You’ll also hear this plant called bellflower, alluding to the bell shape the flowers take before opening. When they do eventually open, they reveal enticing star-shapes, making Campanula a pleasure to look at throughout the year.
We’ve written this Campanula growing guide to help you get started with a Campanula plant in your garden. By the time you finish, you’ll know which right variety is right for you, and how to ensure strong and confident growth.
What is Campanula?
Technically speaking, the term Campanula refers to plants from the family Campanulaceae that are known as bellflower. Other plants from the family include lady bells, harebells, and hundreds more.
Campanula plants have a lot of versatility. Some are deciduous, while others are evergreen. Some are bushy, while others form clumps. You can find annual, biennial, and perennial varieties, ranging in size from 5cm to over 2 meters. None of the plants in this guide reaches quite that height, but more on that later.
What types of Campanula are there?
You’ll see three main types of Campanula: Poscharskyana, lactiflora, and glomerata. The names, respectively, mean trailing, milky, and clustered.
As we said, there are hundreds of types of this plant. There’s not enough space in this guide to introduce them all, so we’ve selected eight varieties that have each received the Royal Horticultural Society Award of Garden Merit, as well as its Plants for Pollinators Award.
This means that choosing a variety from this list should guarantee a plant that will grow particularly well in a British garden. It will attract bees and butterflies, too, bringing additional life and colour to your garden.
This clustered bellflower variety lives up to its name, bringing superb splashes of blue and purple in the summer. Its proud bushels will look exceptional standing alone, or integrated into a floral display with other types and colour. Expect an ultimate height of about half a metre and a spread around a metre.
This is a milky type, so-called because its colours are a bit paler, and fade slightly into white toward the middle of the flower. If you’re looking for something a bit more delicate than the bold, confident colours of other varieties, Favourite could be for you.
This variety – also known as American harebell or Carpathian bellflower – lends itself excellent to rock displays and borders that get a lot of sunlight. You can expect vibrant purple, and an overall size slightly smaller than Superba, clocking in around half a metre square.
A clustered variety, Caroline spreads wide – up to a metre – and its flowers grow upward from the mat of leaves. The overall effect is quite charming, and the pinky-purple colour palette makes this variety an eye-catching presence in any garden. It works well in flower borders and other low-maintenance areas.
Another milky variety, Alba boasts sparkling white flowers that grow to an impressive height of around 1.5 metres – making this the tallest variety in our list. The RHS note that Alba is particularly suited to underplanting roses and other shrubs, as it provides an attractive backdrop for them to grow against.
This milky variety features gentle pink leaves that fade into white, bringing a slightly different nuance of colour to the others we’ve in our list. Its beautiful colours combined with long, elegant stems (expect a height of around 1.5m) make Loddon Anna a popular variety for gardeners of all abilities.
This variety is a widespread presence at stately homes and other such impressive settings, thanks to its regal aesthetic. White, violet and blue mingle beautifully on its flowers, which grow in large and inviting clumps. Growing up to a metre in height, a bush of Prichard’s Variety is an easy way to bring sophistication and stateliness into your garden.
As the only poscharskyana – trailing bellflower – in our list, Stella sports violet-blue, star-shaped flowers that look simply fantastic. You can expect a mound about 0.5m wide by 10cm high – much shorter than many other varieties, and offering different possibilities in terms of placement and combinations.
There are other varieties of Campanula poscharskyana. Frost, for example, has attractive white flowers, and a similar growth profile.
Introducing a Campanula into your garden
Campanula is a relatively easy plant to introduce to a British garden. Its growing conditions are not particularly fussy, so as long as you take a bit of time to understand the best time and place to plant it out, you should be good to go.
It’s very hardy, too. All the varieties we featured in this list are between 5 and 7 on the RHS hardiness scale. This means they range from “hardy in most places throughout the UK even in severe winters” through to “hardy in the severest European continental climates.”
For the vast majority of British gardeners, temperatures will never dip below those that a Campanula will struggle with.
What soil does Campanula need?
Chalky, loamy soil suit all varieties of bellflower. Some types will take to soil with sand or chalk present, too.
All varieties can grow in alkaline or neutral soil, and a few can tolerate mild acidity.
In terms of drainage, this plant prefers moist but well-drained soil. Particularly sensitive varieties will require well-drained soil, but these are in the minority. Check the RHS plant database for the specific criteria of each variety.
Where to plant your Campanula
There is no hard-and-fast rule for where to plant a bellflower. Some types – like Stella – like exposure. Others (Loddon Anna, Prichard’s Variety) prefer shelter. Others, still, can thrive in either condition.
