Flowers, Gardening, Grow Your Own, How To, Plants

How to Grow Calibrachoa


Presenting vivid displays of intricate blooms that last until the first frost, Calibrachoa (Million Bells) is a favourite amongst gardeners for keeping their outdoor spaces beautiful. Aside from being available in a range of shades, the cascading habit of this bedding plant makes it perfect for filling raised beds, hanging baskets, and containers. Wonderful for the beginner gardener, read on to discover the best tips on how to grow Calibrachoa.

Growing your Calibrachoa 


Depending on how much time and effort you are willing to sacrifice, you can either grow your Calibrachoa from seed, or purchase it as a young plug plant

Growing from Seed

An affordable way to introduce floral interest into your garden, growing Calibrachoa from seed won’t require any equipment that you don’t already have (a windowsill is perfectly sufficient). As long as you can provide the right conditions for your plants, you’ll be able to enjoy a flourishing display come summertime. With germination very easy, Calibrachoa is the perfect choice for a beginner gardener; the time between sowing and blooming spans as little as four months!

  • Fill an 8cm pot or half-size seed tray with compost, and smooth out the top with a flat-edged wooden block.
  • Gently tap the container, and firm down the soil. This will create an even base of fluffy compost.
  • Sprinkle a small layer of vermiculite over the compost, and thinly distribute your Calibrachoa seeds.
  • Provide them with a good watering, and move the container to a sunny windowsill. 
  • Try to keep the temperature above 20 degrees. Anything below this can prevent your seeds from germinating. Covering their container with a layer of cling film will help sustain this optimal condition.
  • It takes around 10 – 14 days for your Calibrachoa seeds to germinate. Once a stem with two small leaves has emerged, it’s safe to assume that germination has happened.
  • Now it’s time to  prick out your seedlings; which simply entails you planting them in a fresh container, ideally spaced one inch apart. If you prefer, you can assign each seedling their own individual pot. By this point, they will have reached a good enough size. 
  • You can prick out your seedlings by loosening their roots with a dibber, and carefully lifting them out of the soil. Take care to not handle them by their stem, as this can lead to bruising (which risks plant death).
  • Once your seedlings are around a month old, you can feed them with a starter solution/diluted fertiliser.
  • By this point, your seedlings are nearing the same stage of growth that a plug plant would be at. As such, the following steps are now applicable if you are growing Calibrachoa from shop-bought plug plants.
  • Before you plant your Calibrachoa in your garden, you should initially harden them off. This will accustom them to less predictable weather conditions and lower temperatures.
  • You can start by bringing them outside on milder days, and later opt for colder, breezier days. After around three weeks (and when there is no longer any danger of frost), they can safely be planted in your garden.

Planting Calibrachoa in your Garden


A tender perennial, your Calibrachoa will appreciate a site with organically rich soil that is moist but free-draining. It is important that you select a site that receives full sun or light shade. However, if you live in a warmer area, a little more shade can actually make your Calibrachoa survive for longer. Make of this what you will, but if you live in the United Kingdom, we still advise that you select a site that experiences at least six hours of sunshine a day.

Once you have chosen your site, begin preparing the soil by removing any stones or clumps of grass with a rake. Supplement the soil with compost, or alternatively top-soil with around 1 -2 inches of organic mulch.  Dig a hole that is large enough to accommodate the size of their rootball, and carefully firm down the surrounding soil. Your Calibrachoa plants should be spaced no less than six inches apart, but no more than twelve. Finish off the job with a generous watering.

Caring for your Calibrachoa


It is wisest to water your Calibrachoa in the morning, as this provides adequate time for the foliage to be dry in time for the evening; reducing the chance of disease. If possible, use a drip or trickle system which expels water at a low pressure near the soil.  The key is to keep your Calibrachoa’s soil moist, but never over-watered, as these perennials cannot cope with damp conditions. When new growth becomes visible, you can begin using a light fertiliser (too powerful a fertiliser can result in root-rot).

Conveniently, your Calibrachoa plants will drop any spent flowers naturally, and as such, you will not have to worry about dead-heading. Instead, simply enjoy the abundant display that your Calibrachoa has in store for the summer months.