How to Grow Geraniums: Complete Care & Growing Guide

How to Grow Geraniums: Complete Care & Growing Guide

Geraniums are the undisputed champions of container gardening. With their bold, round flower clusters, aromatic foliage, and months-long bloom season, they have earned their place as one of the most popular flowering plants in the world. You will find them on windowsills in Paris, cascading from balcony boxes in Switzerland, and filling porch planters across North America.

What makes geraniums so beloved is their remarkable combination of beauty and toughness. They tolerate heat, resist most pests, and bloom continuously from late spring until the first hard frost with minimal fussing. Whether you are a first-time gardener looking for a reliable performer or an experienced grower seeking the perfect container plant, geraniums deliver.

This guide covers everything from choosing the right type to keeping your plants blooming their best all season long.

Quick Facts

Types of Geraniums: Which One Is Right for You?

The plants we commonly call geraniums are actually Pelargonium species, not true Geranium (cranesbill). Understanding the main types helps you choose the best variety for your growing situation.

Zonal Geraniums (Pelargonium x hortorum)

The most popular type and what most people picture when they think of geraniums. Named for the dark horseshoe-shaped zone on their rounded leaves. They produce large, ball-shaped flower clusters on upright stems and are the classic choice for containers, window boxes, and garden beds.

Best varieties: Maverick (compact, early blooming), Big Ezee (extra-large flowers), Calliope (heat-tolerant hybrid), Boldly (vigorous grower).

Ivy Geraniums (Pelargonium peltatum)

Trailing plants with glossy, ivy-shaped leaves that cascade beautifully from hanging baskets, window boxes, and elevated containers. Their flowers are slightly smaller than zonal types but bloom profusely. They prefer slightly cooler conditions than zonals.

Best varieties: Tornado (compact trailer), Temprano (early blooming), Great Balls of Fire (vigorous), Precision (weather-tolerant).

Scented Geraniums (Pelargonium spp.)

Grown primarily for their incredibly fragrant foliage rather than showy flowers. Crush a leaf and you might smell rose, lemon, mint, chocolate, apple, or dozens of other scents. The flowers are typically smaller and more delicate. Excellent for herb gardens, potpourri, and culinary use.

Best varieties: Citronella (lemon-scented, mosquito repellent claims), Attar of Roses (rose-scented), Chocolate Mint (chocolate-mint aroma), Apple (apple-scented, compact).

Regal Geraniums (Pelargonium x domesticum)

Also called Martha Washington geraniums. They produce the most spectacular, azalea-like flowers with ruffled petals and dramatic markings. However, they are more finicky than other types — they need cool nights (50-60°F) to bloom and do not tolerate summer heat well. Best for cool coastal climates or as spring-blooming indoor plants.

Best varieties: Elegance (large ruffled blooms), Aristo (bicolor patterns), Candy Flowers (compact habit).

Interspecific Hybrids (Calliope, Calienta, Boldly)

Modern crosses between zonal and ivy geraniums that combine the best traits of both: large upright flowers with trailing vigor, exceptional heat tolerance, and self-cleaning blooms. These are the best performers for hot summer climates and are increasingly the professional landscaper's choice.

True Geraniums vs. Pelargoniums: Clearing Up the Confusion

Common geraniums (Pelargonium) are tender perennials from South Africa with asymmetrical flowers and aromatic foliage. They are the subject of this guide.

True geraniums (Geranium spp.), also called cranesbills or hardy geraniums, are cold-hardy perennials native to temperate regions. They have symmetrical flowers, deeply lobed leaves, and spread as groundcovers. They are different plants with different care requirements.

When you buy "geraniums" at a garden center, you are almost always getting Pelargonium.

What You Will Need

Gather these supplies before planting:

• Geranium plants (nursery transplants or rooted cuttings)
• Containers with drainage holes (at least 8-10 inches in diameter per plant)
• Quality potting mix (well-draining, not heavy garden soil)
• Perlite (mix in 20% for extra drainage if needed)
• Balanced fertilizer (10-10-10 or 20-20-20 water-soluble)
• Slow-release granular fertilizer (optional, for set-and-forget feeding)
• Mulch (for garden bed plantings)
• Pruning shears or scissors (for deadheading and shaping)

Step-by-Step Growing Guide

1. When to Plant

Plant geraniums outdoors after all danger of frost has passed and nighttime temperatures stay consistently above 50°F. In most regions, this means:

• Zones 3-5: Late May to early June
• Zones 6-7: Mid to late April
• Zones 8-9: March to April
• Zones 10-11: Year-round (they grow as perennials)

You can start geraniums from seed indoors 12-16 weeks before the last frost date, but most gardeners buy nursery transplants because seed-grown geraniums take a long time to reach blooming size.

2. Choosing the Right Location

Geraniums need at least 6 hours of direct sunlight daily for the best blooming. In hot climates (Zones 8-9), they appreciate light afternoon shade to prevent heat stress.

• Morning sun + afternoon shade is the ideal combination in very hot regions
• Full sun all day works perfectly in Zones 3-7
• South or west-facing positions are best for containers on patios and balconies
• Ensure good air circulation — crowded, humid conditions promote disease

3. Soil Preparation

Geraniums are not fussy about soil but do demand one thing: good drainage. They will tolerate poor soil far better than wet feet. Root rot from waterlogged soil is the number one killer of geraniums.

