Pelargonium (Geranium): Plant Care and Growing Guide

What is Special about Pelargonium?

Pelargoniums are a special plant for a number of reasons. Here are a few:

Variety: With over species and thousands of cultivars, pelargoniums offer a huge variety of sizes, shapes, colors, and fragrances to choose from, making them a popular choice for gardeners.

Easy to Grow: Pelargoniums are easy to grow and care for, making them a great choice for beginners or anyone looking for a low-maintenance plant.

Long Bloom Time: Pelargoniums have a long blooming period, with some varieties producing flowers from spring through fall.

Fragrance: Many pelargoniums have fragrant foliage, adding an extra sensory dimension to their appeal.

Pest-Repellent: Some pelargoniums are known for their ability to repel insects, such as mosquitoes, and are often grown near outdoor living spaces to help deter pests.

Medicinal Properties: Pelargoniums have been used for medicinal purposes and are rich in essential oils that are valued for their antiseptic and anti-inflammatory properties.

Pelargonium versus Geranium: What is the Difference?

Pelargoniums and true geraniums (genus Geranium) are often confused, but they are different plants.

Pelargoniums are a genus of flowering plants that belong to the family Geraniaceae. They are often called “geraniums,”, particularly in North America, but true geraniums are a separate genus of plants that have smaller, less showy flowers than pelargoniums and typically have a more sprawling growth habit.

Climate: Pelargoniums are native to warm temperate and tropical regions of the world.  True geraniums are native to temperate regions of the world.

Flowers: Pelargoniums have larger, more showy flowers that are often bicolored, while true geraniums have smaller, simpler flowers that are usually a solid color.

Foliage: Pelargoniums often have fragrant, fuzzy leaves that can vary in shape, while true geraniums have smaller, more delicate leaves that are usually not fragrant.

Landscaping: Pelargoniums are often used in container gardens and as bedding plants. True geraniums are often used as groundcovers or in rock gardens.

Which Geranium for my Garden or Balcony?

Zonal Geranium: These pelargoniums have round zones or patterns in the center of the leaves and come in a variety of colors. They are mostly bush-type plants and are commonly used in borders or containers and as indoor plants.

Ivy-Leaved Geranium: These pelargoniums have trailing stems and ivy-like leaves. They are ideal for growing in hanging baskets, window boxes, or as trailing plants in garden beds. They are also suitable for training as a climber on trellises or walls.

Regal Geranium: These are large bush-type floriferous evergreen plants grown primarily for the beauty of their flowers. The flowers are large, typically double or semi-double, and have ruffled petals, giving them a frilly, almost rose-like appearance. They are often grown as houseplants or used as bedding plants in formal gardens.

Scented-Leaved Geranium: These are shrubby evergreen perennials often grown for their fragrance. When bruised or touched, the leaves emit a variety of scents, including rose, lemon, and mint. Scented geranium is used in potpourri or to flavor desserts.

Angel Geranium: They are mostly upright bush-type plants with small serrated leaves and smaller flowers. They also make a great addition to container gardens or as a border plant in garden beds.

When to Plant Geranium

• The best time to plant pelargoniums is in the spring after the last frost has passed and the soil has started to warm up.
• If you live in a region with mild winters and want to grow pelargoniums as perennials, you can plant them in the fall to give them time to establish before the winter months. However, be sure to provide them with protection from frost and cold temperatures during the winter.
• Pelargoniums can also be grown indoors year-round, so you can plant them at any time if you plan to keep them indoors. When planting pelargoniums, choose a location with well-drained soil and plenty of sunlight, and be sure to water them regularly to keep the soil slightly moist.

