- Species and varieties: Geraniums belong to the genus Pelargonium and are available in various species and varieties. Popular 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 flower seeds can be both hybrid and heirloom varieties. Hybrid geraniums are bred for specific traits such as disease resistance, uniform growth, and vibrant colors. 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 pruning is essential for maintaining the shape and health of geranium plants. Pinch back the growing tips to encourage bushier growth and remove spent flowers to promote continuous blooming. Pruning also helps prevent legginess and encourages new growth.
- Fertilization needs: Geraniums benefit from regular fertilization to support their growth and flowering. Use a balanced, water-soluble fertilizer with an N-P-K ratio of 10-10-10 or 20-20-20 every 4-6 weeks during the growing season. Avoid over-fertilizing, as this can lead to excessive foliage growth at the expense of flowers.
- Hardiness zones: Geraniums are typically grown as annuals in USDA hardiness zones 9-11. In these zones, they can be grown outdoors year-round. In cooler climates, geraniums are often grown as annuals or brought indoors during the winter months.
- Climate requirements: Geraniums thrive in warm, sunny climates with well-drained soil. They prefer temperatures between 65-75°F (18-24°C) during the day and slightly cooler temperatures at night. Geraniums require at least 6-8 hours of direct sunlight daily for optimal growth and flowering.