How To Keep Geraniums Blooming Vigorously

Cutting-grown geranium
Cutting-grown geranium

Geraniums are a must-have for many of us in our outdoor containers, planters and window boxes. They’re a favorite because they bloom from the moment of planting until the season’s end. But how can we maximize the number of blooms, keeping them producing loads of large flowers?

Here are several key points for helping geraniums flower abundantly all summer:

  • Geraniums are heavy feeders. Weekly applications of water-soluble fertilizer like Miracle Gro are vital. If geraniums run out of food, they pause flower bud formation, resulting in a period of non-bloom until energy is replenished. Regular fertilizing keeps the system in full, non-pause flower production. Even if you’ve used Osmocote slow-release fertilizer, or potting soil that contains slow-release, it’s still important to fertilize with water-soluble for top performance.
  • Although geraniums can grow in full sun, they don’t like heat. Protection from the full brunt of hot, afternoon sun is recommended. Too much shade results in weak flowering. A preferred location receives morning sun and afternoon shade.
  • Geraniums grown from cuttings bloom more prolifically than the cheaper seed-grown types.
  • Remove yellowed and dried leaves that form at the plant’s base and around soil level. The dead leaves can be a source of disease such as botrytis, also called gray mold.
  • Geraniums are often planted in combination with other spreading annuals, which frequently try to overpower the geraniums. Prune other surrounding vigorous types as needed to allow the geraniums space and light to perform their best.
  • “Deadhead” spent geranium blossoms as they whither to prevent energy from being diverted and wasted on seed production at the expense of future flowering. Instead of cutting the dead flower off directly below the withered petals, grasp the entire flower stalk and snap it off at the natural break-away point where the flower stalk meets stem. It will snap away cleanly, leaving less chance for diseases to enter.  

Happy Gardening!