Frequently asked questions


How many Campanula plants can I plant per square metre?

Depending on the variety, you can plant 5-9 plants per square metre of garden area. Adansa® varieties are a little wilder in their shape and growth, so it is best to leave a little more space between plants for this variety.

How big will Addenda® plants grow?

Campanula: Campanula is known as a perfect ground cover and border plant. The longer Campanula grows in the garden, the wider it will get in size. Campanula plants will not grow taller but remain about the same height as the time of purchase (about 20 cm). Occasionally Adansa® has a tendency to climb up against an adjacent tree or fence.

Hebe: can grow into a sizeable shrub of up to 50 cm if it keeps surviving winters. The size will depend on the pot size and variety you purchased. The Petita® variety stays small and compact, but Donna® varieties can grow quite large. You can prune every Hebe into shape every year in January and February.

When should I prune Addenda® plants?

There is no need to prune Hebe, but if you want to cut it into shape this is best done in January or February. You can prune Hebe back to about 15 cm above the soil, the plants will then develop new green shoots again in spring.

You don’t need to prune Campanula, just carefully remove the wilted flowers from time to time, but don’t cut off the branches.

How can I protect plants from frosts?

You can bring Hebe indoors, in a plant greenhouse, for example, or you can wrap the plants with frost-resistant cloth.

Campanula does not need to be protected from frosts; it will return every year after hibernating.

What is the best place for Hebe and Campanula in the garden?

Campanula loves a spot half in the sun, which you will probably easily find around the house. Campanula thrives in the open soil or a large plant border, which provide a good buffer for water and nutrition.

Hebe is a real sun lover, so put these plants in a spot in full sun or half sun.

What soil is best for growing Addenda® plants?

Campanula is an easy plant that will grow in any soil type, although it prefers calcareous soil. Hebe prefers airy, humus rich soil. A universal potting soil for garden plants or specifically for perennial plants will work well.


Are Addenda® plants perennial or annual?

The campanula plants from Addenda®, Ambella® and Adansa® are perennials. Campanula plants are hardy and can tolerate temperatures as low as -35 degrees Celsius.

While Addenda®’s Hebe plants are officially annuals, we know from experience that Addenda® Hebe tolerates wind and cold very well. Hebe can handle temperatures down to -3°C. If it gets any colder, bring the plants inside or wrap them in a protective cover. Since Dutch winters are often mild, Hebe can generally tolerate them well.

Will Campanula and Hebe bloom several times a year?

Absolutely! Campanula will take a short break after a 6-8 week flowering period before growing new flowers. Remove any wilted flowers and encourage the plant to flower more quickly.
Hebe will also continues to flower; regularly remove wilted flower plumes and the plant will keep growing new flowers.

Will Addenda® plants survive the winter?

Campanula is hardy. Hebe easily survives mild winters down to -3 °C. During severe frosts you should bring these plants inside or protect them.

What different types of Addenda® plants are available?

Discover and read all about the different Campanula and Hebe varieties on our product pages.

My Addenda® plant's leaves are turning yellow, what's wrong?

This can happen for a variety of reasons, but usually it has to do with too little or too much water.
For Campanula: feel the soil; if it is very wet, do not water the plants for a while. Feel with your finger every day. If the soil becomes a little dry, regularly give the plants a splash of water.

If the soil is bone dry, it means the Campanula has had far too little water. Chances are the plant will not survive this, so you might need to buy a new Campanula.

For Hebe: check that the Hebe plants are not too wet. Wet weather and a lack of sunshine can make Hebe more susceptible to fungus, and yellow leaves may then appear. If the plants are still partially green, it is best to prune them back in early spring to encourage new branches to grow.


Will Campanula spread?

Campanula is known as a perfect ground cover and border plant. The longer Campanula grows in the garden, the wider it will get in size. You will have faster results with the luscious Adansa®!

Can Campanula winter in a patio pot?

If you planted your Campanula in a patio pot, the Campanula will not get enough nutrition from the soil. Give the plant some extra plant food and plenty of water, otherwise it will come back less vigorously each year.

Can Campanula be placed indoors?

In early spring (January until the end of March) when it is still very cold outside in Northern Europe, Campanula will happily brighten up your living room with its flowers. After flowering, plant the plants in the garden or in a nice pot on your terrace and you will enjoy them for years to come.

Are bellflower and Campanula the same?

Campanula’s botanical name is the Latin word for ‘bell’. That is why Campanula is also known as bellflower.


Why are not all colours and varieties available on Addenda®.com?

Since our growers are located throughout Europe, we have selected two growers to handle the webshop orders for Addenda®.com for efficiency, speed and minimisation of transport movements.
However, all colours and different varieties are available at most garden centres and through other online channels. Go to sales points.

When can I buy Addenda® plants?

Campanula is available every year from February until the end of July.

Hebe is available every year from July until mid-October.

Where can I buy Addenda® plants?

Please visit our webshop or view the sales points for our Campanula and Hebe here.


Are Addenda® plants toxic to animals and people?

Absolutely not! In fact, they attract many insects. If you plant Campanula or Hebe in your garden or on your balcony, you will definitely get visits from bees and butterflies.

Are Addenda® plants sprayed with toxic chemicals?

We use plant protection products at Addenda® to produce quality plants. At Addenda®, we only use agents that are approved by the CTGB; these have been assessed for human, animal and environmental safety. We use green alternatives such as organic crop protection wherever possible. These agents are used to control pests such as weeds, fungi and bacteria, so we can deliver a healthy plant that can be enjoyed for many years. We structurally monitor the use of agents throughout the chain by means of residue analyses by independent labs at our growers and cuttings suppliers. Read more about our sustainability policy.

Does Addenda® use environmentally friendly packaging?

At Addenda®, we use recyclable materials and we reuse packaging. Read all about our recyclable and biodegradable packaging materials here.

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