How to Care for Geraniums—a Beautiful Addition to Summer Gardens and Containers

Geraniums are a cheerful flower that looks beautiful in the garden. In your search, you'll discover that two popular varieties exist. While there are many variations of this flower, each with its own growth habits, colors, and aromas, they all have one thing in common: They make a low-maintenance contribution to most summer landscapes. As a bonus, they're a beacon for visiting pollinators and can easily be purchased from local plant nurseries. 

Ahead, we spoke to gardening experts who talk about all things geraniums, from successfully planting and growing them (both in garden beds and containers) to transplanting tips and identifying common diseases.

How to Plant Geraniums From Seed 

Sow geranium seeds in early to mid-February to ensure you have flowering plants for spring. "When starting geraniums from seed, patience is the most important factor as it can take 12 to 16 weeks to see a flowering plant," says Nancy Trautz-Awot, a horticulture specialist with Burpee Gardening. 

1. Fill trays or pots with seed starting mix and moisten it.
2. Sow one seed per tray and cover with about 1/8 inch of seed starting mix.
3. Water gently and cover with a plastic dome to retain moisture.
4. Place the seeds in a warm spot (70°F to 75°F) with plenty of light but out of direct sunlight.
5. Remove the cover once seeds germinate, which typically takes seven to 10 days.

How to Plant Garden-Ready Geraniums

Garden-ready plants eliminate the long wait period that comes with starting from seed. At garden centers, look for strong and healthy plants with sturdy stems, bright colors, and no discoloration or signs of pests. You can plant seedlings or mature geraniums in your garden once the threat of frost has passed.

1. Gently remove the geranium from its pot and break up any circling roots.
2. Dig a small hole about the same depth as the root system.
3. Place the geranium into the hole and backfill with soil.
4. Water the plant well.

How to Care for Geraniums

These flowers may be showy, but geranium care is easy. To get the most out of your blooms, you'll want to follow some key rules regarding sun, water, soil, and fertilizer. 

Light

Geraniums love sunshine and do best in full sun settings. Make sure to place yours in an area where they'll get at least six hours of sunlight per day. Note that some varieties, such as ivy geranium, require less light.

Water

Geraniums are prone to both under and overwatering. Keep the top 1 inch of soil moist, but do not let the soil become sopping wet, says Trautz-Awot.

Soil

Geraniums require well-draining, high-quality soil in order to thrive. If you have heavy clay soil, be sure to amend it with perlite and organic matter to encourage aeration.

Fertilizer

Once geraniums are established, fertilize with a balanced, all-purpose 20-20-20 liquid fertilizer, says Jennifer McDonald, a plant expert with Garden Girls. "This provides beneficial amounts of potassium, phosphorus, and nitrogen."

Temperature

Geraniums thrive best in daytime temperatures of 70°F to 85°F and night temperatures of 55°F to 65°F, and appreciate moderate humidity levels. When temperatures rise higher than 85°F and humidity becomes too high, geraniums may begin wilting and turn yellow. They also don't tolerate the cold very well: Once temperatures go below 50°F, geraniums may suffer cold damage.

"Although they are perennials in their native tropical habitat, they're generally grown as annuals in temperate climates because they won't survive freezing temperatures," says Suzanne DeJohn, a horticulturist and writer at KidsGardening.org.

Geraniums will grow between USDA zones 3 and 9, but zonal geraniums, also known as pelargoniums, prefer warmer temperatures and grow best in USDA Zones 9 through 12.

Types of Geraniums

There are several different types of geraniums within the pelargonium species. The most common are zonal, ivy, regal, and scented. "These delightful plants all thrive in full sun and well-drained soil," says DeJohn.

Zonal Geraniums

You can recognize zonal geraniums, or pelargoniums, by their tight, mounding habit with sturdy, upright flower stems. "Their scalloped leaves have dark arcs or stripes, and it's these zones of color that give them their common name," says DeJohn. "Flower colors range from white to dark red with bright oranges and pinks in between." This type makes a bold addition to your window boxes, container gardens, and flower beds.

