Growing Regal Geraniums: The Complete Guide

1. Understanding Regal Geraniums

Regal geraniums are hybrids bred for their extravagant flowers, which often feature bold bi-colored petals and intricate markings. Unlike the common zonal geranium, regals prefer cooler growing conditions and bloom most heavily in spring and early summer.

Key traits:

Botanical name: Pelargonium × domesticum

Bloom period: Late winter to late spring (indoors) or spring to early summer (outdoors).

Height & spread: 12–24 inches tall and wide.

Fragrance: Mild scent in leaves when crushed.


2. Choosing How to Grow Them

You can start regal geraniums from:

Nursery plants (most common).

Cuttings from an existing plant.

Seeds (less common — hybrids may not come true to type).


3. Ideal Planting Time

Outdoors: Plant after the last frost date in your area.

Indoors: Can be started at any time with adequate light.

In most climates, they are treated as annuals, but in frost-free regions (USDA zones 10–11), they can be grown year-round.


4. Light Requirements

Indoors: Bright, indirect light; a south- or west-facing window is ideal.

Outdoors: Full sun to light afternoon shade; too much intense midday sun can scorch flowers and leaves.


5. Soil Preparation

Regal geraniums thrive in loose, well-draining soil.

For containers:

Use high-quality potting mix with added perlite or coarse sand.

Avoid heavy garden soil, which holds too much moisture.

For garden beds:

Amend with compost and grit for drainage.

Aim for a pH between 6.0 and 6.5.


6. Planting in Pots

Choose a 12–14 inch container with drainage holes.

Fill with potting mix, leaving 2 inches at the top.

Plant so the crown is at soil level.

Water lightly to settle soil.


7. Watering Needs

Regal geraniums dislike soggy soil but also shouldn’t dry out completely during bloom.

During active growth: Water when the top inch of soil feels dry.

After flowering: Reduce watering as plants rest.

Container tip: Check daily in hot weather, as pots dry faster.

Always water at the base to avoid wetting foliage, which can lead to fungal problems.


8. Fertilizing Schedule

Feed every 2 weeks during the blooming season with a high-phosphorus fertilizer (e.g., 10-20-10) to promote flowers.

Stop fertilizing after the bloom period ends to allow the plant to rest.


9. Temperature & Humidity

Best bloom temperature: 60–70°F (15–21°C) during the day and 50–55°F (10–13°C) at night.

Hot weather can halt blooming; in summer, move containers to a cooler, shaded location if possible.

Avoid overly humid areas, which can encourage disease.


10. Deadheading & Pruning

Deadhead spent blooms promptly to encourage new buds.

Remove yellowing leaves regularly to improve airflow.

After blooming, cut back stems by one-third to maintain shape and encourage bushy growth.


11. Pest & Disease Prevention

Common pests:

  • Aphids
  • Whiteflies
  • Spider mites

Common diseases:

  • Botrytis (gray mold)
  • Root rot (from overwatering)
  • Rust

Prevention tips:

  • Provide good airflow.
  • Water early in the day.
  • Use insecticidal soap or neem oil for pests.

12. Encouraging a Full, Dome Shape Like in Your Photo

Pinch back stem tips regularly in early growth to encourage branching.

Rotate the pot weekly so all sides receive equal light.

Avoid overcrowding; one plant per medium pot gives best results.


13. Blooming Cycle & Rest Period

Regal geraniums naturally bloom in spring and early summer. After flowering:

Reduce watering.

Keep in a cool location (50–55°F) for 6–8 weeks.

Resume normal care to trigger a second bloom cycle in cooler weather.


14. Overwintering

If you live in a frost-prone area:

Bring pots indoors before the first frost.

Place in a bright, cool location.

Water sparingly until spring growth resumes.


15. Propagation by Cuttings

In late summer, cut 4–6 inch non-flowering shoots.

Remove lower leaves and dip the cut end in rooting hormone.

Plant in moist, sterile potting mix.

Keep in bright, indirect light until rooted (about 4–6 weeks).


16. Design & Companion Ideas

Pair regal geraniums with plants that like similar conditions:

  • Lobelia
  • Petunias
  • Verbena

Their upright, domed form makes them perfect as a container centerpiece or in window boxes.


17. Annual Care Calendar for Regal Geraniums

January–February

  • Indoors: Maintain cool temps and bright light.
  • Check for pests.

March–April

  • Begin fertilizing.
  • Move pots outdoors after frost danger passes.

May–June

  • Peak bloom period; deadhead often.

July–August

  • Move to a cooler, shaded location if heat is intense.

September–October

  • Take cuttings for next year.
  • Begin reducing water.

November–December

  • Overwinter indoors in cool, bright location.

🌟 Final Tips

Regal geraniums are not heat lovers, so their spectacular blooms are best in spring-like conditions.

The lush dome shape in your photo comes from consistent pinching, even light, and no overcrowding.

Treat them as seasonal showpieces — a few months of stunning flowers, followed by rest and careful maintenance, can give you years of beauty.

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