7 Differences Between Geranium (Hardy Geranium, Cranesbill) and Pelargonium (Tender Geranium)

Are you a gardening enthusiast who’s ever been confused by the terms “geranium” and “pelargonium”? Well, you’re not alone!

Here at Gardeners’ Yards, I have decided to call a spade a spade, so to speak, and to address the difference between cranesbill and geranium.

While both belong to the Geraniaceae family, they are different genera with distinct characteristics and care requirements.

Just for you, I will clarify the confusion surrounding these two beautiful types of plants and explore their origins, appearance, growing habits, and ideal growing conditions.

By the end, you’ll be able to confidently identify and care for both geraniums (hardy geraniums) and pelargoniums (tender geraniums), bringing a touch of vibrant Mediterranean color or cottage garden charm to your garden.

Difference Between Cranesbill and Geranium

There is no difference between cranesbill and geranium! They are the same plant, with cranesbill being the common name for geranium, usually used in the UK and Europe.

The growers there still use the name cranesbill on plant labels alongside the correct name of geranium. Although confusing, seeing a plant labeled cranesbill is another useful way of identifying it as a hardy geranium.

Geraniums vs Pelargoniums

Primarily, geraniums are hardy perennials that will survive cold winters and frost. Pelargoniums are tender perennials that are only hardy in frost-free climates. There are also distinguishing differences in both leaves and flowers.

Read on for more details on how these two plants differ and how they can bring abundant flowering charm to your garden or yard.

Detailed Differences Between Cranesbill and Geranium

Botanical Genus

• Geranium (Cranesbill, Hardy Geranium): This genus of perennial plants is known for its resilience and ability to thrive in temperate climates. It is often referred to as hardy geraniums.
• Pelargonium (Geranium, Tender Geranium): Often mistakenly called geraniums, these plants belong to a different genus, Pelargonium, and are mostly grown as annuals or houseplants in colder climates.

Climate Tolerance

• Geranium: Cranesbill/Hardy geraniums. These plants can withstand cold temperatures in the open ground, even winter frosts.
• Pelargonium: Pelargonium. A tender perennial that is not frost-hardy must be brought indoors or treated as an annual in areas with cold winters and periods of frost.

Growth Habit

• Geranium: With a natural spreading habit, geraniums are ideal for ground cover, borders, and naturalized areas.
• Pelargonium: Some varieties are compact and bushy, ideal for containers, pots, or flower borders. Others have long stems, making them suitable for hanging baskets.

Flower Colors and Shapes

• Geranium: The flowers are more modest and come in shades of blue, pink, purple, and white. Some have white or black centers, and some have delicate darker veins.
• Pelargonium: Known for its vibrant and varied flower colors, including red, pink, white, purple, and orange. Some varieties have single-colored flowers, and some have bi-colored blooms.

Leaf Shape

• Geranium: Leaves are usually deeply lobed, delicate, and soft to the touch.
• Pelargonium: Leaves vary widely in shape and often have decorative features, such as variegation or zonal patterns. They are also scented, with some having distinct scents such as lemon, rose, peppermint, and apple, among many others.

Perennial vs. Annual

• Geranium: These are true perennials and will return year after year with proper care.
• Pelargonium: Typically grown as annuals in colder climates, although they are perennials in their native warm climates.

Usage

• Geranium: Perfect for perennial borders, ground cover, and naturalized garden settings due to their spreading nature and resilience. They are also highly attractive to pollinating insects and can play a beneficial role in increasing biodiversity in your garden.
• Pelargonium: With vibrant flowers and attractive foliage, these plants are ideal for bright, decorative displays in containers, window boxes, and seasonal bedding. They are also excellent houseplants.

Geranium (Cranesbill/Hardy Geranium)

Geranium, commonly known as hardy geranium or the UK common name of cranesbill, is a much-loved garden perennial due to its resilience, long blooming period, and attractive foliage. Here’s a detailed look at this versatile plant:

Botanical Characteristics

Geranium is a genus of low-growing plants with flowers in a range of colors, including blue, pink, purple, and white, often with delicate veining. The leaves are either heart-shaped or rounded and soft. Some varieties also have scented leaves like their pelargonium cousins. In addition, they are fully frost-hardy.

