How to Grow Geraniums
Pelargonium × hortorum
Sun-loving, drought-tolerant South African tender perennials — the classic bedding and container flower.
By the Plants by Zone Editorial Team · Reviewed June 1, 2026
About geraniums
Despite the common name, zonal geraniums are Pelargoniums from South Africa, and their dry-summer origin explains their remarkable drought tolerance — overwatering is their primary killer. Boldly colored clusters of single or double flowers bloom steadily from late spring until hard frost on rounded, often horseshoe-patterned, fragrant leaves. They thrive in slightly dry, very well-drained soil and will even overwinter indoors to bloom again the following season.
When to plant and harvest geraniums
Timing is relative to your frost dates. Find your USDA zone for exact dates, or browse the month-by-month calendars.
Start seeds indoors
10–16 weeks before last frost (most gardeners buy transplants instead)
Transplant outdoors
After last frost, once nights are reliably above 50°F
Direct sow
Not practical — the season is too long; buy transplants or start indoors
Harvest
Deadhead spent flower clusters throughout summer to trigger continuous bloom
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How to grow geraniums step by step
- 1
Purchase nursery transplants for the easiest route, or start seeds on the surface at 70–75°F exactly 10–16 weeks before your last frost — germination is slow.
- 2
Transplant only after the last frost once nights are above 50°F; cold checks growth and yellows the leaves permanently.
- 3
Plant in very well-drained soil or containers, spacing 12–18 in apart.
- 4
Allow the top inch of soil to dry between waterings — more geraniums die from overwatering than from drought.
- 5
Deadhead spent flower clusters by snapping or cutting the stem cleanly at its base to keep new buds coming.
- 6
In late summer, take 3–4 in stem cuttings to root for indoor overwintering, or pot up whole plants before the first frost.
Common problems growing geraniums
⚠ Root rot (yellowing lower leaves, soft or blackened stems)
Almost always overwatering — let the soil dry partially between waterings, ensure drainage holes in containers, and never let pots sit in standing water.
⚠ Geranium budworm (distorted or shredded buds that fail to open)
A noctuid moth caterpillar bores into buds before they open. Hand-pick and destroy; apply Bt or spinosad spray at bud set as a preventive.
⚠ Botrytis gray mold on stems, leaves, or spent blooms
Remove dead leaves and deadhead promptly; improve airflow between plants and avoid wetting the foliage when watering.
⚠ Leggy plants with sparse bloom in late summer
Cut stems back by one-third and feed lightly with a balanced fertilizer; plants flush with new growth and rebloom as temperatures moderate.
✗ Keep away from
🧺 Harvesting geraniums
Deadhead by snapping or cutting each spent flower cluster where its stem meets the main stalk — leaving stubs invites botrytis. Remove yellowed leaves at the same time. For overwintering, take 3–4 in stem cuttings in late summer, strip the lower leaves, and root them in moist perlite under a bright window; cuttings overwinter more reliably than whole plants and root in 3–4 weeks.
Geraniums: frequently asked questions
When should you plant geraniums?＋
In most regions you start seeds indoors 10–16 weeks before last frost (most gardeners buy transplants instead), then transplant after last frost, once nights are reliably above 50°F. Timing is relative to your last frost, so find your USDA hardiness zone for the exact planting dates where you live.
Are geraniums and pelargoniums the same plant?＋
In the garden trade "geranium" nearly always means Pelargonium — a tender South African genus. True Geranium is a separate genus of mostly cold-hardy perennials (cranesbills). The mix-up dates to the 18th century and both names persist in catalogs, but horticulturally they are very different plants.
Can I overwinter my geraniums?＋
Yes. Take 3–4 in stem cuttings in late summer, root them in moist perlite or potting mix on a bright windowsill, and pot up once rooted. Alternatively, pot the whole plant before frost and keep it in a cool, sunny spot indoors at 45–50°F, cutting it back hard in late winter to re-energize it for spring.
Sources & review
Written and maintained by the Plants by Zone Editorial Team. Planting times are based on USDA hardiness zones and NOAA frost-date normals, with care guidance drawn from Cooperative Extension sources. Last reviewed June 1, 2026.
USDA Plant Hardiness Zone MapNOAA U.S. climate normalsCooperative Extension
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See exactly when to plant and what else to grow alongside geraniums, tailored to your USDA hardiness zone.