For containers:

• Use a quality commercial potting mix (not garden soil, which compacts in pots)
• Mix in 20% perlite for extra drainage
• The pot MUST have drainage holes — no exceptions

For garden beds:

• Work 2-3 inches of compost into the top 8 inches of soil
• If your soil is heavy clay, add coarse sand or perlite
• Raised beds work excellently for geraniums in areas with dense soil

4. Planting

Container planting:

1. Fill pot with moistened potting mix to within 1 inch of the rim
2. Dig a hole the same depth as the nursery pot
3. Remove the plant gently and loosen any circling roots
4. Place at the same depth it was growing (do not bury the stem deeper)
5. Firm soil around the roots and water thoroughly
6. Space multiple plants 8-12 inches apart in large containers

Garden bed planting:

1. Dig holes 12 inches apart (closer for a fuller look, wider for better airflow)
2. Plant at the same depth as the nursery container
3. Water deeply after planting
4. Apply 1-2 inches of mulch around (not touching) the stems

5. Watering

This is where most geranium problems originate. The golden rule: water deeply, then let the soil dry out before watering again.

• Check before watering: Push your finger 1-2 inches into the soil. If it feels dry, water. If it is still moist, wait.
• Water at the base, not overhead. Wet foliage encourages botrytis (gray mold) and other fungal diseases.
• Containers: In hot weather, this may mean watering daily. In cool or cloudy weather, every 2-3 days.
• Garden beds: About 1 inch per week, adjusting for rainfall.
• Morning watering is best — it gives foliage time to dry before evening.

Signs of overwatering: Yellowing lower leaves, soft mushy stems, edema (corky bumps on leaves). Signs of underwatering: Wilting that does not recover in the evening, dry crispy leaf edges, reduced blooming.

6. Fertilizing

Geraniums are moderate to heavy feeders that reward consistent nutrition with more flowers.

• Water-soluble fertilizer (20-20-20 or 15-30-15): Apply every 2 weeks during active growth
• Slow-release granules (like Osmocote): Apply once at planting time for 3-4 months of feeding
• Bloom-boosting fertilizer (higher middle number, like 10-30-20): Use monthly to encourage more flowers
• Stop fertilizing 6-8 weeks before your first expected frost if you plan to overwinter plants

Avoid excess nitrogen (the first number in fertilizer ratios). Too much nitrogen produces lush foliage at the expense of flowers.

7. Deadheading for Continuous Blooms

Deadheading is the single most important thing you can do to keep geraniums blooming all season. When a flower cluster fades:

1. Trace the flower stem down to where it meets the main stem
2. Snap or cut the entire flower stem off at the base (not just the flower head)
3. Remove any yellowing or brown leaves at the same time
4. Do this every few days during peak bloom season

Some modern interspecific varieties (Calliope, Boldly) are self-cleaning and drop spent blooms on their own, but even these benefit from occasional grooming.

Overwintering Geraniums

In Zones 3-9, geraniums are killed by frost. But you can save your favorite plants for next year using one of these methods:

Method 1: Bring Indoors as Houseplants

The easiest approach. Before the first frost:

1. Dig up garden plants or bring containers inside
2. Cut back by about one-third
3. Place in a bright, sunny window (south-facing is ideal)
4. Water sparingly — every 1-2 weeks, letting soil dry between waterings
5. They will grow leggy and may drop leaves, but will survive
6. In spring, cut back again, increase watering, and move back outside after frost

Method 2: Bare-Root Dormant Storage

The traditional method used for generations:

1. Dig plants before frost, shake off soil, and hang upside down in a cool, dark place (45-50°F — an unheated garage, basement, or root cellar)
2. Once a month, soak the roots in water for an hour, then re-hang
3. In spring (6-8 weeks before last frost), pot up the shriveled plants, water well, and place in a sunny window
4. They will resprout from the thick stems. Not all will survive, but success rates of 70-80% are common.

Method 3: Take Cuttings in Fall

The most reliable method for preserving specific varieties:

1. Take 4-6 inch stem cuttings from healthy plants in September
2. Remove lower leaves, dip cut end in rooting hormone
3. Insert in moist perlite or seed-starting mix
4. Place in bright indirect light, keep moist but not wet
5. Roots develop in 3-4 weeks
6. Pot up rooted cuttings and grow on a sunny windowsill all winter
7. You will have strong, young plants ready for spring

Common Problems and Solutions

Yellowing Leaves

The most common geranium complaint. Lower leaves yellowing and dropping is usually overwatering — let soil dry out more between waterings. If upper leaves yellow between the veins while veins stay green, it is likely iron deficiency caused by alkaline soil. Apply chelated iron fertilizer or acidify the soil slightly.

Leggy, Stretched Growth

Caused by insufficient light. Move plants to a sunnier location. Pinch or cut back leggy stems to just above a leaf node to encourage bushy regrowth. For overwintered indoor plants, legginess is normal — prune hard in spring before moving outside.

