Collecting Geranium Seeds
When the rostrum dries completely, the seeds come out, and each of them is attached to a mericarp. You should collect them when they are ripe enough, but they should not eject from the rostrum. When the rostrum becomes slightly dark, and they start lifting from the mericarps, it's an indication that they are ripe enough.
How to Grow Geraniums From Seeds?
It is not that tough, but you need to be patient as they take time to mature. You need to sow the seeds around mid February, and after about two weeks, flowering starts. You can also plant a series like Multibloom, Maverick, Orbit, and Elite, as their features are similar, but the flower colors are different.
For planting them, you need to fill a container with soil, about an inch from the top, and firm it up. Water the container and sow the seeds, ensuring that each of them is about 3 inches from each other. Once you have sown them, water them by either submerging the container in water and then letting the water to drain, or you can also use a soft spray.
While planting them, make sure to provide the plant with full sunshine during spring, winter, and fall; however, in the summer, half a day of sunshine would be enough. While watering, ensure that you water the plant thoroughly and make the soil wet. If the temperature outside falls below 32º F, you should place the plant inside your house, or it may die.
Thus, you can opt to grow them in your backyard, or collect some from the wild. From wherever you collect them, make sure that you take good care of them.