4. Deadhead spent flowers
The best way to encourage continuous blooms throughout the growing season is to regularly deadhead spent flowers. This simply means removing the dead flowers by cutting the stem above the first set of leaves. As the old flowers are removed it will trigger the plant to form new buds. Fiskars talks about the how, when and why of deadheading if you’re interested in more details.
5. Fertilize regularly
Due to their quick growing nature, geraniums should be fertilized regularly to promote vigorous, healthy growth. Add fertilizer about every 2-4 weeks at a rate of about half of what is recommended on the label and water it in well.
6. Overwinter inside
If your geraniums have spent the summer outside, and you live in a colder climate it’s possible to bring them indoors for the winter to keep them growing. Before the first frost dig up plants and cut their stems back to 6-8″ long. Then transplant into the smallest pot possible, and keep in a shaded spot for about a week. After this time lapses set the plants someplace where they can get lots of sunlight inside your house. When the weather perks back up in spring move them back outside after the chance of frost has passed.