With over 200 species of geranium (Pelargonium) available, there is one to fit nearly every color scheme and landscaping style. Geraniums grow outdoors in U.S. Department of Agriculture plant hardiness zones 10 and 11, but they are frequently grown as houseplants or annuals in other zones. Their brilliant blossoms give them their most appealing feature, and it doesn’t take too much care to help the blossoms look.
Let There Be Light
Geraniums are greedy about sunlight; they need at least six hours per day to build sufficient energy to bloom. Without sufficient lighting, your plants might continue to grow, but it is unlikely that they will bloom. You might notice the stems getting longer than ordinary with a “leggy” appearance, meaning they grow taller without always adding new leaves — they look like narrow legs reaching to the sunlight. Outdoors, move the plants into a sunnier location, perhaps one with south or west exposure. Indoors, find a window using more direct lighting to encourage blooming.
Too Cool to Blooms
Because warm-weather bloomers that don’t like too much cold or hot, geraniums prefer daytime temperatures between 70 and 85 degrees Fahrenheit. They manage nighttime temperatures of approximately 60 degrees throughout the blooming season. Many begin blooming early in the spring and continue until the day temperatures get too hot for the plants to encourage the booming cycle. If your geraniums are not blooming when you think that they should, check the temperature; it could be a colder-than-normal spring, that would delay booming until the temperature warms. If they don’t bloom as long as you think they should, it is possible the heat of summer set in sooner than anticipated. Indoor geraniums, though, can bloom all year.
View the Watering
Geraniums like moist soil, but giving them a lot of water can stop them from booming. The roots need loose dirt around them so that they can breathe. When the soil becomes waterlogged, the roots can’t take in the oxygen they need, and the plant suffers. Put your geraniums in pots with drainage holes, and do not water the plant unless the upper layer of soil feels dry. With outdoor plants, ensure the soil isn’t too dense, or add amendments like compost and mud to help the dirt drain more efficiently.
Other Blooming Issues
Geraniums have moderate offspring needs — typically adding a balanced fertilizer, like a 10-10-10, every two to four weeks is a lot to keep the blossoms going. Mix 1 tbsp of water-soluble fertilizer at a gallon of water — or follow the manufacturer’s directions, should they differ — then insert it during a standard watering time. If you have recently repotted your geranium or moved it out from indoors to outdoors, it might just need time to adjust before it blooms.