Salvia are elegant plants with beautiful purple, red and white spikes that are hard to resist. But unfortunately that doesn’t make happy to share their space with anything you decide to plant alongside them.
A mixed border I tried making years ago that had Salvias in was a disaster. They ended up looking thin and pathetic and the other plants I planted with them didn’t do much better.
So Salvia won’t grow well with simply anything. Like lots of other plants they can be picky about what they share their space with.
So I’m going to go through the plants they won’t get along with and explain why. That way you won’t make the same mistakes I made.
Understanding Salvia
The first thing you need to know about salvia is that there are actually over 900 species of them. The most common one’s though are salvia splendens (scarlet sage) and Salvia nemorosa (woodland sage). Chances are it’s one of these you’re growing.
What makes salvias tricky companion plants is that they have specific needs and are extremely competitive in nature. They’re drought tolerant once established but they also take a lot nutrients from the soil during their growing season. They love a lot of sun but can get leggy and weak if they don’t get proper air flowing around them.
Most importantly though is that they release substances through their roots that can either help out or interfere with plants near them.
It’s easy to think of salvias as low maintenance border plants you can plant anywhere you like. But you’d be Wrong.
They’re picky. And when they’re unhappy they’ll let you know by producing fewer flowers, picking up diseases or just looking generally miserable.
They can also be surprisingly territorial. In their native habitats they often grow in areas where they’ve had to fight with other plants. So they’re programmed to be aggressive when it comes to resources.
Why Getting Salvia Companions Wrong Matters
Get the wrong companion plants with salvias and you will end up with several annoying problems:
- Stunted flowers – salvias, which are usually happy to produce tons of flowers, will barely produce a handful of spikes
- Much more likely to get diseases, especially powdery mildew and root rot
- Weak, leggy growth instead of the bushy plants you’re expecting
- Neighbor plants not doing well or producing poor harvests
- Wasted money and garden space on plants that never grow as big as they have the potential to
Plants NOT to Grow With Salvia
1. Impatiens
This pairing looks amazing when you see at your garden center but it’s a disaster waiting to happen if you plant it in your actual garden. I tried it in a semi shaded area thinking the salvias would appreciate some afternoon shade and the impatiens would love the morning sun. Both plants ended up looking terrible.
Why it fails:
- Completely opposite water needs – impatiens need consistent moisture while salvias prefer to dry out between being watered
- Impatiens need rich, organic soil and salvias do better in leaner conditions
- As impatiens need constant moisture this leads to the exact conditions for salvia to develop root rot
- Salvias has a deep system of taproots and they compete hard with impatiens shallow roots
2. Hostas
Hostas and salvias are simply incompatible. I tried planting them together and the hostas never developed the full and lush leaves they’re known for. Ans the salvias stretched toward any available light, very clearly desperate for it.
The problems:
- Hostas need shade and salvias can’t do without full sun for proper flowering
- The levels of moisture they both need are completely different
- The compounds salivas have will stop hostas growing
- Totally different needs when it comes to soil pH levels. Hostas like slightly acidic soil while salvias prefer neutral to alkaline
3. Azaleas and Rhododendrons
On the face of it this seemed like a perfect combination. Spring blooms of azaleas followed by summer salvias. When I tried it though all I got was weak azaleas and salvias that never took off.
Why they clash:
- The soil needs clash. Azaleas love acid and salvias prefer neutral to slightly alkaline soil
- Salvias aggressive roots will damage the shallow roots of azaleas
- Watering schedules don’t match up at all. Azaleas need consistent moisture
- Both need a lot of feeding but the fertilizers they like are completely different
4. Begonias
The colors of begonias and salvias together looks fantastic in photos. But in real gardens it’s a verybdifferent story. My begonias developed weak stems and produced fewer flowers when I planted them near salvias.
What goes wrong:
- Begonias need more water and humidity than salvias can tolerate
- The allelopathic effects of salvias stunts begonias growth
- Both are susceptible to fungal disease and they can then spread at speed between the two
- They really compete for nutrients during the growing season
5. Ferns
When I tried to make a woodland edge with salvias and native ferns it didn’t work at all. As the season went by the ferns slowly declined and the salvias hated the moisture levels and shady conditions so never got close to thriving.
The issue:
- Ferns need consistent moisture and higher humidity
- Most ferns prefer acidic soil
- They need totally different amounts of light
- Salvias’ root exudates are toxic to lots of species of ferns
6. Coleus
This combination is popular in container plantings but I’ve never seen it work well in the long term. The salvias get too much water which leads to problems or the coleus get overwhelmed by them.
