You can take geranium cuttings in spring or summer as long as you remove the flower heads from any cuttings that you take. If you wait till the end of year, before the frosts come, when the plants have finished flowering you can take as many cuttings as you can without worrying about damaging the original plant.
New growth makes best cuttings, as that is where the plant’s stem cells are. Stem cells are unspecialised cells that are able to differentiate into any other kind of cell (including root cells), so this means that a new shoot is most likely to be able to grow and develop into a separate new plant.
The cutting should ideally between 5 and 15 cm long. Keep the new leaves at the tip of the cutting, but snap off any flowers or old leaves, so that the cutting can focus on developing roots.
Place the cuttings in a small vase or glass of water (indoors), and leave until roots begin to grow. Be prepared to wait up to a couple of weeks! If the cuttings do take a while, keep an eye on the water, and change or add more if needed. Occasionally cuttings do fail, but wait some time before throwing an unresponsive cutting away, as it may still take root. Some people choose to add rooting powder, but this isn’t necessary. Alternatively, if you don’t want to wait, you can plant the cutting straight into a small pot, but leaving them in water for a while lets you know which cuttings have taken.
Potting and planting out
Once your cuttings have taken root, plant individually into small pots of compost, and water regularly. Snap off flower stems that the plant tries to grow until it is more established, as flowering will waste energy. If it is still too cold outside when the cuttings outgrow their pot, then re-pot them. Otherwise, you can plant them outside as soon as the last frosts go in mid-to-late Spring.
Geraniums looks nice in pots – outdoors or indoors – but could also be used in borders. However, some varieties can grow to almost two feet high, so leave the appropriate gap between the plants. Water regularly and feed (tomato food works fine) for best results, perhaps once a week or so, but especially when in flower. If you deadhead regularly, they should keep flowering throughout the Summer.
Geraniums are not frost hardy, so it’s worth taking next year’s cuttings before the bad frosts come. Plants close to the house will be more sheltered, but we find the only way to ensure survival is to bring the plants inside if possible. This way, you can enjoy their stunning flowers for 2 or 3 years.