Calibrachoa, often called “million bells,” packs a punch with nonstop color and trailing beauty. These sun-loving stunners are a container gardener’s dream—if you know how to treat them right.
From planting secrets to bloom-boosting care, these 17 brilliant tips will help you grow calibrachoa that turns heads all season long.
1. Choose The Right Location
Calibrachoa thrives in spots that receive at least 6-8 hours of direct sunlight daily. Morning sun with afternoon shade works well in hotter climates to prevent wilting during scorching summer days.
Place your containers where you can enjoy their colorful display but also where they’ll get proper light. A sunny patio, balcony edge, or window box makes an ideal home for these flowering beauties.
2. Select Quality Potting Mix
Never use garden soil for your calibrachoa! These plants demand well-draining, high-quality potting mix specifically formulated for containers. Garden soil compacts too easily and retains excess moisture that leads to root rot.
Look for mixes containing perlite or vermiculite that improve drainage while retaining just enough moisture. Some gardeners add a handful of sand to further enhance drainage, especially in humid climates.
3. Plant In Proper Containers
Calibrachoa’s trailing habit shines in hanging baskets, window boxes, and elevated planters where stems can cascade dramatically. The container should have ample drainage holes – this isn’t negotiable!
Size matters too. While these plants aren’t massive, they need room for root development. Choose containers at least 10-12 inches in diameter for multiple plants, allowing about 6-8 inches between each one when planting.
4. Master Watering Techniques
Calibrachoa requires consistent moisture without becoming waterlogged. Water thoroughly when the top inch of soil feels dry, allowing excess to drain completely. During peak summer heat, daily watering might be necessary.
Morning watering gives plants time to dry before evening, reducing disease risk. Avoid overhead watering which can damage delicate blooms – instead, direct water at the soil level. Wilting during midday heat is normal, but if plants remain wilted into evening, they need a drink!
5. Fertilize Regularly
Hungry feeders by nature, calibrachoa needs consistent nutrition for continuous blooming. Apply water-soluble fertilizer formulated for flowering plants every 7-10 days at half strength, rather than full strength less frequently.
Slow-release fertilizer pellets work well as a supplement but shouldn’t be your only feeding method. Yellow leaves often signal nutrient deficiency, particularly iron. If this occurs despite regular feeding, try an iron supplement or acidifying fertilizer.
6. Prevent Common Diseases
Root rot presents the biggest threat to calibrachoa health. Prevention starts with proper drainage and avoiding overwatering. If leaves yellow from the bottom up, you might be dealing with early root problems.
Powdery mildew can appear during humid weather as white powdery patches on foliage. Improve air circulation by proper spacing and remove affected parts promptly. Fungicides specifically labeled for ornamentals can help in severe cases.
7. Deal With Pest Problems
Aphids love calibrachoa’s tender new growth. These tiny green or black insects cluster on stems and buds, sucking plant juices. A strong spray of water often dislodges them, or try insecticidal soap for heavier infestations.
Spider mites become problematic during hot, dry weather, creating fine webbing between leaves. Increase humidity around plants by misting regularly. Whiteflies might also appear – yellow sticky traps help monitor and reduce their populations without harsh chemicals.
8. Perfect Your Pruning Approach
Light pruning encourages bushier growth and more flowers. When stems grow leggy with fewer blooms, snip them back by one-third using clean scissors or pruning shears.
Don’t be afraid to cut! Calibrachoa responds well to trimming, especially mid-season when growth might slow. Remove spent flowers regularly if your variety doesn’t self-clean. For overwintered plants, cut back dramatically in early spring before new growth emerges.
9. Combine With Complementary Plants
Calibrachoa plays well with others in mixed containers. Pair with upright plants like geraniums or spiky dracaena for height contrast. Sweet potato vine makes an excellent companion, its larger leaves complementing calibrachoa’s small blooms.
Consider color combinations carefully. Purple calibrachoa pops against chartreuse sweet potato vine, while pink varieties harmonize beautifully with silver-leaved plants like dusty miller. For monochromatic drama, try different calibrachoa colors from the same family.
