Great Companion Plants For a Cottage Garden: Geraniums

This post about hardy geraniums, popularly called cranesbills, (not the pelargoniums) is the second in my series on companion plants.

Blue hydrangea with geranium companion plant
Blue hydrangea with a geranium companion

What are companion plants?

Companion plants complement the showy ornamentals society loves – roses, peonies, delphiniums and hollyhocks – filling in the gaps in the flower border and helping it flow. They’re pretty enough on their own terms and happy to mingle in, above or below other plants. Good neighbours, they will not compete too aggressively for food, water or space.

Geranium 'Dreamland' with Achillea 'Saucy Seduction'
Geranium ‘Dreamland’ with Achillea ‘Saucy Seduction’

Their presence encourages a healthier ecosystem by attracting beneficial insects which is why companion plants are often recommended for kitchen gardens. To find out more about what makes a plant a good companion, check out the first post in the series, on astrantias.

Pink roses with purple geraniums at a sunny Bodnant Gardens
Roses with geraniums at Bodnant Gardens

Geraniums (Cranesbills)

If you show me a decent sized English garden that doesn’t have a geranium, I’ll show you a garden that is missing a trick. Suppliers variously describe them as forgiving, easy, undemanding, generous and enduring. I don’t have a horse in the race, but I’d agree with them.

Geranium Sue Crug and Stachys byzantina
Geranium ‘Sue Crûg’ and Stachys byzantina

The main reasons to grow hardy geraniums as companion plants include their:

  • Impact in the mass
  • Long flowering periods
  • Beauty, delicacy and colour of the small, individual flowers
  • Attractive foliage (some have great autumn colour)
  • Ability to fill gaps and cover ground
  • Longevity
  • Happiness in sun and partial shade in anything but waterlogged soil
  • Drought tolerance once established
  • Ease of growing, requiring little attention or experience
  • Spending or mound forming nature, while unlikely to swamp
  • Ease of propagation
  • Attractiveness to bees, butterflies and other pollinators
Geraniums with tall grass by a pond at Jupiter Artlands
Geraniums with tall grass at Jupiter Artlands

Some growers contend that geraniums don’t particularly appeal to slugs, snails and rabbits, although if they are a slug’s only choice of food, all bets are off. I suppose if slugs were our only choice of food, the big ones would look delicious.

Rosa 'Harlow Carr' underplanted with hardy geranium
Rosa ‘Harlow Carr’ underplanted with geraniums in Mum’s garden

Writing about astrantias as companion plants was straightforward as they are broadly similar in flower, leaf, height and habit. Geraniums are another kettle of fish – their characters and habits are varied.

As I was writing the bullet points above, exceptions were springing to mind. I ended up imagining a series of job interviews for geraniums for a vacant spot in the garden at the stage when candidates are asked to share their weaknesses.

Geranium x magnificum (one of my favourites) would explain it only flowers once each year, but is guaranteed to get the season off to a magnificent start.

The oxonianums ought to admit that, as they are such good mixers, they cross easily and their myriad seedlings may be bland and/or straggly.

Geranium oxonianum 'Wageningen' has salmon pink flowers
Geranium oxonianum ‘Wageningen’

In their defence we can hand-pluck any nondescript seedlings out of the ground after they first flower and their straggliness is nothing a pair of shears won’t sort out in 20 seconds.

Bright pink Geranium psilostemon with yellow loosestrife
Geranium psilostemon with loosestrife

Geranium psilostomen should confess that if it is left for a decade or so to settle in then you ask it to redeploy elsewhere, you’ll struggle to shift it. On the plus side, it’s more than a match for other powerful personalities in the border such as yellow loosestrife (Lysimachia punctuata).

White geranium with ferns
G. macrorrhizum, G. dalmaticum and G. x cantabrigiensis are similar plants with different dimensions

Geranium macrorrhizum should say it will gradually smother a low wall if invited to tumble over it and suggest interviewing a Geranium dalmaticum if you’re looking for something daintier (but who’s going to do that in an interview?) Take a close look at this screen shot from the Geranium macrorrhizum entry in the RHS plant database:

Screen shot of the RHS website

Can you imagine any plant being less fussy about where we choose to put it?

Geranium ‘Buxton’s Blue’ might observe that the gardening elite thinks it is too prevalent to be fashionable, but that attests to the power and allure of its blue (and white) eyes. On the other hand, Geranium ‘Mrs Kendall Clarke’ could point to her enduring popularity at flower shows and claim she has no weaknesses at all.

