If the sight of a bright red geranium in a pot on the porch gives you a nostalgic feeling, you’re not alone. Native to South Africa, this hardy annual flowering plant has been cultivated in gardens around the world since the late 1700s, so there’s a good chance you have a relative or two who grew them .
Why has this plant remained so popular for so long? Geranium care is relatively hassle-free. This means that geraniums don’t require a lot of water, food or gardening skills to look good. There are many geranium varieties, so it’s easy to find one to suit any garden, whether in a window box or along the edge of a large bed. Here are some tried and true geranium care tips that will help you grow this beautiful flower.
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Growing geraniums at a glance
Common name: Geranium, garden geranium
Scientific name: Pelargonium
Hardiness zone: 10 to 12, annually in colder zones
Land: Fertile, well-draining soil; pH 6 to 7.5
Light: Full sun, partial shade in warm climates
Water: Moderate to ordinary water
Food: Little or no feeding in rich soil; 3 or 4 feedings during the active growing season in poor soil
Propagation: Sow seeds indoors or propagate from stem cuttings.
Security: Mild toxicity to pets in some varieties
Properties of Geranium
Garden geraniums are popular for a reason; Geranium flowers boast spectacular colors and most varieties produce showy, long-lasting blooms. However, the plants themselves are low maintenance. Common geraniums, aka Pelargonium, can grow up to 2 feet tall and wide. Their leaves range from soft velvet black to chartreuse, and their flowers can be white, red, pink, orange, and deep purple.
In general, most gardeners think Pelargonium when talking about geraniums, but it is not technically correct. True geranium, also known as cranesbill, is a perennial geranium that usually grows low to the ground. But referring to geraniums as geraniums has been common practice since the late 18th century, so no one will blame you for calling them by their popular name.
There are several types of geraniums of note. Garden geraniums or common geraniums (Pelargonium x gardens), are the classic flowers that your grandparents grew in their flower beds or containers. P. zonal are zone geraniums, a P. x gardens variety that can survive slightly cooler temperatures. There are also scented geraniums (P. spp.), which are prized for their fragrant leaves with aromas similar to lime, lemon, rose and even nutmeg.
ivy geranium, P. peltatumhas ivy-shaped leaves that trail over pots and beds, and its flowers tend to be less showy than those on P.x of the gardens Lady Washington or Martha Washington pelargoniums have less rounded geranium leaves than their cousins, but their flowers are often bi-colored.
Recommended Geranium varieties
- Italy’s Sky (P. x gardens variegated ‘Skies of Italy’): Variegated white and green leaves with bright red flowers.
- Indian Dunes (P. x gardens ‘Indian Dunes’): A chartreuse leaf with a bronze center with red-orange flowers.
- Daredevil Claret (P. zonal ‘Daredevil Claret’): A large flower with bright red flowers, these red geraniums are slightly more cold tolerant than other types.
- Daredevil Snow (P. zonal ‘Daredevil Snow’): Another hardy geranium with a profusion of beautiful snow-white flowers, geraniums look stunning in a monochromatic garden or moon garden.
- Black Velvet Rose (P. x gardens ‘Black Velvet Rose’): A dark-leaved geranium with a striking contrast of soft-pink flowers.
- Mosquito Shoo scented geranium (P. curled): A citronella-scented geranium said to repel mosquitoes in the immediate area.
- Nutmeg-scented geranium (P. x fragrant ‘nutmeg’): A nutmeg-scented geranium with small white flowers.
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Common geraniums can be grown as perennials in USDA zones 10 to 12, and some varieties are also hardy in zone 9. In colder regions, they are grown as hardy annuals, usually in containers brought indoors for overwintering geraniums. True geranium species are often more cold hardy, but this varies by hardiness zone.
Grow geraniums in full sun. In warm climates, partial sun is fine. A common bedding plant, they should be grown in fertile, fast-draining soil. If the soil is rich, geraniums need little fertilizer during the growing season; they need more in sandy or nutrient-poor soil. But all geraniums love containers.
When is the best time to plant geraniums?
Plant geraniums directly in your garden after all danger of frost has passed. This can be anywhere from February in mild climates to May in northern climates. In zones 10 to 12 (and zone 9 for some types), geraniums can be kept outside year-round, but you should only plant new geraniums in the warmer months.
Where can geraniums grow?
Geraniums can grow in full sun. In climates with very hot summers, partial sun is fine. Geraniums prefer to be a little rooted, making them suitable for containers, window boxes and narrow garden beds as well as raised beds and borders. Plant bright red geraniums in front of blue hydrangea flowers for an easy, show-stopping flower bed.
