Geraniums are versatile plants of both the genus Geranium and also Pelargonium. Together, the two groups include wildflowers, annuals, biennials and perennials. Soil choice should be guided by whether geraniums are planted in containers or in the ground.
Indoor Soil Needs
Many types of potting soils exist for plants grown indoors in containers. Choose one that drains well.
Outdoor Soil Needs
For geraniums that will be kept outdoors in containers, it is acceptable to use garden soil as long as it is not clayey. If your soil needs extra drainage, you can add compost or coir, made from coconut husks.
Soil in Gardens
Again, drainage is an important quality; therefore, soil amendments are a must for clay or silt soils. Soil that drains too much, such as sandy soil, can be adjusted for geraniums with the addition of organic materials.
Geraniums should be planted in the sun, increasing the need to keep them watered adequately. Let the soil dry between waterings.
Geraniums like a soil that has a slightly acidic pH. On the pH scale, 7 is neutral, and the level of acidity increases as the pH value decreases. Geraniums thrive at around 6.5.