Geranium

Geraniums (Pelargonium) are among the most versatile and forgiving bedding plants available. Purchase transplants in spring or start from cuttings taken the previous fall. Plant in full sun in well-drained soil or premium potting mix, spacing plants twelve to fifteen inches apart in beds or using one to three plants per twelve-inch container. Geraniums tolerate heat and moderate drought but perform best with consistent moisture.

Allow the soil to dry slightly between waterings, as geraniums are susceptible to stem rot in constantly wet conditions. Feed every two to three weeks with a balanced liquid fertilizer during the growing season. Deadhead spent flower clusters by snapping them off at the base of the stem to encourage continuous blooming and keep plants tidy.

Pinch growing tips on young plants to encourage bushy, compact growth and more flowering stems. In areas with hot summers, geraniums may slow their blooming during peak heat but rebound vigorously as temperatures cool in early fall. Before the first frost, bring container geraniums indoors to a sunny windowsill or take cuttings for winter propagation. Plants can also be overwintered dormant by hanging bare-root plants in a cool, dark basement and replanting in spring.

The garden geranium (Pelargonium) has its origins in the diverse flora of southern Africa, primarily the Cape Province of South Africa, where over 250 wild species thrive in the region's Mediterranean-like climate. Dutch and British traders first encountered these striking plants in the mid-1600s during their voyages around the Cape of Good Hope, and specimens began arriving at European botanical gardens by the 1630s. The earliest introductions included Pelargonium triste, prized for its fragrant nocturnal flowers, followed by Pelargonium zonale and Pelargonium inquinans, which would become the ancestors of the modern zonal geranium through extensive hybridization. Swedish botanist Carl Linnaeus originally grouped these plants with the true geraniums (Geranium) in 1753, but French botanist Charles Louis L'Héritier de Brutelle formally separated them into the distinct genus Pelargonium in 1789, based on differences in flower symmetry and seed structure. Despite this reclassification, the common name 'geranium' persisted in everyday usage. By the 1800s, Pelargoniums had become enormously popular across Europe, particularly in France, Germany, Switzerland, and Austria, where they adorned the iconic wooden window boxes of alpine chalets and village houses. Victorian-era plant breeders developed hundreds of cultivars, selecting for vivid flower colors, compact growth habits, and ornamental leaf patterns. The regal (Martha Washington) geraniums emerged from crosses involving Pelargonium cucullatum and Pelargonium grandiflorum, while the ivy-leaved types were derived from Pelargonium peltatum. In the 20th century, seed-grown F1 hybrid geraniums revolutionized commercial production, making these plants among the most widely sold bedding and container plants worldwide.

Geraniums prefer fertile, well-drained soil with a pH of 6.0 to 6.5. In containers, use a quality soilless potting mix with good drainage. Geraniums are moderate feeders that respond well to balanced liquid fertilizer applied every two to three weeks during active growth. Slow-release granular fertilizer mixed into container soil at planting reduces the need for frequent feeding. Avoid over-fertilizing, which produces lush foliage at the expense of flowers. Magnesium deficiency causes yellowing between leaf veins and is corrected with Epsom salt.

Geraniums are primarily enjoyed in the garden and containers rather than as cut flowers, though stems can be cut for small indoor bouquets. Cut when the first florets in a cluster have opened. Deadhead spent flower trusses regularly by snapping them off cleanly at the base of the flower stem. This is the single most important maintenance task for continuous blooming. Remove yellowing lower leaves to maintain an attractive appearance and prevent disease. For seed saving, allow a few seed pods to form and dry on the plant.

Geranium stems last only three to five days in water, so they are not ideal cut flowers. Their real value is their extended garden season. To overwinter geraniums, dig plants before frost, shake off soil, and hang upside down in a cool, dark basement at 45 to 50 degrees Fahrenheit. Mist roots monthly to prevent complete desiccation. In spring, repot in fresh soil, cut stems back to six inches, water, and place in bright light. Alternatively, take four-inch stem cuttings in late summer and root in moist perlite for fresh plants next spring.