Because of this, different varieties prefer different aspects. The selection we included above, for example, run the range of favouring North, West, South, and East.
There is one trait all bellflowers share, however: None will thrive in full shade.
We recommend checking the RHS plant database or other information to find the specific needs for the variety you’re looking to grow.
When to plant your Campanula
The best time to plant bellflower is spring, once the soil has started to warm after winter. To give your plants a head start you can grow them in seed trays, beginning a few weeks before the last frost is expected.
Planting out your Campanula
If you’re planting seeds directly into the garden, use a dibber to create a hole a couple of centimetres deep. Water thoroughly and stay attentive until seedlings start to appear.
Planting from a division is easy, too: Just dig a hole large enough for the plant and its root system, place it in, and cover it over. Make sure it is planted at the same depth as previously because planting too deep can cause damage.
You can propagate most varieties of Campanula by division in spring and autumn, or by basal cuttings in spring. From the list above, Carpatica can be propagated by seed.
It’s good to divide your plants every three years or so to prevent overcrowding. To do this, gently dig it up and pull the roots apart, either by hand or with the careful use of a knife, spade, or similarly sharp implement.
Bellflower responds well to a bit of compost in spring, then again in mid-summer. You can use organic or non-organic, just make sure you water thoroughly after each dressing.
Mulching around the base of your plant will strengthen growth and maintain healthy soil conditions. Leave a couple of inches diameter around stems.
How to prune your Campanula
Pruning requirements differ between bellflower varieties. With some – like the Carpatica – you don’t need to prune at all. Others (Stella) need to be cut back after flowering to maintain their optimum shape. Pruning other varieties will prevent them self-seeding, and will encourage a second wave of flowers after the first wave begins to dwindle.
Protecting your Campanula from pests and diseases
You can minimise the likelihood of your plant contracting most diseases by keeping it generally healthy. This means:
- Keeping the soil well-watered, so the plant has moisture.
- Keeping the soil well-drained, so the plant doesn’t have too much moisture.
- Ensure enough access to sunlight.
- Leave space between plants to reduce density and overcrowding.
- Don’t use too much nitrogen in your fertiliser.
Slugs and snails
No one likes slugs or snails, but sadly they like pretty much every plant in your garden.
Both are active year-round and will munch unsightly holes in the leaves and stems of your bellflower plant. Keeping them at bay is the goal of all gardeners, but their prevalence makes it an ongoing job.
You can use products like Nemaslug to target both. Other gardeners create barriers of crushed up eggshell or attempt to make beer traps that will lure in and drown slugs and snails before they damage your garden. If you find these creatures and aren’t feeling squeamish, you can freeze them in your freezer, then add them to your compost pile.
Another ubiquitous garden pest, aphids suck sap from plants they infest. This drainage hinders plant growth and can lead to eventual plant death.
They’re visible to the naked eye, so scanning your Campanula occasionally offers protection from unexpected infestation. You may also see symptoms of their sucking, first: Curled or distorted leaves, black sooty moulds, and generally poor health.
Other less pestilent bugs can keep aphids at bay, and at certain times of the year, this removes the need for any other intervention. If it’s the wrong time of year or you don’t trust these other bugs to keep things in check, pesticides can be deployed.
If you find a coating of white dusty powder on the leaves of you Campanula, it may be a victim of powdery mildews. This disease is called by fungal infection, and although many plants are susceptible, it’s interesting to note that the fungus is different in each case.
The best way to prevent infection is to destroy infected leaves when they fall from the plant. This will get rid of the spores that cause infection, as will pruning out shoots that are infected. Various pesticides are available, too.
Keeping the plant healthy will reduce the risk of powdery mildews.
This is a very common garden disease which will reduce your plant’s vitality, then, if left unchecked, gradually kill it off. As with powdery mildews, this is caused by a fungal infection. It can affect leaves, stems, or flowers – so keep a careful eye on your whole Campanula plant.
You’re looking for pale spots or pustules, which indicate the production of spores. They vary in colour. Some are rust coloured, hence the name. Others range from yellow to brown to black.
Removing affected leaves can help keep early infection at bay, but if you remove too many you’ll damage your plant. If things have progressed to this stage, fungicides can be used to prevent further spread. Make sure not to compost any infected material, as the spores are durable and may infect other parts of your garden.
Bellflower of the Ball
Whether you use the Latin name Campanula or the more colloquial bellflower, this plant will bring a lot to your garden. It’s pretty, colourful, and versatile. It’s hardy against the elements and fairly resistant to pests. In short, you’ll be getting a lot of bang for your gardening buck.
The goal of this guide is to give you all the info you need to get the plant thriving in your garden, whatever your level of experience. We hope you find the guide useful.