Seaside Petunia
Calibrachoa parvifloraUSDA | Grow Zone
9-11Outdoors all year in zones 9 to 11. Anywhere colder, keep it as a houseplant. Protect it below 40°F.
- Light
- Full sun, 6-8 hours
- Water
- When top inch is dry
- Humidity
- 40-60%
- Temperature
- 60-75°F
- Difficulty
- Intermediate
- Growth
- Moderate
- Mature size
- 12-18 in tall, 12-24 in wide
Calibrachoa parviflora, commonly known as Seaside Petunia, is a charming flowering plant native to South America. With its colorful blooms and trailing growth habit, it makes a stunning addition to hanging baskets and containers.
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Ideal temperature
60-75°F is where it grows fastest. Below 40°F cold damage starts.
Spacing and harvest
- Mature size
- 12-18 in tall, 12-24 in wide
- Plant apart
- 12-24 in
- Frost
- Half hardy: light frost only
Everything it needs
9 essentials at a glance
Watering
Calibrachoa parviflora prefers consistently moist soil but should not be waterlogged.
Water when the top inch of soil feels dry, typically every 2-3 days during the growing season. In hotter months, you may need to water daily. Signs of over-watering include yellowing leaves and root rot, while under-watering can cause wilting and browning leaf edges.
Light
This plant thrives in full sun, requiring at least 6-8 hours of direct sunlight daily.
Ideal placements include south-facing patios or gardens. While it can tolerate partial shade, too little light may result in leggy growth and fewer blooms.
Soil
Calibrachoa prefers well-draining soil with a pH range of 6.0 to 7.0.
A mix of potting soil, perlite, and compost is recommended to ensure good drainage. Avoid heavy soils that retain water, as this can lead to root rot.
Humidity
This plant enjoys moderate humidity levels around 40-60%.
To increase humidity, mist the leaves or place a humidifier nearby. Signs of low humidity stress include browning leaf tips and wilting.
Temperature
Calibrachoa thrives in temperatures between 60-75°F (15-24°C) and is hardy in zones 9-11.
It can tolerate brief periods of heat but should be protected from frost, which can damage the plant.
Fertilizing
Use a balanced, water-soluble fertilizer with an NPK ratio of 20-20-20 every 4-6 weeks during the growing season.
Reduce feeding in the fall and winter. Signs of nutrient deficiency include yellowing leaves and poor growth.
Pruning
Prune Calibrachoa in early spring to promote bushier growth and more blooms.
Use clean, sharp scissors to remove dead or leggy stems. Deadheading spent flowers can encourage new blooms and maintain a tidy appearance.
Repotting
Repot every 1-2 years or when the plant becomes root-bound.
Choose a pot that is 1-2 inches larger in diameter. Signs it needs repotting include roots growing out of the drainage holes and stunted growth. Carefully remove the plant from its pot, loosen the roots, and place it in fresh soil.
Propagation
Propagation can be done through stem cuttings or seeds.
For cuttings, take 3-4 inch stems from healthy plants in spring, remove lower leaves, and place in a moist potting mix. Keep in a warm, bright location until roots develop. Seeds can be sown indoors 8-10 weeks before the last frost.
When it's unhappy
Yellow leaves
Why it happens
Over-watering or nutrient deficiency.
How to fix it
Check soil moisture and reduce watering frequency. Fertilize with a balanced fertilizer to address nutrient deficiency.
Wilting
Why it happens
Under-watering or extreme heat.
How to fix it
Water the plant thoroughly and ensure it is not exposed to excessive heat. Adjust watering schedule as needed.
Root rot
Why it happens
Poor drainage or over-watering.
How to fix it
Ensure the pot has drainage holes and reduce watering frequency. If root rot is suspected, remove the plant from the pot, trim away affected roots, and repot in fresh soil.
Leggy growth
Why it happens
Insufficient light.
How to fix it
Move the plant to a brighter location where it can receive full sun for at least 6 hours a day.
Pest infestations (aphids, spider mites)
Why it happens
High humidity and poor air circulation.
How to fix it
Inspect plants regularly and treat infestations with insecticidal soap or neem oil. Improve air circulation around the plant.
Care through the year
Spring
In spring, prune back any dead or leggy growth and fertilize to promote new growth. Ensure the plant is in a sunny location as temperatures warm.
Summer
During summer, water regularly and check for pests. Deadhead spent flowers to encourage continuous blooming and maintain a tidy appearance.
Fall
In fall, gradually reduce watering as temperatures drop. Continue to deadhead and prepare the plant for cooler weather by moving it indoors if necessary.
Winter
In winter, reduce watering significantly and keep the plant in a cool, bright location. Protect from frost and avoid fertilizing during this dormant period.
Toxicity & Safety
Calibrachoa is generally considered non-toxic to pets and children. However, ingestion of large quantities may cause mild gastrointestinal upset. It is always best to keep plants out of reach of curious pets.
Good to know
Why are my Seaside Petunia leaves turning yellow?
Yellow leaves on Calibrachoa can indicate over-watering or a nutrient deficiency. Check the soil moisture and adjust your watering schedule accordingly.
How often should I water my Calibrachoa?
Water your Calibrachoa every 2-3 days, allowing the top inch of soil to dry out between waterings. In hotter months, daily watering may be necessary.
Can I grow Calibrachoa in partial shade?
While Calibrachoa prefers full sun, it can tolerate partial shade. However, too little light may result in leggy growth and fewer flowers.
How do I propagate Seaside Petunia?
You can propagate Calibrachoa through stem cuttings or seeds. For cuttings, take healthy stems in spring and root them in a moist potting mix.
What is the best fertilizer for Calibrachoa?
A balanced, water-soluble fertilizer with an NPK ratio of 20-20-20 is ideal. Fertilize every 4-6 weeks during the growing season for optimal growth.
How do I prevent root rot in my Calibrachoa?
To prevent root rot, ensure your pot has adequate drainage and avoid over-watering. Allow the top inch of soil to dry out before watering again.
When should I prune my Seaside Petunia?
Prune Calibrachoa in early spring to encourage bushier growth and more blooms. Remove dead or leggy stems to maintain a healthy appearance.
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