Growbag Blog

Overwintering tender perennials – is it worth the bother?


So you succumbed to temptation and bought a lovely salvia just starting to flower in late July and now it is still looking great but frosts are threatening and you are wondering what you should do.

Salvias are a bit of a task to keep going year on year, they mainly come from places like Mexico and Africa where winters are not as cold and wet as we get here, so a bit of forethought is needed.

Some of the hardier cultivars such as ‘Amistad’ (our feature picture above) and ‘Phyllis Fancy’ you may be able to leave in the ground with the safeguard of a good mulch – both cracking plants, you can have a look at both in my video this week  (try to overlook the music, Caroline is still at the ‘keen learner’ stage) . The smaller flowered jamensis  and greggii types need a very sheltered spot, perfect drainage and a dollop of good luck to see them safely through and there are the truly tender species such as leucantha (Louise’s Plant of the Month) and discolor with which you have absolutely no hope at all.

Salvia ‘Stormy Pink’
Salvia jamensis ‘Stormy Pink’ has come through several winters in a sheltered bed with me

So you need to set aside time to take cuttings, around August, which will root pretty easily in small pots that will take up minimal space on windowsill or frost free greenhouse, and can be planted out again next spring.

mauve salvia
Salvia ‘Phyllis Fancy’ – you may be lucky and get it through outside but unlike my lazy sisters I usually take a few cuttings as well to be sure

Some people, aka my sisters, think this is too much trouble and won’t bother. My view on it is that time is a finite commodity with many fixed and immutable demands upon it (working, shopping, watching Bake-off….) so in gardening, as in life, there are choices to be made on how you spend your time; what is important to you; what gives most back to your wellbeing and happiness. This may result in you having a neat and tidy garden, or a well stocked vegetable plot. For me it is a garden full of unusual plants from all over the world that enchant me.


You are so right, Laura, that I find a great deal more to do in the autumn than faffing around with precious little princesses.  No question – Laura’s exquisite rare salvias always blow me away when I see them in her garden in late summer, but then a line from Andrew Marvell’s To His Coy Mistress springs to mind ‘Had we but World enough, and time’……but I DON’T have World enough, or time, or a greenhouse, or inclination, to be fannying around with individual high-maintenance WAGS of the plant-world – moving them in, or tinkering about with cuttings, over-wintering them, growing them on, moving them out again – no, no, no, not for me.  

If it’s not an annual and can’t get through the winter (and I know I am very fortunate in being able to grow a lot more outside than either of my sisters) without all the mollycoddle-stuff, you won’t find it in my garden.

Autumn is a time for moving and dividing, cutting down, taking a critical view.

A ‘Rozanne’ type geranium called ‘Bankside’ has delighted me this year and is still in charming flower.  I will divide it now while the soil is still warm and wet, and the divisons will grow away quite the thing next spring, no mollycoddling for them.  And you can do that with hundreds of plants – phlox, asters, persicarias, bergenias, achilleas, campanulas, lots and lots (but leave things that like dryer conditions and grasses and divide them in the spring).  

Purple geranium
Geranium ‘Bankside’ – Give it a short back-and-sides after flowering

More than enough to fill your time in autumn without resorting to the horticultural navel-gazing of tender perennials.  And if you’re still short of something to do, look around at the glowing jewels on Malus ‘Golden Hornet’, the flames of a maple, the astonishing purple berries of a callicarpa – stop and wonder.


Yes how irritating of Laura to advise us in, er, October that we should have been taking salvia cuttings in August. It’s reminiscent of the 1970s when she’d inform me that if I’d wanted to go on the school trip I should have submitted the form three weeks earlier.

Never mind the faff of taking cuttings, even here in the Highlands of Scotland, I have been amazed at how effective it is just to pull your pots in close to the house. Huddled against a south-facing wall I’ve overwintered things like Chatham Island forget-me-knot and melianthus, although, to be fair, it is very dependent on the type of winter it was.

Chatham Island Forget me Not
Chatham Island Forget me Not – survived a Highland Winter but needed a cosy wall location

But I’m not sure Elaine’s division suggestion is much of a solution either. Many of us don’t have space for MORE of a plant – frankly I have more of a challenge to contain what I’ve already got. I just want to hang onto what I’ve got in a location where horticultural fleece is as effective as a bride’s veil on a roller coaster.

I discovered from an RHS Wisley article that covering your plants in bubble wrap or plastic is a dumb-ass idea as they cant breathe and can rot, but fleece or hessian stuffed with straw is good if you have something like a banana tree (getting more popular but scarce I have to say, in the Scottish Highlands) that needs protecting.

For me mulch and luck have to be the answer.  Never mind the metaphysical poets, no one values their time more than me; at any one moment I know exactly how long it is until wine’o’clock, but even I can squeeze in a quick mulch-buying trip (or buy it online from Waitrose – it’s impregnated with anti-slug stuff too).

I find it slightly challenging to identify exactly where my ‘tenders’ are in the herbaceous borders, particularly if they flowered a while back, and I worry that if I heave hundredweights of mulch everywhere my delicate little irises will struggle to get through in March, but by that time the sun has tipped over the yard arm; my fears and responsibilities start to ebb away, the wine glasses beckon and I’m well up for a bit of stopping and wondering.

Grow bags tip– If you didn’t take cuttings in August, try to get your fussier salvias and other tender plants in a frost-free place overwinter. If you can’t lift them, apply plenty of mulch. Be sure to mark where they are so you can monitor for signs of life in the spring.

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By the3growbags

We're three sisters who love gardening, plants and even the science of horticulture but we're not all experts. We'd love everyone even remotely interested in their gardens to be part of our blogsite.

2 replies on “Overwintering tender perennials – is it worth the bother?”

I came across your site as I was looking up how to overwinter salvias. I live in zone5. For years, I have been bringing in my large pots that usually contain multi-plant, color plantings to then become disappointed that they would not all survive partly due to neglect and partly because I guess they’re not meant to. I LOVE SALVIAS and try to get as many different varieties that are available and affordable. Mostly I love how they bring more butterflies and hummingbirds than any feeder can. I’m excited to read more of your blog. My immediate question is where do you find your salvias? I’ve never seen the colors of Amistad and Stormy Pink. They’re lovely! Thank you and cheers to sisterhood!

Hello Carol, how nice to get your comment and sorry not to reply to you sooner.
I’m imaging you live in the States judging from your description of humming birds visiting your salvias – how exciting that must be!
I’m afraid I really don’t know how you would obtain the cultivars we grow in this country, such as Amistad and Stormy Pink, if they are not advertised in American nurseries. They are however, one of the easiest plants to grow from cuttings so if you see them in someone else’s patch you could always ask if you could snip a few little sprigs!
Best wishes Laura

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