Regal geraniums (Pelargonium x domesticum)

Regal geraniums (Pelargonium × domesticum) are a group of hybrid geraniums characterized by large, showy flowers and elegant appearance. Regal geraniums originate from hybridization involving Pelargonium grandiflorum and Pelargonium cucullatum. Also referred to as Martha Washington geraniums are suitable for various garden settings, including flower beds, borders, containers, and hanging baskets. They also make excellent additions to indoor spaces. The plant can live for several years under the right conditions.

Physical Characteristics and facts

  • The leaves are deeply lobed or serrated, giving them an ornate appearance. The leaves are usually dark green in color and may have patterns or variegations.
  • Its flowers are often large and showy. Often characterized by their rich colors, intricate patterns, and ruffled petals.These blooms can last for several weeks.
  • The flowers can be in shades of pink, purple, red, and white. They often have intricate patterns and markings on their petals.
  • The stems are succulent and upright, branching out as the plant matures. These stems may become woody with age.
  • Pelargonium × domesticum plants generally grow to be about 1 to 2 feet tall.
  • This plant has a bushy habit, with multiple stems arising from a central point. It tends to grow in a rounded shape.
  • Some varieties of Pelargonium × domesticum may have a pleasant fragrance,
  • Like many geraniums, Pelargonium × domesticum has a fibrous root system that spreads out shallowly in the soil.
  • Regal geraniums can be propagated through stem cuttings, which root easily in moist soil or water.
  • They are commonly grown in containers, hanging baskets, or flower beds, both indoors and outdoors.

How to grow and care for Regal geraniums (Pelargonium × domesticum)

USDA Hardiness Zones

USDA Hardiness ZoneTemperature Range (°F)Description
Zone 920°F to 30°F (-6.7°C to -1.1°C)Suitable for Pelargonium × domesticum with milder winters.
Zone 1030°F to 40°F (-1.1°C to 4.4°C)Provides favorable conditions for robust growth.
Zone 11Above 40°F (4.4°C)Ideal for continuous growth and flowering.

Planting Location

  • Geraniums prefer full sun but can tolerate partial shade, especially in hotter climates.
  • Ensure the planting location has well-drained soil to prevent waterlogging, as geraniums are susceptible to root rot.

Planting Time

  • In cooler climates, plant geraniums after the last frost date in spring.
  • In warmer climates, geraniums can be planted in fall or winter for winter and spring bloom.

Soil Preparation

  • Use well-draining soil with a pH of 6.0 to 7.5.
  • Incorporate organic matter like compost into the soil before planting to improve drainage and fertility.

Planting

  • Dig a hole slightly larger than the root ball of the geranium.
  • Place the plant in the hole and backfill with soil, gently firming it around the plant.
  • Space plants 12 to 18 inches apart, depending on the cultivar.

Watering

  • Water geraniums thoroughly after planting and keep the soil evenly moist until established.
  • Once established, allow the soil to dry out slightly between waterings. Avoid overwatering, as this can lead to root rot.

Fertilizing

  • Feed geraniums with a balanced fertilizer (10-10-10 or similar) every 4 to 6 weeks during the growing season.
  • Avoid excessive fertilization, as it can lead to leggy growth and fewer flowers.

Pruning and Deadheading

  • Pinch back young geranium plants to encourage bushy growth.
  • Deadhead spent flowers regularly to promote continuous blooming.
  • Remove yellowing or dead leaves to improve air circulation and reduce disease risk.

Overwintering (for colder climates)

  • In regions with frost, geraniums can be overwintered indoors.
  • Before the first frost, dig up geranium plants from the garden and pot them in containers.
  • Place the containers in a cool, sunny location indoors and water sparingly during the winter months.

Pest and Disease Control

  • Monitor plants regularly for pests such as aphids, spider mites, and whiteflies. Use insecticidal soap or neem oil to control infestations.
  • Keep foliage dry to prevent fungal diseases like powdery mildew and botrytis. Water at the base of the plant, avoiding overhead watering.

Propagation

  • Geraniums can be propagated from stem cuttings or by division.
  • Take stem cuttings from healthy, non-flowering shoots and root them in moist potting soil or water.
  • Divide established plants in spring or fall by carefully separating the root ball into sections with a sharp knife.

Varieties of Regal geraniums (Pelargonium × domesticum)

Angel EyesCompact variety with small flowers in shades of pink, red, or white.
CarolProduces large, double flowers in shades of pink, red, or white.
Happy FaceCompact variety with large, semi-double flowers in various colors including pink, red, and white.
Hilda M. TerryKnown for its deep pink flowers with a darker center.
Lara StarshineFeatures semi-double flowers in shades of pink, red, and white with a distinctive star pattern.
Lavender LadProduces lavender-colored flowers with a darker center.
SuperbellsCompact variety with small, bell-shaped flowers in pink, red, or white.