Geraniums are the workhorses of the container garden. The plants sold under that name at most nurseries belong to the Pelargonium genus, and they pump out color from late spring until frost with surprisingly little attention. Their rounded, kidney-shaped leaves often carry a darker zone or a pleasant scent, and blooms come in white, pink, red, orange, purple, and bi-colors. A pot of blooming geraniums anchors the front step whether the house is a modest bungalow or a sprawling mountain-style home with open living areas, and the same plants do double duty in window boxes and mixed borders.
Three species dominate garden center shelves: Pelargonium x hortorum, the zonal geraniums; Pelargonium peltatum, the ivy geraniums; and Pelargonium graveolens, the scented geraniums. They differ in growth habit, bloom size, and color, but all are grown as annuals in temperate zones and treated as herbaceous perennials in USDA zones 9 through 12. Full sun, organically rich soil, and regular deadheading cover most of their needs. One caution: geraniums are mildly toxic to dogs, cats, and horses, so keep them away from pets that nibble.
Choosing a Geranium Type That Fits Your Space
The first decision is which type to grow, because each fills a different role. Zonal geraniums stand upright, ivy geraniums trail, and scented geraniums earn their keep with fragrant foliage rather than flower power. Matching the plant to the container or bed position avoids the most common disappointment, a basket of stems that flops because the habit was wrong for the spot.
Zonal Geraniums (Pelargonium x hortorum)
Zonal geraniums are the classic bedding and window box plant, growing 1 to 3 feet tall and wide in a tidy, upright mound. The name comes from the horseshoe-shaped zone of darker pigment on each leaf. They take full sun, shrug off heat, and bloom in large clusters of red, pink, white, and orange, which makes them the most forgiving type for beginners.
Ivy Geraniums (Pelargonium peltatum)
Ivy geraniums have glossy, ivy-shaped leaves and a trailing habit that sends vines up to 5 feet long. They excel in hanging baskets, window boxes, and the front edge of large containers, where they spill over the rim. They prefer a little afternoon shade in hot climates and flower in softer tones of pink, lavender, and white. Gardeners who want trailing blooms for baskets and borders should start here rather than with the upright zonal types.
Scented Geraniums (Pelargonium graveolens)
Scented geraniums are grown mainly for their fragrant foliage, which releases notes of rose, lemon, mint, nutmeg, or apple when brushed. Their flowers are smaller and less showy than zonal or ivy types, but the leaves earn them a spot near a path or seating area, and they dry well for sachets and potpourri.
| Type | Growth Habit | Mature Size | Best Use |
|---|---|---|---|
| Zonal (P. x hortorum) | Upright mound | 1 to 3 ft tall and wide | Beds, window boxes, classic containers |
| Ivy (P. peltatum) | Trailing vines | Vines to 5 ft | Hanging baskets, container edges |
| Scented (P. graveolens) | Upright, loose | 1 to 3 ft tall and wide | Path edges, fragrance gardens |
Planting Geraniums Step by Step
Planting is straightforward, and the payoff comes from getting the basics right. Most geranium care guides agree that drainage failures kill more plants than any other mistake, so start with the right pot or bed and the right soil.
- Pick a spot with at least 6 hours of direct sun; part shade works in hot southern gardens, but the bloom count drops.
- Prepare organically rich, well-drained soil with a pH between 6.0 and 6.5, amending heavy clay with compost.
- Space zonal and scented geraniums 12 to 18 inches apart; give ivy geraniums about 24 inches so the vines have room.
- Set each plant at the same depth it grew in its nursery pot, because burying the crown invites stem rot.
- Water thoroughly at planting, then let the top inch of soil dry before watering again.
- Add a 1 to 2 inch layer of mulch in beds to keep roots cool and moisture even.
Container Planting vs. Garden Beds
Containers give you control over soil and sun and let you move plants to follow the light or shelter them from storms. Beds let plants grow larger and need less frequent watering once established. Either works; the choice usually comes down to space and style.
Pot Size and Drainage
Use a pot with drainage holes and a loose, peat-based potting mix. A single zonal geranium fills a 6 to 8 inch pot, while ivy geraniums in a 12 inch basket can trail a foot or more by midsummer. Empty saucers after heavy rain, because water left standing is the fastest way to rot roots.
Watering and Feeding for Continuous Blooms
Geraniums prefer a steady drink-and-dry rhythm. Check the soil with a finger and water when the top inch feels dry, deeply enough that liquid runs from the pot’s drainage holes. In containers that can mean daily watering during heat waves; in the ground, once or twice a week usually suffices.
How Much Water Geraniums Need
Overwatering is the more common failure. Soggy soil starves roots of oxygen and opens the door to rot, while brief dryness between waterings pushes plants to flower. Water at the base rather than overhead to keep foliage dry, and water in the morning so leaves dry before nightfall.