10. Extend The Blooming Season
Deadheading isn’t necessary with most modern calibrachoa varieties as they’re self-cleaning. However, if blooming slows, a light overall trim stimulates fresh flowers. Removing spent blooms on older varieties helps maintain appearance.
To push blooming into fall, increase phosphorus with a bloom-boosting fertilizer in late summer. In mild climates, calibrachoa can flower until first frost with proper care. Moving containers to sheltered locations during cool nights extends the season even further.
11. Manage Temperature Extremes
While heat-tolerant, calibrachoa struggles when temperatures consistently exceed 90°F. During heatwaves, move containers to morning-sun-only locations and increase watering frequency. Adding mulch on the soil surface helps retain moisture.
Cold tolerance varies by variety, but most calibrachoa suffer below 35°F. In borderline climates, protect plants on chilly nights by moving containers against the house wall or under overhangs. For unexpected frosts, cover with lightweight fabric overnight.
12. Address Nutrient Deficiencies
Iron chlorosis appears as yellowing leaves with green veins, particularly in alkaline conditions. Apply chelated iron according to package directions to correct this common issue. Magnesium deficiency shows as yellowing between leaf veins.
For quick fixes, foliar sprays work faster than soil applications. A tablespoon of Epsom salts dissolved in a gallon of water makes an effective magnesium supplement when sprayed on leaves. Always apply nutrient corrections in early morning or evening to prevent leaf burn.
13. Propagate New Plants
Creating new calibrachoa plants from cuttings saves money and preserves favorite varieties. Take 3-4 inch stem cuttings just below a leaf node during spring or early summer. Remove lower leaves and dip the cut end in rooting hormone powder.
Plant cuttings in moist potting mix, covering with clear plastic to maintain humidity. Place in bright, indirect light and roots should develop within 2-3 weeks. Hybrid varieties won’t come true from seed, making cuttings the reliable propagation method.
14. Overwinter Successfully
Calibrachoa can survive winter in frost-free areas (USDA zones 9-11) as perennials. In colder regions, bring containers indoors before first frost and place in a cool, bright location around 50-60°F. Reduce watering significantly, allowing soil to nearly dry between light waterings.
Prune plants back by half to reduce stress and conserve energy. Don’t fertilize during winter rest period. Watch for pests like aphids which love indoor conditions. Come spring, gradually reintroduce plants to outdoor conditions before permanent placement.
15. Maintain Proper pH Levels
Calibrachoa prefers slightly acidic soil with pH between 5.5-6.2. Higher pH levels block nutrient absorption, particularly iron, causing yellowing leaves despite regular fertilizing. Test soil pH with an inexpensive kit from garden centers.
If pH rises above 6.5, acidify soil using products like soil sulfur or aluminum sulfate following package directions. For quick fixes, water occasionally with a solution of 1 tablespoon white vinegar per gallon of water. Avoid using alkaline municipal water when possible.
16. Troubleshoot Common Growth Issues
Leggy growth with few flowers usually indicates insufficient light. Move containers to sunnier locations or prune back stretched stems to encourage bushier growth. Leaf drop from lower stems often signals overwatering – allow soil to dry more between waterings.
Flower production slowing mid-season? This typically means it’s time for fertilizer refreshment. Stunted growth with dark green leaves suggests phosphorus deficiency – switch to a bloom-boosting fertilizer with higher middle number in the NPK ratio.
17. Choose The Best Varieties
Superbells® series offers exceptional heat tolerance and self-cleaning habits. Cabaret® varieties feature larger flowers and excellent disease resistance. For smaller spaces, try MiniFamous® compact types that stay under 6 inches tall.
Color options seem endless! Traditional pinks and purples perform reliably, while newer yellow and orange varieties need extra sun for best color development. Two-toned varieties like ‘Tequila Sunrise’ create dramatic displays but may need slightly more fertilizer to maintain their complex coloration.