruning in late fall or early winter and lighter ones in late spring and mid summer. Be sure to take out any growth which has died over the winter. If you don’t give these salvias some type of pruning they will get extremely woody and won’t repeat bloom like you want them to. Plus, they get straggly and sparse – not a pretty sight in the garden. In my years of working with salvias I found that some needed to be replaced before or around the 5 year mark. This is especially true with this type. Perennials don’t live forever after all. No worries though because they grow fast, especially if you purchase a 1 gallon plant.
#3 The Rosette Forming Herbaceous Salvias
This category includes: Salvia nemorosa, S. x superba & S. penstemonoides. These salvias form low rosettes (which are evergreen here) and the stems with more foliage and the flowers emerge out of them. The 1 that you see me pruning in the video is Salvia nemorosa (Meadow or Woodland Sage) and I’ve found that this has a very long bloom time. I prune the stems all the way down to the rosette and also clean up any dead foliage growing close to the ground.
The leaves tend to grow densely on this 1 so the undergrowth gets smothered. Bottom line: It’s best to know which kind of salvia you have before springing into action with the pruners. All 3 types of perennial salvias really benefit from a good haircut. You’ll get much better flowering and shape if you do so. Whether you prune in fall or spring is up to you. Just keep those salvia blooms coming please – the hummingbirds and butterflies agree!