Feeding Schedule and Fertilizer Ratios
Feed container geraniums every 2 to 4 weeks with a balanced fertilizer diluted to half strength, or mix a slow-release granular product into the potting mix at planting. A 10-10-10 or 20-20-20 formula works well. Too much nitrogen produces soft, leafy growth and fewer flowers, so when in doubt, feed less.
When Geranium Leaves Turn Yellow
If geranium leaves turn yellow, work through the likely causes in order before reaching for fertilizer. The seven most common causes are easy to check and fix.
- Overwatering: yellow lower leaves with soft stems usually mean the soil never dries.
- Underwatering: leaves yellow and crisp at the edges when the plant has gone too dry.
- Nitrogen deficiency: older leaves pale first, and a balanced feed corrects it.
- Low light: plants stretch and yellow when they get less sun than they need.
- Temperature swings: cold drafts and sudden heat both stress leaves.
- Root-bound containers: a mat of roots that fills the pot cannot take up water evenly.
- Pests: aphids and spider mites drain sap and yellow the foliage they feed on.
Deadheading, Pruning, and Overwintering
Deadheading is the single highest-value task in geranium care. Removing spent blooms redirects energy into new flower buds, keeps the plant looking clean, and takes seconds per stem. A plant that is never deadheaded still blooms, but it blooms less and looks ragged by August.
Deadheading Basics
Snip each spent flower stem back to a leaf node or to the main stem rather than pulling the flower head alone, and work through the plant once a week during the main bloom period. If the plant gets leggy, shear the whole thing back by one-third in midsummer, trading a few weeks of bloom for a fresh flush.
Three Ways to Overwinter Geraniums
- Indoor windowsill: pot the plants up, give them bright light, and water when the top inch of soil dries.
- Dormant storage: dig plants up in fall, shake off the soil, and store the bare roots in a cool, dark spot.
- Cuttings: root a few stems in late summer and grow small plants indoors for spring.
Dormant Storage Details
For dormant storage, hang plants or wrap them loosely in paper and keep them at 45 to 55 degrees Fahrenheit, checking monthly. Soak the roots briefly every four to six weeks so they do not desiccate, then replant in fresh potting mix about six weeks before the last frost. Gardeners who keep seasonal care notes for plants such as daphne shrubs will find this routine far less demanding.
Propagating Geraniums from Cuttings and Seed
Growing geraniums from seed takes longer than rooting cuttings, but it lets you start dozens of plants for the price of a packet, and timing and temperatures matter more than technique. Cuttings, meanwhile, give you exact clones of a plant you already love.
Rooting Stem Cuttings
- Take 4 to 6 inch cuttings from healthy, non-flowering stems in late summer.
- Remove the lower leaves, leaving two or three at the top.
- Dip the cut end in rooting hormone if you have it; it speeds rooting but is not required.
- Insert the cuttings into moist perlite, vermiculite, or a light potting mix.
- Keep them in bright, indirect light and mist occasionally; roots form in 3 to 4 weeks.
Starting from Seed
Sow seed 10 to 12 weeks before the last frost date, planting 1/8 inch deep in moist seed-starting mix. Keep the flats at 70 to 75 degrees Fahrenheit and expect germination in 7 to 14 days. Move seedlings to individual pots once they have two sets of true leaves, then harden them off before setting them outside.
Pests, Problems, and a Seasonal Care Calendar
Healthy geraniums shrug off most pests, but a few insects find them worth the trouble. Geranium budworms eat flower buds from the inside, whiteflies gather under leaves, and aphids and spider mites appear when plants are stressed. Catch infestations early, when a stream of water or a few treatments still solves the problem.
Common Pests and Diseases
- Geranium budworm: small caterpillars that bore into buds; pick them off or treat with Bacillus thuringiensis.
- Whiteflies: tiny white insects that scatter when leaves are touched; sticky traps and insecticidal soap help.
- Aphids: cluster on new growth; wash them off with water or apply soap spray.
- Botrytis blight: gray mold on flowers and leaves in cool, wet weather; improve airflow and remove affected parts.
- Root rot: caused by poor drainage; repot in fresh mix and correct the watering schedule.
A Seasonal Care Calendar
A simple calendar keeps the work predictable. In spring, plant after the last frost and cut back overwintered plants. In summer, water, feed, and deadhead weekly. In early fall, take cuttings and decide which plants to bring in before the first frost. In winter, dormant plants rest in a cool spot while indoor plants grow slowly with less water. For a border that stays colorful from spring to frost, pair geraniums with easy shrubs such as azaleas, which carry the garden while young geraniums are still filling in.