- Species and varieties: Geraniums belong to the genus Pelargonium and are available in various species and varieties. Common species include Pelargonium zonale (zonal geraniums), Pelargonium peltatum (ivy-leaved geraniums), and Pelargonium graveolens (scented geraniums). Each species has numerous cultivars with different flower colors, leaf shapes, and growth habits.
- Hybrid or heirloom: Geranium seeds can be both hybrid and heirloom varieties. Hybrid geraniums are bred for specific traits such as disease resistance, flower color, and growth habit. Heirloom geraniums are open-pollinated and have been passed down through generations, often valued for their unique characteristics and historical significance.
- Pruning and training: Regular deadheading (removal of spent flowers) is essential to encourage continuous blooming. Pruning can help maintain a compact shape and promote bushier growth. Pinching back the stems can also encourage branching and more flowers.
- Fertilization needs: Geraniums benefit from regular fertilization. Use a balanced, water-soluble fertilizer every 2-4 weeks during the growing season. Avoid over-fertilizing, as this can lead to excessive foliage growth at the expense of flowers. A slow-release fertilizer can also be used at the beginning of the growing season.
- Hardiness zones: Geraniums are typically grown as annuals in USDA hardiness zones 9-11. In cooler climates, they are often grown as annuals or brought indoors during the winter months.
- Climate requirements: Geraniums thrive in warm, sunny conditions with well-drained soil. They prefer temperatures between 65-75°F (18-24°C) during the day and slightly cooler temperatures at night. They require at least 6 hours of direct sunlight daily for optimal growth and flowering.