Where to Plant Geranium Flowers

• Sunlight: Pelargonium loves sunlight and needs at least 6 hours of direct sunlight each day. Therefore, choose a spot that gets full sun for most of the day. In regions with hot summers, pelargoniums may benefit from some shade during the hottest parts of the day. Regal cultivars prefer partial shade, and Zonal cultivars will tolerate some shade.
• Soil: Pelargonium prefers fertile, well-drained soil that is slightly alkaline to neutral. Avoid planting them in areas with heavy, waterlogged soil.
• Hardiness: Pelargoniums are typically hardy in USDA Zones 10-11. However, some species and cultivars may be more cold-tolerant and can be grown in Zones 9 or even 8 with proper protection during cold spells.
• Temperature: Pelargoniums prefer warm temperatures and cannot tolerate frost or freezing temperatures. In general, they prefer daytime temperatures between 70-85°F (21-29°C) and nighttime temperatures between 55-65°F (13-18°C). If the temperature drops below 50°F (10°C), pelargoniums may suffer from cold damage, which can cause leaf yellowing, wilting, and stunted growth. However, some species and cultivars may be more cold-tolerant than others, and some can survive short periods of cold temperatures with proper protection.
• Location: Pelargoniums can be planted in garden beds, containers, hanging baskets, or window boxes. They look great as border plants or as accents in a mixed garden.
• Watering: Pelargoniums prefer to be kept slightly dry, so avoid overwatering them.

How to Plant Geranium

• Prepare the soil: Pelargoniums prefer slightly alkaline to neutral soil. Amend the soil with compost or well-rotted manure to improve drainage and fertility.
• Dig a hole: Dig a hole that is slightly wider than the root ball of the pelargonium plant and deep enough to accommodate the roots.
• Plant the pelargonium: Remove the pelargonium from its container and gently loosen the roots. Place the plant in the hole and backfill it with soil, pressing down firmly to eliminate air pockets.
• Water the plant: Water the plant thoroughly after planting to settle the soil around the roots. Water regularly to keep the soil slightly moist but not waterlogged.
• Mulch the soil: Mulch around the base of the plant with a layer of organic mulch, such as shredded leaves or bark chips. This will help to retain moisture in the soil and suppress weeds.

Geranium Care

• Watering: Pelargoniums prefer to be kept slightly dry, so avoid overwatering them. Allow the soil to dry out between waterings, but do not let it become completely dry. Water deeply and less frequently rather than shallow and frequently.
• Fertilizing: Pelargoniums benefit from regular fertilization with a balanced fertilizer. Apply a slow-release fertilizer in the spring and midsummer or a liquid fertilizer every 2-3 weeks during the growing season.
• Deadheading: Removing the spent flowers is essential to ensure more flowers come through. Cut the stem just above the first set of leaves below the flower.
• Pruning: Pinch back the tips of the stems when the plant is young to promote bushiness and avoid legginess.
• Winter Care: If you live in a region with cold winters, you can overwinter your pelargoniums indoors or in a protected location outdoors. Prune the plants back by one-third, reduce watering, and bring them indoors.

Overwintering Geraniums

Overwintering geraniums can be a great way to save money and keep your favorite plants for another growing season. Here are some tips on how to overwinter geraniums:

• Prepare for Overwintering: Before the first frost of the season, dig up your geraniums from the garden and remove any dead or diseased leaves and stems. Cut the stems back to about 6 to 8 inches (15-20 cm).
• Store the Plant: Transplant your geranium to a small pot using regular potting soil. Store in a cool, dry, and dark location for a week, such as a basement or a garage. Then place your plant in a cool, sunny spot.
• Light: Geraniums are light-loving plants, so place your plant in a sunny spot.
• Watering: During the winter, geraniums need very little water. Water them sparingly, once a month, or when the leaves show signs of drooping. Water just enough to keep the soil from completely drying out.
• Fertilizer: Your geranium needs to rest – no fertilization.
• Temperature: Geraniums prefer cooler temperatures during the winter months, with ideal nighttime temperatures ranging from 50-60°F (10-16°C). However, they can tolerate temperatures as low as 32°F (0°C) and as high as 80°F (27°C) as long as they are kept relatively dry.
• Replanting: Once the risk of frost has passed and the weather starts to warm up in the spring, you can replant your pelargoniums in pots or in the garden. Give them a good watering and some fertilizer to help them get started.

