Plants that take a bit of frost

We had a hard frost yesterday and it took the van a few minutes to defrost. I took the opportunity to take a some early morning photos in the garden.

I find photographing plants a helpful way to remember what plants do at different times of the year. And although being able to take a bit of frost without turning to mush doesn’t necessarily mean a plant is fully hardy; it’s useful to know which plants you can rely on for a bit of late autumn interest.

Like this Sporobolus heterolepis.

Slow to establish but very popular in the matrix planting associated with designers such as Piet Oudolf. This Sporobolus heterolepis is young and I can't wait to see it grow next year.

Sporobolus heterolepis, commonly called Prairie Dropseed is native to the tall grass and mixed grass prairies of central North America. In the Great Plains it receives bitter cold winters and harsh, chilling winds. So not surprising that it can take frost in Wickhambreaux.

S. heterolepis is a deciduous grass with lovely copper coloured autumn foliage (green in summer). This plant is still young so didn’t flower this year, but older plants hold onto their delicate flower stems into winter.  

A tough Australian

When I think of Australia, I think of baking hot sun and cricket players with thick layers of sunblock on their noses. And while Grevillea robusta needs a spot in full sun with a free draining soil, it’s surprisingly hardy.

Grevillea rosmarinifolia looks fantastic all year round. I love its rosemary-like leaves and clusters of small red flowers. It's in the Proteaceae (Protea family), which is named after the prophetic sea god Proteus. Proteus was said to take many different forms, much like plants in the Proteaceae.

The RHS say that G. rosmarinifolia is hardy down to -10°C, but when I worked at Wisley I saw this plant put up with closer to -16°C!

While some plants take frost with a bit of complaint (darkening leaves and indications of stress), G. romarinifolia doesn’t even appear to notice the cold.  

Still flowering

Meanwhile, some plants that are known to flower in summer are still going strong. Check out this Helenium ‘Sahin’s Early Flowerer’.

Helenium 'Sahin's Early Flowerer' is a very floriferous, reliable, and upright perennial in the Daisy family (Asteraceae). But is this really it? Perhaps it was wrongly labelled when I bought it. We will see!

Actually, I’m beginning to wonder if this plant was mis-labelled. I bought it this July. It’s supposed to be a lot taller than this and more orange.

The fact that I bought it so late in the season would explain the height. It may have been cut back multiple times earlier in the year and treated with growth regulators in the nursery. However, these flowers are very yellow, not orange.

Don’t get me wrong, I really like it! But I need to make sure it’s correctly identified so I can show clients how it behaves in a garden setting.

I will see how it grows in 2025. If it doesn’t start to look like H. ‘Sahin’s Early Flowerer’, I will have to try and identify it.

Moving on, our Salvia are still going for it. This pink one is a cultivar called S. ‘Angel Wings’. Very nice! 

This might be my current favourite Salvia. I like the two-tone, pale pink flowers. Not too in your face.

And this popular purple and white flowered cultivar is called S. ‘Amethyst Lips’. Not that you can see the flowers due to the amount of frost on it.

Beneath the frost are white flowers with a purple lip. Because of the size of the lip, the flowers are mostly purple, but they do have "white tops".

Growing just behind the Salvia, Mahnoia japonica is doing its thing. Very much expected for this time of year. M. japonica is a reliable one.

You can always rely on Mahonia to flower well in the coldest months. I love the strong winter fragrance of this species.

Verbena-like ground cover

Glandualria corymbosa is a new plant to me this year. It’s in the Verbenaceae (the Verbena family), but unlike the well known and loved tall Verbena bonariensis, this one is a bit of a creeper.

I really hope that Glandularia corymbosa spreads throughout the border to cover and protect the soil. At the same time I hope it's not invasive. I know that is walking a tight line! In the foreground is Epilobium canum 'Ed Carman'.

So far, I’ve only planted one plant of G. corymbosa; but I imagine it could be a good gap-filler. It’s already showing its creeping nature by throwing out a couple of long horizontal stems, and I’ve found it to root from cuttings very easily and quickly.

It’s not a stretch to imagine that it could layer itself throughout a border; and yet it doesn’t strike me as an invasive plant. We will see.

I’m looking forward to seeing it flower for the first time next summer.

A few good seed heads

I love a good seed head, and our newly planted garden has plenty. This one is Agastache ‘Blackadder’. A Korean friend from Wisley once told me that they eat this mint-relative as a herb in his homeland.

The tall stems of Agastache 'Blackadder' are putting up with the cold weather so far. They also stood up to the storm we has last weekend.

I enjoy looking at gardens as landscapes. Get close to the ground or canopy level and look horizontally. You could be a flying insect or bird making your way through this fabric rich in shapes, colours, and textures.

A view through the increasingly diverse landscape of our home garden.

Here you can see the pink spikes of Salvia nemorosa ‘Caradonna Pink Inspiration’, the leaning, top heavy seed heads of Dianthus carthusianorum, short and fluffy seedheads of Aster amellus ‘Rudolph Goethe’, and the rounded seed heads attached the tall stems of Monarda ‘Scorpion’. In the background, you can just about make out the spikey inflorescence of Pennisetum alopecuroides, and the spreading mound of pink flowers on Salvia ‘Angel Wings’.

Californian Fuchsia

I’ll finish on a plant that I’m really excited to see flowering next year. Epilobium canum ‘Dublin’ is known as Californian Fuchsia; and despite coming from such a hot area, it takes the cold without a second thought.

This Californian native doesn't seem to mind the cold weather.

Unlike the Cape Fuchsias (Phygelius aequalis and P. capensis) which are in the Figwort family (Scrophulariaceae); Epilobium, joins Fuchsia in the Onagraceae. 

It has loads and loads of really amazing red, trumpet like flowers in summer and autumn. In its native range, these are pollinated by hummingbirds, and likely a whole range of insects.

Ours hasn’t flowered properly yet (a few flowers did come), because it was propagated this summer and because I’ve been taking even more cuttings this autumn. But fingers crossed that next year there will be an amazing display that will attract lots of pollinators!

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