- Species and varieties: Pelargonium, commonly known as geraniums, belong to the Geraniaceae family. There are numerous species and varieties of Pelargonium, including Pelargonium zonale (zonal geraniums), Pelargonium peltatum (ivy-leaved geraniums), and Pelargonium graveolens (scented geraniums). Hybrid varieties are often created to enhance specific traits such as flower color, size, and fragrance.
- Hybrid or heirloom: Pelargonium hybrid seeds are typically hybrid varieties. These hybrids are developed through selective breeding to combine desirable traits from different parent plants. Hybrid Pelargoniums are known for their vibrant colors, diverse flower forms, and improved resistance to diseases and pests. They are not considered heirloom varieties, which are open-pollinated and have been passed down through generations without significant alteration.
- Pruning and training: Regular deadheading of spent flowers encourages continuous blooming. Pruning can be done to shape the plant and promote bushier growth. Pinching back the stems can also help maintain a compact form. For ivy-leaved varieties, training them to climb or trail can enhance their ornamental appeal.
- Fertilization needs: Pelargonium hybrids 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 applied at the beginning of the growing season.
- Hardiness zones: Pelargonium hybrids are generally suitable for USDA hardiness zones 9-11. In these zones, they can be grown as perennials. In cooler climates, they are often grown as annuals or brought indoors during the winter months.
- Climate requirements: Pelargonium hybrids thrive in warm, sunny climates. They require full sun to partial shade and well-drained soil. These plants prefer temperatures between 60-75°F (15-24°C) and do not tolerate frost. In regions with hot summers, some afternoon shade can help prevent heat stress.