How to Propagate

Pelargoniums can be easily propagated from stem cuttings; here are the general steps:

• Select a healthy stem: Choose a healthy stem from the pelargonium plant that is at least 4-6 inches long (10-15 cm) and has several nodes (where leaves emerge).
• Cut the stem: Use a sharp, clean pair of scissors or pruning shears to cut the stem just below a node. Remove any leaves from the bottom half of the stem.
• Prepare the cutting: Dip the cut end of the stem into rooting hormone powder, which will help the cutting to develop roots. Shake off any excess powder.
• Plant the cutting: Fill a small pot or container with a well-draining potting mix, and make a hole in the center with a pencil. Insert the cutting into the hole and gently press the soil around the stem to hold it in place.
• Water the cutting: Water the cutting well after planting, and then water sparingly to keep the soil slightly moist but not waterlogged. Place the pot in a warm, bright location with indirect sunlight.
• Wait for the roots to develop: It can take several weeks for the cutting to develop roots. You can check for root growth by gently tugging on the stem; if you feel resistance, roots have likely formed.
• Transplant the cutting: Once the cutting has developed roots, you can transplant it into a larger pot or into the garden.

Pests and Diseases

Geraniums can be susceptible to a variety of pests and diseases. Here are some common pests and diseases that can affect them and how to prevent or treat them:

Aphids: These small, soft-bodied insects can cluster on the undersides of leaves and cause leaf curling, yellowing, and stunted growth. You can treat aphids by washing them off with a strong jet of water or applying insecticidal soap or oil.

Mealybugs: They are small, soft-bodied insects that can infest pelargoniums (geraniums) and cause damage by sucking the sap from the leaves and stems. Apply insecticidal soap and ensure good air circulation.

Spider mites: These tiny pests can cause webbing on the plant, yellowing leaves, and stunted growth. You can control spider mites by misting the plants regularly, applying a miticide, or introducing predatory mites.

Thrips: They are tiny, slender insects that can cause damage to geraniums by piercing the leaves and sucking out the sap. Thrips infestations can cause distorted, discolored, or spotted leaves, stunted growth, and reduced flower production. Apply insecticidal soap and ensure good air circulation.

Whiteflies: These small, winged insects can cause leaf yellowing, curling, and stunted growth. You can treat whiteflies by washing them off with a strong jet of water, applying insecticidal soap or oil, or introducing predatory insects.

Botrytis blight: This fungal disease can cause gray or brown fuzzy mold on the leaves, flowers, and stems and can lead to stem rot and plant death. You can prevent botrytis blight by ensuring good air circulation, avoiding overhead watering, and applying a fungicide.

By monitoring your plants regularly for signs of pests or diseases and taking action to prevent or treat them promptly, you can help to ensure that your pelargoniums remain healthy and beautiful all season long.

Companion Plants for Geraniums

Geraniums can be beautifully complemented by a variety of companion plants that can enhance their growth, color, and fragrance, such as Alyssum, Calibrachoa, Dusty Miller, Helichrysum, Lavender, Lobelia, Petunia, Pennisetum, and Salvia.

Geranium repels leafhoppers and Japanese beetles. It is an excellent companion plant for Beet, Corn, Dahlia, Grape Vine, and Roses.

Click here to compare all Geranium varieties

Frequently Asked Questions

Do geraniums prefer sun or shade?

Geraniums prefer full sun to partial shade, meaning they require at least 4-6 hours of direct sunlight each day. They will grow best and produce the most flowers in a location with full sun exposure. However, in hot climates or during the hottest part of the summer, pelargoniums may benefit from some shade in the afternoon to protect them from excessive heat and sunlight.

Do geraniums come back every year?

Geraniums are typically grown as annuals in most parts of the world. However, some pelargonium species are perennial and can come back year after year in the right growing conditions. In areas with mild winters, such as USDA hardiness zones 9-11, pelargoniums can be grown as perennials and will come back year after year.

What does geranium smell like?

Geraniums can have a wide variety of scents depending on the species and cultivar. Some popular scents include rose, lemon, mint, cinnamon, and citrus.

How long do geraniums last?

Geraniums can last for several months to a few years, depending on the species, growing conditions, and care provided. In general, Geraniums grown as annuals will typically last for one growing season, which can be several months long. They will flower profusely during this time and can be propagated from cuttings to create new plants for the following season. Pelargoniums grown as perennials can last for several years, especially in areas with mild winters where they can be overwintered outdoors.