Geranium pratense 'Mrs Kendall Clark' in the RHS Garden For Wildlife: Wild Woven
Geranium pratense ‘Mrs Kendall Clark’ in the RHS Garden For Wildlife at the Chatsworth Flower Show

Monocarpic Geranium maderense should say it is tender so needs winter protection and will take some time to get around to flowering, when it will astonish everyone with its glory and fade away so you’d better have a succession plan in place.

All geraniums could with justification claim they are too nice, too modest, too easy to overlook for promotion to one of the best garden spots, but that given a chance, they’d shine.

This isn’t all fantasy. The sheer number and variety of hardy geraniums for sale in the UK – species and named varieties – can make choosing seem tricky. We’re talking here about hundreds of species and thousands of named varieties ranging from 15 cm (6 in) or so high to 1.25 m (4 ft) plus.

Geranium 'Rozanne' has purple-blue flowers with white centres
Geranium ‘Rozanne’ was voted Plant of the Centenary

I had intended to link to the RHS’s Award of Garden Merit list, usually a good place for UK gardeners to start, but a glance through the 47 geraniums listed prompted me to wonder how recently the list has been updated. A scientific assessment of all the varieties available would be a big ask, and would not repay the resources needed to do it.

Purple geranium with bright pink Phuopsis stylosa
Geranium with Phuopsis stylosa

When all’s said and done, choosing a hardy geranium that will grow for a UK gardener isn’t one of gardening’s most difficult challenges. Pretty much any you see for sale will do just fine in our mild, moist climate. Pick from white, purple, blue, lavender or pink. By all means research to find out which varieties will be happy in your conditions.

Geranium macrorrhizum at Ian Hamilton Finlay's Little Sparta
Geranium macrorrhizum at Little Sparta

If you really want my advice, interview G. endressii, G. nodosum, G. phaeum and G. sylvaticum and their cultivars for shade; G.clarkei, G. himalayense, G. x magnificum, G. pratense, G. psilostomen and G. wallichianum for a border; G. macrorrhizum and G. cantabrigiense for wall tumbling and ground cover in sun or shade; G. cinereum, G. dalmaticum, G. renardii, G. x riversleaianum and G. sanguineum for a gravel garden.

A lot of information can be found on the label or online catalogue, but it’s always good to see a well-established plant to get a feel for its habit.

Arley Hall's wide double borders have a topiary structure
Clumps of blue geraniums brighten the front of Arley Hall’s double borders early in the season

Remember that the first rule of selecting almost any type of plant is to check the height and spread on the label.

Bold pink geraniums in the mixed border at RHS Harlow Carr
Bold pink geraniums in the mixed border at RHS Harlow Carr

Once you’ve sourced the ones you want, by and large the only gardening required for hardy geraniums is to plant them. Trim back the spent flowers if you prefer to keep things tidy, and wear a smile as you do it, knowing most geraniums will repeat flower better in response. Split the vigorous ones when they show signs of venturing somewhere you’d rather they didn’t.

“Simples”,  as the meerkats would say.

29 Replies to “Great Companion Plants For a Cottage Garden: Geraniums”

  1. Great post (though I think you’ll find it is Rozanne not Roxanne, though I do like the latter name as it was one chosen for my fourth child had it been a girl). And you introduced me to Mrs Kendall-Clark who now resides on my list for my raised bed. Hardy geraniums are THE best companion plants.

    1. Thanks very much for pointing that out. My spellcheck likes Roxanne too – it’s a menace with plant names. I could grumble a good bit more on the subject but I’ll refrain. 🙂

      I’m glad you think geraniums make the best companions. They are not as widely available in the US as they are here and I felt sorry about that as I was writing. Of course, they have many plants that we can’t just stick in the garden and forget about. Amaryllis always astounds me in my sweetheart’s part of the world.

  2. Excellent post. I especially liked the combination of geraniums and roses. It seems you have for more varieties/species of geranium on offer in the UK than we do here. For example, as common as it may be over there, I have never seen or heard of ‘Buxton’s Blue’. However, I will mention one geranium that is not on your list: G. maculatum, a North American native with lavender to white spring flowers. Does very well in shade. I’ve got quite a lot of it, along with ‘Rozanne’ and ‘Johnson’s Blue’.

    1. I’m glad you liked it – the flowers are a similar size and have a similar effect but make interesting contrasts in form and colour.

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