Alvesgaspar / CC BY-SA 3.0
Geranium
Geranium nepalense
Overview
The term 'geranium' encompasses both true hardy geraniums (cranesbills) and the tender Pelargoniums commonly grown as annuals. Scented-leaf geraniums offer an astonishing range of fragrances including rose, lemon, mint, chocolate, and nutmeg, all from rubbing their aromatic foliage. Hardy cranesbills are tough, long-blooming ground covers, while Pelargoniums are classic window box and container plants.
Geranium (Geranium spp.) is a diverse genus of flowering plants that includes over 400 species. These perennial, biennial, or annual plants are native to temperate regions worldwide and the tropical mountain areas.
Members of Geranium typically feature opposite, simple leaves arranged in pairs along the stems. The leaves may be lobed or unlobed, with shapes ranging from rounded to deeply cut. Leaf sizes can vary significantly among species.
The flowers of Geranium plants are usually five-petaled and symmetric, appearing in various colors such as pink, purple, magenta, white, or red. They are arranged in terminal or axillary cymes, often forming a dense cluster. Flower sizes within the genus can range from small to quite large, depending on the specific species.
Geranium plants have a taproot system that allows them to anchor themselves well in the ground. The height of these plants varies greatly among species, with some growing as low as 3 inches (7.6 cm) and others reaching up to 3 feet (1 m) tall or more.
Growing Conditions and Care
These plants are known for their hardiness and adaptability to various environments. They can tolerate a wide range of soil types, from well-drained loams to sandy soils, as long as the conditions are not too waterlogged or excessively dry. The pH preference also varies among species but generally falls within the slightly acidic to neutral range.
Geranium plants are pollinated by insects and produce seeds that can remain viable in the soil for several years, allowing them to spread and naturalize in suitable habitats. Some species are considered invasive in certain areas due to their ability to establish themselves readily.
Growing Conditions
Habitat & Range
- Habitat
- Meadows & Open Areas
- Native Range
- Native to Indiana; also native to Afghanistan, Assam, China North-Central and 17 more regions; introduced in Illinois
- Cultivation Region
- Warm temperate to subtropical
Botanical data via projectGAIA.
Companion Planting & Soil
Good Companions
Sowing & Propagation
Planting Calendar
When to sow, transplant, and harvest by growing zone.
| Zone | Action | Months | Notes |
|---|---|---|---|
| Cold (1-2) | Start Indoors | Jan — Feb | Start indoors 12-14 weeks before last frost; slow grower from seed |
| Cold (1-2) | Transplant | Jun — Jun | Transplant after all frost; take cuttings in fall to overwinter indoors |
| Cold (1-2) | Bloom | Jun — Sep | Bloom until frost; remove faded flower clusters at base of stem |
| Cool (3-4) | Transplant | May — May | Transplant after last frost; deadhead regularly for continuous bloom |
| Cool (3-4) | Bloom | May — Oct | Long bloom; excellent on patios and balconies |
| Moderate (5-7) | Transplant | Apr — May | Transplant in spring; classic container, window box, and bedding plant |
| Moderate (5-7) | Bloom | Apr — Nov | Continuous bloom with deadheading; allow soil to dry between waterings |
| Warm (8-9) | Transplant | Mar — Apr | Plant in spring; may need afternoon shade in hottest areas |
| Warm (8-9) | Bloom | Mar — Jun | Spring bloom; may stall in summer heat then rebloom in fall |
| Warm (8-9) | Bloom | Sep — Dec | Fall rebloom |
| Hot (10+) | Transplant | Feb — Mar | Plant in early spring; or grow as fall/winter annual in hottest zones |
| Hot (10+) | Bloom | Oct — Apr (wraps) | Cool-season bloom; best fall through spring |
Uses
Culinary
- Scented-leaf varieties flavor cakes, jellies, and sugar
- Rose geranium leaves layered in cake pans for flavor
- Flowers used as edible garnish
Medicinal
- Rose geranium essential oil used for anxiety and skin care
- Traditional astringent for wound care and inflammation
- Aromatherapy for stress relief and hormonal balance
Other Uses
- Classic window box and container plant
- Scented varieties used as natural air fresheners
- Hardy cranesbills are excellent ground covers