Growing Conditions

• Light: Hardy geraniums grow very well in full sun to some shade. However, in hot climates, they thrive best with some afternoon shade.
• Soil: They prefer well-draining soil that contains plenty of organic matter. This is easily achieved by adding compost to improve soil fertility and structure.
• Watering: Water regularly for the first year until the plants are established. The soil should be moist but not soggy. Overwatering could cause the roots to become waterlogged and mold to develop on the leaves. Generally, if planted in a suitable location, geraniums will look after themselves. Expect them to die back and disappear in winter, with new growth reappearing in spring.

Planting and Maintenance

• Planting: Ideally, plant in the spring or fall when the soil is warm and not too dry. Space plants apart, allowing enough room for them to grow to their mature size. This is essential for good air circulation, greatly reducing the potential risk of fungal diseases.
• Pruning: Regularly deadhead spent blooms to prevent all the plant’s energy from producing seed, which will also encourage continuous flowering. Regular pruning will help keep them tidy and free them from their natural sprawling habit.
• Fertilization: Spring is the best time to apply a balanced, slow-release fertilizer. Then, fertilize again with a liquid feed after the first flowering to encourage more blooms. In addition, if there’s a prolonged dry spell, a mulch of rotted organic material is very effective as a fertilizer and helps retain moisture.

Varieties

There may be very little difference between cranesbill and geranium; however, geranium varieties are more popular among gardening enthusiasts. Popular varieties of hardy geraniums, as recommended by the Royal Horticultural Society, include:

• Geranium ‘Rozanne’: Popular for its long flowering season from July until October. This geranium produces vibrant blue flowers with large white centers.
• Geranium Ann Folkard: This geranium has golden leaves contrasting with its bright magenta flowers and black centers. It is valued for its extended flowering season from June until September.
• Geranium ‘Mrs Kendall Clark’: This lovely soft lavender-blue geranium attracts butterflies and pollinating insects. It is particularly drought-resistant and flowers from late spring until early summer.

Benefits

• Low Maintenance: Once established, geraniums require minimal care and will soon spread out and provide excellent ground cover. With a long flowering season, they are also one of the few plants that grow well underplanted with shrubs and trees. Generally, a variety suits all areas of your garden or yard. Geranium sanguineum and Geranium pratense varieties thrive in full sun, provided the soil is moist. Otherwise, all geraniums will grow best when they receive early and afternoon sun.
• Pest and Disease Resistance: They are fairly resistant to pests, even slugs. Hurrah! However, they require reasonable air circulation to reduce the risk of fungal diseases. They will benefit from pruning after the first flush of flowers and again in autumn.
• Versatility: Provided you meet their growing needs, they are suitable for borders, ground cover, and rock gardens. They are also perfect for naturalizing in wildflower gardens.

Winter Care

When the foliage fades in autumn, cut back to tidy up the plant. This will reduce the risk of harboring pests and diseases and preserve the plant’s energy before it enters its dormant period. In exceptionally cold regions, in late fall, protect the roots from freezing temperatures by mulching around the base of the plants.

Note: In general, bare-rooted or pot-grown geraniums can be planted out anytime during the year except when the ground is hard with frost.

Pelargonium (Tender Geranium)

Pelargoniums, commonly called tender geraniums or geranium pelargoniums, are a sight to behold when in full flower. They provide summer color from June until September in colder regions or even all year round in frost-free climates. Another bonus is the scented leaves, with some varieties having scents of lemon, rose, mint, and apple, to name a few.  As part of the Geraniaceae plant family, they are cousins to the hardy geraniums.

Botanical Characteristics

Pelargoniums are characterized by thicker and often fragrant leaves that can be round with marked centers that are soft, velvety, or ivy-shaped. Another characteristic is the thicker stems that produce clusters of bright, showy flowers in red, pink, white, and orange shades. Several varieties, such as zonal, ivy-leaved, regal, and scented-leaf, offer unique habits and flower forms. They will tolerate dry conditions but not survive frost or harsh winters outdoors.

Growing Conditions

The growing conditions of cranesbill and geranium differed greatly. Here is a detailed growing condition for hardy geraniums.

• Light: Pelargoniums thrive in full sun, requiring at least 6 hours of direct sunlight daily. However, the ivy-leaved pelargonium will tolerate some midday shade.
• Soil: Nutrient-rich soil is essential, especially when growing in containers and hanging baskets. Mixing good-quality compost and perlite is also vital to ensure good drainage.
• Watering: As soon as you notice the top inch of soil is dry, your plants need watering. Dip your finger to fingertip depth into the topsoil; if it is dry to the touch, your pelargoniums will likely be thirsty. However, avoid overwatering, as pelargoniums are susceptible to stem and root rot if the soil is constantly soggy. Be mindful that sun, temperatures, and wind all contribute to drying out your plants.

