Geraniums can flower for a very long time, but “almost continuously for over a year” only happens if you keep them in ideal growing conditions and do a few key things consistently.
Here’s what actually makes the biggest difference:
First, deadhead spent flowers regularly. As soon as a bloom starts fading or drying, pinch or cut it off right above the nearest healthy leaf node. This stops the plant from putting energy into seed production and pushes it to make new flowers instead.
Second, give them plenty of sunlight. Geraniums need at least 5–6 hours of direct sun daily. In lower light, they survive, but flowering slows down a lot.
Third, avoid overfeeding nitrogen. Use a balanced or bloom-focused fertilizer (higher phosphorus, lower nitrogen). Too much nitrogen gives you lots of leaves but very few flowers.
Fourth, water properly: let the top layer of soil dry slightly before watering again. Constantly wet soil reduces blooming and can cause root issues.
Fifth, keep them slightly “stress-balanced.” Mild root restriction (like not over-potting into huge containers) often encourages more flowering than excessive space and rich soil.
Finally, in warm climates, geraniums can keep blooming almost year-round outdoors. In colder periods, bringing them indoors near a bright window or under grow lights can extend the season significantly.
If you want, tell me whether yours are in pots or ground—I can give a more precise routine for your setup.