No Flowers (Lots of Leaves)

Usually caused by too much nitrogen in the fertilizer, insufficient light, or not deadheading. Switch to a bloom-boosting fertilizer (higher phosphorus), ensure 6+ hours of direct sun, and remove spent flowers regularly.

Geranium Budworm (Tobacco Budworm)

Small caterpillars that bore into flower buds, causing them to fail to open or appear chewed. Look for tiny holes in buds and dark frass (droppings). Hand-pick caterpillars at dusk when they are active. For severe infestations, Bt (Bacillus thuringiensis) spray is effective and organic-safe. Choose light-colored geranium varieties (white, pink) — budworms strongly prefer dark red flowers.

Botrytis (Gray Mold)

Fuzzy gray mold on flowers and leaves, common in cool, humid conditions with poor air circulation. Remove affected parts immediately. Improve spacing, water at the base, and ensure good airflow. Avoid overhead watering.

Edema (Oedema)

Corky, blister-like bumps on the undersides of leaves. Caused by the plant absorbing water faster than it can transpire, usually from overwatering in cool, humid, low-light conditions. Not a disease — it is a physiological condition. Improve drainage, increase light, reduce watering frequency, and improve air circulation.

Rust

Orange-brown pustules on the undersides of leaves. Remove and destroy affected leaves. Avoid overhead watering. Improve air circulation. In severe cases, apply a fungicide labeled for rust on ornamentals.

Growing Geraniums from Cuttings

Propagating geraniums from cuttings is simple and the best way to duplicate a favorite plant:

1. Take cuttings in spring or early fall from healthy, non-flowering stems
2. Cut a 4-6 inch stem tip just below a leaf node
3. Remove lower leaves, leaving 2-3 leaves at the top
4. Let the cut end dry for a few hours (this reduces rot risk — geraniums are one of the few plants where this step matters)
5. Dip in rooting hormone (optional but improves success rate)
6. Insert in moist perlite, vermiculite, or seed-starting mix — about 2 inches deep
7. Place in bright indirect light (not direct sun)
8. Keep soil moist but not wet — mist lightly if needed
9. Roots develop in 2-4 weeks. Tug gently; resistance means roots have formed
10. Pot up in regular potting mix and gradually introduce to more sunlight

Success rate: 80-90% with healthy cuttings. Geraniums are among the easiest plants to propagate.

Companion Planting

Geraniums pair beautifully with many other plants:

• Petunias — complementary trailing habit in mixed containers
• Dusty miller — silver foliage contrasts gorgeously with red geraniums
• Sweet alyssum — low border plant that fills gaps and attracts beneficial insects
• Lobelia — blue flowers create a classic color combination with pink or red geraniums
• Herbs (basil, rosemary) — share similar sun and water needs
• Marigolds — both are heat-loving, pest-resistant summer workhorses

Avoid planting near: Heavy feeders that will compete for nutrients in containers, or shade-loving plants that cannot handle the full sun geraniums require.

Frequently Asked Questions

How often should I water geraniums?

Water geraniums when the top 1-2 inches of soil feels dry to the touch. In hot summer weather, container geraniums may need watering daily, while garden bed geraniums typically need about 1 inch per week. The most important rule is to let the soil dry slightly between waterings — geraniums handle short dry spells far better than constantly wet roots. Always water at the base of the plant rather than overhead to prevent fungal disease.

Why are my geranium leaves turning yellow?

The most common cause is overwatering. Geraniums prefer to dry out slightly between waterings, and consistently wet soil leads to root problems that show as yellowing lower leaves. Check your watering frequency and ensure your pot has drainage holes. Other causes include nutrient deficiency (feed regularly), natural aging of lower leaves (normal — just remove them), and sudden temperature changes.

Can I keep geraniums over winter?

Yes, there are three proven methods: (1) Bring them indoors as houseplants in a sunny window, cutting back by one-third and watering sparingly. (2) Store bare-root in a cool dark place at 45-50°F, soaking roots monthly. (3) Take cuttings in September, root them in perlite, and grow young plants on a windowsill all winter. Method 3 produces the healthiest plants for spring but requires more effort. Method 1 is easiest for beginners.

Are geraniums poisonous to dogs and cats?

Geraniums (Pelargonium) are considered mildly toxic to dogs and cats by the ASPCA. Ingesting the leaves or flowers can cause vomiting, depression, anorexia, and skin irritation (dermatitis). The essential oils in scented geraniums are more concentrated and potentially more irritating. While geraniums are unlikely to cause life-threatening reactions, keep them out of reach of pets who tend to chew on plants. If your pet ingests a significant amount, contact your veterinarian.

How do I make my geraniums bloom more?

Focus on these five factors: (1) Full sun — at least 6 hours daily. (2) Regular deadheading — snap off entire spent flower stems at the base every few days. (3) Proper fertilizing — use a bloom-boosting fertilizer (high phosphorus) every 2 weeks. (4) Avoid excess nitrogen — too much makes leaves at the expense of flowers. (5) Good drainage — stressed, waterlogged plants stop blooming. With these basics covered, healthy geraniums will bloom nonstop from spring through frost.