What is a geranium?
Geranium (Pelargonium hortorum), commonly called the zonal geranium or garden geranium, is a tender perennial from South Africa grown worldwide as a bedding plant, patio container star, and sunny windowsill bloomer. Despite sharing a common name with the true Geranium genus (hardy cranesbills), these plants belong to the genus Pelargonium in the family Geraniaceae. They are prized for their long-lasting flower clusters in every shade of red, pink, salmon, white, and bicolor, combined with attractive rounded leaves that often show a darker “zone” across the middle.
How much light does a geranium need?
Geraniums are sun lovers — they need direct light to thrive and bloom. Outdoors they perform best in full sun (6+ hours). Brought inside, place them in the brightest window available, ideally south- or west-facing, where they receive at least 4–6 hours of direct sun. In lower light, stems stretch toward the light and bloom production falls off sharply. A supplemental grow light works well through winter to keep them compact and flowering.
How often should you water a geranium?
Water about every 1–2 weeks, waiting until the top inch or two of soil is dry before watering again. Geraniums are remarkably drought-tolerant — their thick stems store water — and they respond poorly to overwatering. Soggy roots quickly lead to root rot and yellowing leaves. When you do water, water thoroughly until it drains from the bottom, then let the pot dry before the next drink.
How do you keep geraniums blooming?
The key is deadheading — snapping or snipping off spent flower clusters all the way back to the main stem as soon as petals drop. Leaving old blooms on the plant signals it to slow flower production. Combine regular deadheading with full sun, a balanced slow-release fertilizer every 4–6 weeks during the growing season, and occasional light pruning to prevent legginess, and a healthy geranium blooms almost continuously from spring through autumn.
Can you overwinter a geranium indoors?
Yes. Before frost, bring container geraniums inside to a cool, bright room (55–65°F / 13–18°C). Water sparingly — just enough to keep the stems from shriveling — and let them rest. In late winter, cut back by one-third, increase watering, and move to the sunniest spot you have; they will flush out fresh growth and start blooming again in spring. This cycle can keep a single plant going for many years.
Are geraniums toxic to pets?
Yes — the ASPCA lists geraniums (Pelargonium species) as toxic to cats and dogs. The aromatic compounds geraniol and linalool can cause vomiting, loss of appetite, lethargy, and skin irritation if ingested or if the sap contacts skin. Keep plants on high shelves or in rooms pets cannot access.