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Salvias vary greatly in their hardiness and all make great garden plants.
Depending on your region, you may be able to get away with cutting them back in autumn and covering with a good layer of mulch. I wouldn’t risk doing this with Salvia discolor, the Andean silver-leafed sage – a particularly beautiful tender variety with a striking contrast between the almost black flowers against pale mint foliage.
And I’ve definitely lost some Chocolate cosmos trying to overwinter it in the garden – it simply didn’t survive the cold wet weather so my next one will definitely be coming indoors at the end of the growing season.
Finally, it’s a lovely time of year to bring out your tender house plants on to your patio or balcony where they can enjoy some fresh air and bring some exotic heat to your outdoor space.
Q
I have a large Hibiscus syriacus Red Heart, which has been grown as a standard. It is now leaning over badly and I’m finding it impossible to get it to grow straight.
I don’t want to get rid of it as it has great sentimental value to me.
I wonder if I cut it off close to the soil in the autumn, will it grow up from the root?
I have tried growing a cutting but with no success. Carol Doust, via email
A
I think it would be drastic and probably disastrous to cut a hibiscus back hard, particularly as it has been trained as a standard with a thick woody stem.