Geraniums are popular summer-blooming bedding, hanging baskets, and container plants that provide a bright pop of color and a sweet scent in your yard. However, you must get the planting timing right to make the most of these tender annuals. 

If you’re wondering when to plant geraniums, spring is usually the best time. Read on to learn why.

When to Plant Geraniums

According to Manjot Sidhu, Assistant Professor of Horticulture and Ornamental Horticulture Specialist at the University of Maine Cooperative Extension, the best time to plant geraniums is in the spring after the last frost. It’s helpful to wait until the soil reaches 60°F. 

Timings vary depending on your region, but that’s typically in late May. It may be possible to plant in milder regions as early as March. Sidhu recommends checking the USDA Plant Hardiness Zone Map to find your local last frost dates.

“Geraniums can be started indoors, but are slow to grow, so start 12-14 weeks before the average last frost date,” Sidhu says.

While most geraniums are grown as annuals (those in the Pelargonium genus), Sidhu explains that you can plant perennial hardy geraniums (from the Geranium genus) in the fall in regions with mild winters and after the summer heat has passed. 

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How to Plant Geraniums

When planting geraniums in the spring, Sidhu recommends selecting a full sun position, although she says they may still do well in partial shade. 

Annual geraniums are adaptable to various natural soil types. However, it’s best if it’s loose and well-draining—and amending the soil with organic matter can give your plants a beneficial boost. Alternatively, or additionally, “[applying] a general liquid feed or controlled-release fertilizer will improve plant growth,” Sidhu says. 

She also explains that many hybrid geraniums may not flower well at a pH below 5.5. If you have any concerns, it could be worth doing a soil test to check levels before planting and amending with lime if necessary.

Regular watering is vital for healthy plant growth, and Sidhu emphasizes the importance of applying adequate amounts so that water drains or drips through the medium at each watering.

“This also helps to avoid buildup of fertilizer salts in the medium because all geraniums are intolerant of high soluble salts,” she says.

Just drain away any standing water to prevent soggy soils and the risk of root rot.

If you’re growing geraniums from seed, sow them in rows 2 to 3 inches apart at a depth of around 1/8 inch. Space mature plants at least 16 inches apart to allow adequate air circulation. 

How to Grow Geraniums in Containers

Geraniums are popular container and hanging basket additions. The key to growing geraniums in containers is to water more regularly. This is necessary because the limited soil gets warmer faster in pots, and water evaporates more quickly.

Sidhu recommends potting in a soilless mix.

“These offer more flexibility and give a greater margin of error in controlling both the physical and chemical properties of the medium, such as porosity—as it influences gas exchange and water availability.”