How do you plant geraniums?
Before planting your geranium, water it thoroughly for a few hours before removing it from its nursery. Then let the soil dry a little.
When planting in the ground:
- Dig a hole a few centimeters deeper and a little wider than the geranium’s pot.
- Remove the plant from its grower’s pot (typically a 4- or 6-inch plastic pot).
- Fill the hole with a potting mix and place the geranium so that its crown is level with the soil.
- Add planting mix to the sides and surface of the plant.
- Water thoroughly, but do not flood.
If you are planting in a container:
- Choose a container that allows for a few centimeters of growth both in width and depth.
- Fill the pot with potting soil so that there is room for the geranium.
- Remove the plant from its grower’s pot (typically a 4- or 6-inch plastic pot).
- Add the geranium to the container, making sure to fill in enough dirt underneath to make the geranium’s crown level with the container’s soil (typically allow 2 to 3 inches of space from the lip of the pot).
- Water, but do not flood.
Do geraniums grow well in containers?
Geraniums thrive in containers, so geranium care is just as easy when they are in pots. Also, planting geraniums in pots allows you to bring geraniums indoors to overwinter. Generally, geraniums don’t mind being a little root bound, so they don’t require a ton of growing space to still look their best. The best pots for geraniums are only about a size larger than the nursery pots they come in. With so many geranium colors, container-grown plants can complement indoor, patio or deck decor, and outdoor landscapes.
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One of the most common mistakes gardeners make with geraniums is overwatering. Geraniums can cope with dry conditions better than many other annuals, and they absolutely cannot tolerate being soaked.
Only water a geranium in the soil if it has been consistently dry and warm. In containers, allow the soil to dry out completely between waterings. For this reason, it is also a good idea to plant geraniums together with other sun-loving container plants and drought-tolerant plants, such as perennial grasses, sun hat and succulents.
Geraniums are big bloomers but not heavy feeders. If planted in well-draining, richly composted garden soil at the beginning of the season, they may not need fertilization at all. If planted in containers or poor soil, fertilize geraniums once a month during peak season (May to September). The best fertilizer for geraniums is a balanced mixture, such as 10-10-10 or 15-15-15.
Geraniums are some of the least maintenance plants in the garden, as their flowers last a long time. However, to encourage new blooms, remove flowers as soon as they fade or if they look damaged after a heavy rain. The plants do not need heavy pruning, and you can remove dead or yellowed leaves by hand.
Taller geranium varieties, such as Martha Washington, may require some pruning to keep a rounder, neater shape. Geraniums kept indoors will become bushy if the stems are cut back to about 4 to 6 inches long in early spring before being taken outdoors again.
Propagation of geraniums
Geraniums can be propagated both from seed and cuttings, but most growers buy them in 4-inch or larger growing pots ready to go into a container or garden.
Learning how to propagate geraniums requires a bit of a learning curve because they require a consistent temperature to germinate. Geraniums can be propagated from seed by sowing seeds indoors in winter (January or February) and keeping the seeds at a constant temperature of 70 to 75 degrees Fahrenheit. They can then be planted outside after your last frost date has passed.
Some gardeners are successful in propagating geraniums from cuttings towards the end of the hottest months (July and August) and keeping them indoors until the following spring.
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Geraniums contain the chemicals geraniol and linalool in their leaves and flowers. These chemicals are toxic to dogs, cats and horses if ingested. Fragrant geraniums have more of these compounds in their leaves, making them mildly more toxic than regular varieties.
Potential pests and diseases
Geraniums generally tend to be hardy plants. The most common geranium pests include aphids, spider mites and whiteflies, all of which can be treated with a mild insecticidal soap. Often these pests are attracted to stressed, waterlogged plants. If your flowers look tattered, this could be a sign of geranium budworms, also known as tobacco budworms. Bacillus thuringiensis (Bt) can sometimes be effective against the bollworm without harming other pollinators.
Preparing geraniums for winter
If you live in USDA Zones 9 through 12, your primary overwintering tasks for most of your geraniums will be to cut flowers and handpick brown or yellow leaves. If your geraniums are leggy due to lack of sunlight, you can trim them back, but do not prune heavily.
In areas where there is frost, geraniums should be brought indoors in winter or treated as annuals and pulled out and replaced with cold-tolerant seasonal annuals such as pansies or mums. Gently introduce overwintered geraniums to sun and wind by first placing them outdoors in a shaded and sheltered area, then eventually increase sun exposure by gradually moving the container.
Looking for more flowering plants? See our guides for growing dahliashibiscusand milk food.