How to Care for Geraniums Outdoors
A tender perennial, geraniums grow year-round in warm climates but they die off and are grown as outdoor annuals in areas that experience winter freezing. Prolonged temperatures over 85 degrees Fahrenheit in summer also inhibit the plant’s growth, so in hot areas with mild winters they are often grown as a winter flower outside. Proper care in the flower garden ensures the plants remain green and blooming for the longest period possible. In colder climates, plant the geraniums outside in spring after all frost danger has passed.
- Moderately Easy
Things You’ll Need
- Spread 3 inches of compost over a well-drained, full-sun garden bed. Apply 2 lb. of a 6-6-6 analysis fertilizer to every 100 square feet of bed, then turn the compost and fertilizer into the top 8 inches of soil.
- Dig the planting holes to the same depth as the nursery containers. Set the plants in the holes so that the crown, where the stems emerge from the roots, sits level with the soil surface. Space geraniums 12 to 15 inches apart in all directions.
- Spread 2 inches of mulch, such as bark chips, over the geranium bed. Mulch prevents weeds while also retaining moisture in the soil.
- Water geraniums when the top 1 inch of soil begins to feel dry, approximately once weekly. Apply enough water to moisten the top 6 to 8 inches of soil.
- Fertilize once monthly with a soluble fertilizer when the plants are actively growing. Apply 2 lb. of 6-6-6 analysis fertilizer or 1 lb. of 10-20-20 fertilizer at each application.
- Remove the spent flowers as soon as they begin to wilt. Flower removal prevents seed formation, which helps extend the blooming period of the plants.
Tips & Warnings
In cold areas, dig up the geraniums and pot them before the first frost. Care for them indoors in a sunny window, then replant them in spring.
Grow geraniums as a perennial in hot climates by planting them in an area that receives afternoon shade in summer, such as near deciduous trees.