Salvia Leucantha: Pruning and propagating Mexican bush sage

GLORIOUS GROWTH: Mexican bush sage, or salvia leucantha, is a hardy hedge plant that display vibrant purple flowers during autumn and winter. Pictures: Hannah Moloney and Anton Vikstrom.
GLORIOUS GROWTH: Mexican bush sage, or salvia leucantha, is a hardy hedge plant that display vibrant purple flowers during autumn and winter. Pictures: Hannah Moloney and Anton Vikstrom.

The salvia family is a beautiful one.

My favourite is the Mexican bush sage (salvia leucantha) - I love it for its vibrant purple flowers, which come in autumn and winter, exactly when we need them.

Every so often we'll seen a brave bumble or honey bee feeding off them in this time of the year when most other garden flowers are sleeping - so its everyone's friend.

We've planted them at the base of a row of native hop bushes (dodonaea viscosa), which will eventually be hedged tightly and all the prunings will be fed to our goats.

How to prune

In order to keep this glorious colour and fresh foliage coming back again and again, you need to prune them hard once a year.

All you need to do is cut all the one year old growth to the ground once you see their flowers dying and fresh, new shoots coming out of the base.

If you look to the base of the plant, you'll see new shoots popping up next to the older shoots as seen above. Simply cut all the old shoots off at ground level. Because I wait for the shoots to come, I never have any bare ground.

The flowers start to fade towards the end of winter - this is the time to prune them. If you're in a region with serious frosts, it's best to wait until there's no risk of frost before cutting the old growth.

How to propagate from cuttings

You'll be left with a lot of vegetation. Instead of just throwing this in the compost or chook run, you can make many, many cuttings from it to grow more plants - because you can never have too many salvias.

To propagate salvia from cuttings, cut a piece of the hardwood from the old wood with four to five nodes showing.

Nodes are the part of a plant stem from which leaves or roots emerge, often forming a slight swelling. Make sure you have a node near the bottom of the stem.

Strip all the leaves from stems - I'll often leave one small leaf at the top to help photosynthesise. But if any of the leaves start to wilt and die, nip them off and don't worry, the cutting will still strike.

You can then plant up to five cuttings in each pot. Once they start setting roots in the warmth of spring you can move them up into their own pots to grow nice and big before eventually putting them into the garden.

For this batch I made the potting mix out of 40 per cent compost (but really you don't even need this) and 60 per cent coco peat (to hold onto moisture) as this is all I had available.

I could have done the whole lot just in coco peat and it would have been fine as well. Usually you'd also put some sand in there for good drainage - but these are hardy cuttings that don't need pampering.

And that's it. I now have 65 salvia leucantha cuttings, which will grow into vigorous bushes of glory. And no, that's not too many - I will happily home them all throughout our garden.

  • Hannah Moloney and Anton Vikstrom are the founders of Good Life Permaculture, a landscape design and education enterprise regenerating land and lifestyles.