Alan's Ornamental Plant of the Month; Ice Plants

AlanGardenMaster
Published on September 10th 2019
32
a butterfly on a Sedum flower

I'm spoilt for choice when it comes to picking my Plant of the Month for September as lots of flowering plants are at their best. But because of their fantastic bee and butterfly magnetism, I've gone for the Ice Plant.

Ice plants are easy to grow, have attractive foliage when not in bloom and look great with other garden plants at this time of the year. In this article, I'll take you through the most popular varieties but also tell you how and where to grow them. Also, if you're interested in gardening for wildlife (as I am), then this is a plant for you!
Bees on a pink flower on a plant
Bumblebee and Honey bees

Don't Call Me Names!

The common names for ice plants are quite simple, and Ice Plant is the most widely used. But you might hear this plant also described as 'Butterfly Stonecrops' or simply 'Stonecrops'. You'll find the 'Ice Plant' name applies mostly to the larger, herbaceous perennial types and 'Stonecrop' used more for the ground-hugging, rockery types.
A yellow flower on a stonecrop Sedum
A stonecrop Sedum

The Big Split

Simple so far, right? However, those plantgeeky botanists do like to meddle! These plants were until recently all called Sedum (their generic botanical name).
Now some are referred to as Hylotelephium. Doesn't quite roll off the tongue. However, it does mean 'woodland distant lover', so perhaps there is some romance attached to it.
But don't let this put you off growing these great garden plants. With any luck, before long that ugly name will be turned back into 'Sedum' again! There are already signs that this is happening.

Likes and Dislikes

I think that it's fair to say that all Ice Plants and Stonecrops love to be in the sun.
They don't mind poor soils but will tolerate richer ones too. Good fast drainage is also a must. So if your garden soil has less than perfect drainage, add some coarse grit to the soil before planting. Aim to add about half a bucketful per planting hole.
If that's not easy, then I'd suggest raising the soil into a mound and planting on top.
Ice plants are ideal for the container gardeners among us. Fortunately, although the flowers come late in the summer, the foliage is also good looking.
A collection of Sedum in a trough
A collection of Sedum in a trough

Wildlife Credentials

Place an Ice Plant in the sun and the wildlife will come! Tortoiseshell, Red Admiral, Comma, Peacock, Painted Lady and Fritillary butterflies all love this plant. You'll see all these - and more - when your Sedum are in bloom!
Small Copper butterfly on Sedum blooms
Small Copper butterfly on Sedum
These butterflies will be rubbing shoulders with wild and hive bees, bumblebees of all sizes, the occasional wasp and other insects to get to the nectar.
The open flowers are easy for insects to feed from and provide an important food source as the end of summer approaches.
Bees and Butterflies on pink Sedum flowers
Bees and Butterflies on pink _Sedum spectabile_ 'Brilliant' flowers

Pruning

Ice Plants require just one annual tidy up. You can do this just as soon as the plants have finished blooming; when all the nutrients in the stems and leaves have gone back to the roots.
You can leave dead flowers to stand over winter if you prefer. Birds will eat any seeds produced, and on frosty mornings they will be coated in beautiful hoar frost.
Stonecrops need no pruning at all. However, if they outgrow their space, they won't sulk if you need to cut them back a bit. They also tend to be evergreen, meaning that their foliage - often highly coloured - provides year-round interest.
A close up of a person pruning in a garden
Pruning some shoots in May to extend blooming time

Propagation

Rather like succulent plants, Sedum are easy to propagate. The low growing evergreen ones (Stonecrops) will easily root from cuttings at any month of the year. The herbaceous perennial ones (Ice Plants) are best propagated by dividing clumps up into smaller sections with roots attached. You can divide your plants in late autumn and early spring.
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Pests and Diseases

Very few pest trouble these plants. If you're growing them in pots, then keep an eye out for vine weevils. If they get attacked, you can treat your plants with a biological control agent - usually made up of nematodes that only target vine weevil larvae.
Some varieties suffer from powdery mildew, which tends to appear when the plants are stressed. So if you keep them happy, you shouldn't see this powdery grey coating on the leaves. If it does appear, treat with a fungicide immediately.
Mildew on plant leaves
Severe powdery mildew on a _Mahonia_

Drying

Some of the Ice Plant varieties will dry naturally. You can cut flower stems when the colour fades from the petals and hang them upside down in a cool and airy place, such as a garage or shed. The leaves will fall off, leaving just the stem and dried flowers.
Sedum Herbstfreude in winter
Sedum 'Herbstfreude' in winter

Recommended Varieties

As only a few of the low growing stonecrop varieties flower in September, I'll concentrate on the Ice Plants.
But I must mention that it was a stonecrop that won the best new plant at RHS Chelsea Flower Show this year! This one has very striking variegated leaves and is called Sedum takesimense ATLANTIS ('Nonsitnal'). I will be trying it in my garden for sure!
 Sedum takesimense Atlantis
Sedum takesimense Atlantis
If you have space for only one plant, then it has to be Sedum spectabile Brilliant. It's not the showiest, but for attracting insects, this one is in a class of its own.
Sedum 'Herbstfreude' is another widely available variety, and rightly so as this is a first-rate plant!
I quite like Sedum 'Bertram Anderson' and think it is slightly better than the similar 'Ruby Glow'. Both varieties scramble over the ground so are suitable for the very front of borders.
Sedum Rosy Glow with Artemisia schmidtiana
Sedum 'Rosy Glow' with Artemisia schmidtiana
If you like plants with purple leaves, then you'll love 'Matrona', 'Purple Emperor' and 'Red Cauli'. Purple Emperor has a habit of rotting during wet summers so would suit the drier, eastern half of Britain. 'Red Cauli' seems to be more robust but grows to a smaller size. 'Matrona' is widely grown but tends to get mildew. Planted with grass it can be a very effective ornamental plant.
A close up of a Sedum flower
Purple leaf Sedum 'Red Cauli'

Plant Combinations

The perennial Ice Plants look great with Cone Flowers - Echinacea, Russian Sage - Perovskia, Pony Tail Grass - Stipa tenuissima and Knotweeds - Persciaria.
September flowers in a garden
_Sedum_ 'Herbstfreude' with _Echinacea_, _Perovskia_ and _Persicaria_
The ornamental oregano called Oreganum 'Herrenhausen' looks fantastic with Sedum 'Matrona' and both are wonderful plants for bees.
Sedum Matrona with Oreganum Herrenhausen
Sedum 'Matrona' with Oreganum 'Herrenhausen'
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