Geranium
Pelargonium × hortorum
Other names: Zonal geranium, garden geranium
Zonal geraniums are the familiar pot and window-box plants with rounded leaves and ball-shaped clusters of red, pink or white flowers. They bloom from spring to frost, tolerate some drought, and can be kept from year to year indoors.
How to grow geranium
Light
Give at least six hours of sun. In hot-summer regions, shade from the afternoon sun keeps plants flowering.
Watering
Water thoroughly, then let the top inch (2.5 cm) of mix dry. Geraniums rot if they are kept constantly wet.
Soil and feeding
Use a quality potting mix in containers with drainage holes. Feed every two weeks with a liquid fertilizer for flowering plants.
Planting and pruning
Plant outdoors after the last frost. Snap off faded flower stalks at the base and remove yellow leaves. Pinch long shoots to keep plants compact.
Propagation
Take 4 in (10 cm) stem-tip cuttings in late summer, remove the lower leaves and root them in gritty mix on a bright windowsill. Whole plants can also be potted up and kept indoors in a cool, bright room for winter.
Common problems
- Yellow lower leaves
- Overwatering or too little light.
- Gray, fuzzy mold on flowers and leaves
- Botrytis in cool, damp weather. Remove affected parts and improve air flow.
- Tall stems with few flowers
- Not enough sun, or the plant needs pinching back.
Questions about geranium
Are geraniums annuals or perennials?
They are perennials in frost-free climates (zones 10 to 11) and are grown as annuals or overwintered indoors everywhere else.
What is the difference between a geranium and a pelargonium?
The pot plants commonly called geraniums are botanically Pelargonium. True geraniums, known as cranesbills, are hardy garden perennials.
Plant details
| Botanical name | Pelargonium × hortorum |
|---|---|
| Family | Geraniaceae |
| Native range | Hybrid of South African species |
| Plant type | Annuals. Tender perennial grown as an annual |
| Soil | Fertile, free-draining potting mix |
| Flower color | Red, pink, white, orange |