Planting and Maintenance

• Planting: Plant in the spring after the last frost. Space plants to allow enough room for mature growth and good air circulation. This will avoid overcrowding and reduce the risk of disease.
• Fertilization: Feed regularly with a balanced liquid fertilizer every four to six weeks during the growing season. A flower-enhancing fertilizer high in phosphorus can promote more blooms. Note: For hanging baskets, use granular fertilizers when planting up. Then, only lightly water with a liquid feed if extra nutrients are needed during the season.
• Pruning: Regularly deadhead spent flowers and trim back leggy growth to maintain a compact shape and promote more blooms. This will also benefit air circulation.
• Diseases: There are a few diseases to be aware of, mainly caused by incorrect watering and poor air circulation. The fungal disease Botrytis Blight causes greyish-white mold that affects the stems and leaves. Isolate the plant, remove all affected parts, and treat it with a fungicide. Root rot is caused by excessive watering and can be managed by less watering and improving drainage. Look for signs of yellowing leaves. Again, treat with a fungicide. Pelargonium rust is a fungal disease that causes the leaves to turn yellow or red. Remove affected parts, isolate the plant to improve circulation, and treat with a fungicide.
• Pests: Aphids, thrips, whiteflies, and greenflies are some of the common pests you might come across. They all feed on the sap of your pelargoniums and, over time, will weaken the plant. Signs to look out for are the visible presence of the bugs, usually underneath the leaves. Again, yellow leaves with poor growth and sticky substances are signs of pest infestation. There is also the presence of ants climbing through your plants, which are attracted to the aphids. Or, more precisely, the sticky substance they leave behind.

Overwintering

As you know, pelargoniums are not frost-hardy and are usually treated as annuals. But if you want to overwinter and save them, the best ways are to repot them and bring them indoors. This could be a greenhouse or garden room where temperatures remain above freezing. Alternatively, you can treat them as houseplants that will likely continue flowering in a warm indoor environment. Taking cuttings before discarding the parent plant is another method.

• Indoors: Place on a sunny window or another sunny spot. Reduce watering and don’t fertilize during the dormant period.
• Cuttings: Take cuttings in late summer to propagate new plants indoors over winter.

Varieties

• Zonal Pelargoniums (Pelargonium x hortorum): These popular pelargoniums will grow into upright, bushy plants. They have distinct leaf markings and produce many outstanding flowers throughout the summer.
• Ivy-Leaved Pelargoniums (Pelargonium peltatum): These have long, trailing growth, which makes them perfect for hanging baskets. Their leaves are shaped like common ivy, hence the name. Again, this variety produces outstanding flowers throughout the summer.
• Regal Pelargoniums (Pelargonium x domesticum): This variety is well known for its vibrant, ruffled flowers. The leaves are either plain green or variegated green and white. Growth is bushy and compact.
• Scented-Leaf Pelargoniums (Pelargonium spp.): Valued for their fragrant foliage with various scents like lemon, rose, or mint. This variety tends to have more modest flowers that will bloom throughout the warmer months.

Benefits

• Versatility: Pelargoniums will happily grow in pots, containers, hanging baskets, or the open ground. They come in a wide range of colors and also grow well in mixed planting schemes.
• Attract Pollinators: The bright flowers are beautiful to bees and butterflies, adding biodiversity to the garden.
• Decorative Foliage: The foliage is an outstanding feature in itself. All varieties are scented, with some having signature scents, and many also have distinctive markings.

Pelargoniums are valued for their ease of care, prolonged blooming period, and wide range of colors and forms. These tender geraniums will brighten any garden or indoor space with stunning displays by providing the right growing conditions and regular maintenance.

Final Words

I am sure you have no issues with the difference between cranesbill and geranium!

While Geraniums and Pelargoniums adorn our gardens with their outstanding floral displays,  they are distinct plants with unique characteristics. Geraniums have charming flowers and rustic charm, and pelargoniums take center stage with a vibrant floral display. Now you are up-to-date with your knowledge of this plant genera, you can confidently choose the perfect geranium or pelargonium for your garden and provide it with the care it needs to thrive.

Do you have a favorite type of geranium or pelargonium? If so, we would love to hear about your gardening adventures with these beautiful plants.