Why it’s problematic:
- Coleus needs consistent moisture and can’t handle the fact that salvias prefer the dry
- Both compete for the same nutrients
- If planted in containers then the roots compete far too aggressively
- When you water one plant is stresses the other
7. Lettuce and Leafy Greens
Sometimes you think two plants will make good companions because they help each other out. That was what I thought when I planted salvias near a patch of lettuce as they keep deer away. Instead the lettuce grew poorly and bolted much earlier than usual.
What happens:
- Lettuce have shallow roots that can’t compete with the salvias deep ones
- The aromatic compounds in salvia can make leafy greens taste bitter
- Different needs when it comes to fetilizing. Lettuce needs nitrogen rich soil and salvias like balanced nutrition
- Can be tricky to manage as they very different harvesting times
8. Astilbe
Another combination that seemed like they’d go well together. But the astilbe struggled in the sunny and dry condition that the salvias needed.
The problems:
- Astilbe needd consistently moist and rich soil
- Astilbe likes partial shade and that conflicts with the salvias need for lots of sun
- How much competition the roots face with each other damages astilbes crown
- The pH preferences are different enough to cause deficiencies in nutrients
9. Caladiums
I didn’t think these tropical looking plants would have any problems with salvias. But after trying to create a border with them it was a total failure.
Why they clash:
- Caladiums need high humidity and lots of moisture
- They prefer partial shade while salvias need full sun
- Saliva needs well draining and the tuners of caladium rot in it
- Completely different growing seasons and times when they’re dormant
10. Japanese Painted Ferns
I was drawn to the silver foliage contrast with purple salvias. But after a few attempts I just couldn’t get this pairing to work.
The issue:
- They need acidic and organic rich soil
- Moisture requirements are completely opposite
- Caladiums have delicate fronds which get damaged by how aggressive saliva is
- Very different light needs
11. Bleeding Hearts
The fact that bleeding hearts are spring bloomers and they could be followed by salvias in the summer felt like great succession planting. But in reality the salvias’ summer growth interfered with the bleeding hearts’ period of dormancy.
What goes wrong:
- Bleeding hearts need to go dormant in the summer heat but salvias keep the soil active
- The roots compete during the time when bleeding hearts’ need to grow in the spring
- Their moisture needs are another part of that conflict, especially in the growing season
- The allelopathic effects of salvia can stop bleeding hearts from returning the next year
12. Brunnera
This was another one that seemed like it would create a lovely contrast with salvias. But in any of my attempts neither of them thrived together.
Why it doesn’t work:
- Brunnera likes partial shade and consistent moisture
- The silver leafed varieties are very sensitive to the compounds in salvias roots
- When both plants are at their peak in terms of growing it means they’re competing massively which each other
- pH requirements are different enough to cause some problems
Great Plants to Grow With Salvia
After a lot of things not working out these are a few combinations that work well:
- Ornamental Grasses – Fountain grass and salvias are great because of the contrast they have with each other and they share the same sort of needs when it comes to water
- Sedum – Both are able to go without much water and complement each another nicely
- Catmint (Nepeta) – Similar growing conditions and the blue/purple color combinations are really gorgeous
- Russian Sage – Another Mediterranean plant that shares salvias’ liking a lot of sun and good drainage
- Coneflowers (Echinacea) – Both attract pollinators and have similar needs
- Black Eyed Susans – The yellow and purple color combination is classic and they’re both tough plants that love the sun
Tips for Successful Companion Planting
- Match watering needs first – This is more important than color combinations. If the plants need different amounts of water then keep them apart.
- Consider mature sizes – Salvias can get bigger than you’d think and very bushy. Give them room or they’ll take over anything that’s smaller than them.
- Think about timing – Some plants can share space as long as their growing seasons don’t overlap.
- Test soil compatibility – A simple pH test can save you from pairing plants with soil needs that are too different.
- Use salvias as background plants – Their height work better behind shorter plants than when mixed throughout a planting.
- Group by maintenance – Plants that need similar fertilizing, pruning, care etc. work better together.
Final Thoughts
You don’t want to just avoid the plants that don’t work with salvias. What you want to do is understand what makes them tick.
These are Mediterranean plants that evolved in challenging conditions. So they’re naturally competitive and you can’t ignore what they need.
But there’s something else and it’s that gardening isn’t only following rigid rules. You should be looking at what actually happens in your garden and then open to moving things around when they aren’t working.
Some of the combinations I’ve listed here as ones that won’t work might actually have success in your garden if you have different soil, climate etc.
Just start with plants that have similar basic needs. Things like the amount of sun and water they need, what soil they likE etc. and then tweak it from there.
Salvias will give you months of wonderful flowers when they’re happy with their neighbors and it’s worth it when they do.