Ivy Geraniums

As their name implies, these geraniums create a cascading effect with their smooth, ivy-shaped leaves and vine-like growth habit. They produce the same types of elegant blooms and colors you will find in zonal geraniums. "They are a favorite for hanging baskets, tall planters, or along stone walls where the stems can drape over the sides," says DeJohn.

Regal Geraniums

Named after their bold, sometimes bi-colored blooms, regal iterations are known for producing large flowers. "Leaves have coarsely serrated edges and are often faintly fragrant," DeJohn says. "Because of their showy nature, they make excellent specimens in container gardens. Their eye-catching and slightly aromatic foliage can also make them a great indoor plant; be sure they get plenty of sunlight."

Scented Geraniums

If you're looking for blooms with a striking aroma, you'll want to check out these scented plants. "While the foliage of most geraniums is distinctly aromatic, scented geraniums take this a step further," DeJohn says. "The velvety leaves have various fragrances resembling other plants, including rose, citrus, peppermint, and pineapple."

Growing Geraniums in Containers

Geraniums look beautiful in the ground, but you can also enjoy this cheerful flower in pots placed either indoors or outdoors. "When planting in a container, ensure your container has drainage holes and opt for a well-draining potting soil to avoid root rot," says Trautz-Awot. The pot should provide enough space for the roots to grow and develop. For placement, make sure the location provides four to six hours of sunlight per day; keep the soil moist but not wet. 

Geraniums grown in containers tend to thrive when they are slightly pot-bound, so you don't need to worry too much about repotting them into a larger pot. If necessary, choose a container that's only 1 to 2 inches larger and repot the plant using fresh potting soil.

How to Prune Geraniums

Pruning geraniums encourages more prolific growth and healthier blooms. To prune geraniums, cut back long stems in late summer by removing 1/2 to 3/4 of the stem length. Cut just above a node on the stem.

How to Deadhead Geraniums

Deadheading your geraniums on a weekly basis will help keep their flowers blooming. "Deadheading is simple," says Trautz-Awot. "You just pinch off any flowers that look weak or have turned brown. Usually, a gentle tug using your thumb and forefinger will easily remove the dead flower stalk.” Doing so regularly will encourage new growth and, most importantly, help prevent diseases. 

How to Overwinter Geraniums

To preserve annual garden geraniums over the winter, dig them up in the fall and overwinter them in the house. "Keep the plant in a sunny window and keep the soil just barely moist. It can be planted back outside in the spring," Trautz-Awot says.

Common Problems With Geraniums

Geraniums are generally strong and healthy, but just like any other plant, they are prone to certain issues that can affect their appearance and quality. 

Pests

Geraniums' flowers produce sugary sap, which can make them a treat for garden visitors like deer and rabbits or less attractive pests, like aphids, says Teri Valenzuela, natural science manager at Sunday. "Proper caging of plants or an occasional treatment of neem oil can deter these uninvited guests," she says. Introducing ladybugs to your garden will help control pests, as well.

Overwatering

Geraniums need water, but too much can weaken them. Signs of overwatered geraniums include yellow leaves, especially toward the bottom, and/or pale water spots. They may also develop root rot and blackleg (a type of fungal infection) when overwatered. "Purchasing high-quality potting mix and a good pot with proper drainage can also reduce overwatering issues that can cause fungus to appear in peak heat of the growing season months," says Valenzuela.

Underwatering

While geraniums don't like too much water, too little can also create issues, says McDonald. "A simple finger test in the soil will determine whether the soil is too wet or too dry," McDonald says. "Place your index finger a few inches into the soil. It should be slightly damp but not wet."

If under-watered, your geranium leaves may develop yellow tips or fall off entirely (this can happen to the flower heads, too). Wilting and stunted growth are also signs that your plant isn't receiving enough hydration.