Pelargoniums are never dormant so if you can provide warm compost by using a propagator (without the lid) or a soil-warming cable, cuttings can be taken in any month of the year. Any good seed and cutting compost will be suitable and the cutting should be well-rooted in about three weeks, depending on how warm the compost is and how good the light conditions are. Do not let the compost dry out and never cover the plants. The cuttings like being dry and will rot if they are kept in humid conditions, so keep them in a light, airy place.
1. Choose a healthy shoot and cut it away from the plant above a node (leaf joint). The cutting does not need to be very long.- about 8 cm (3 in) is the ideal length. You can take several cuttings from one plant.
2. Trim the cutting to just below a node. Break off any sideshoots where they join the main stem and remove all but a few leaves. If you can, take cuttings from non-flowering shoots. If you can’t, remove any flower buds.
3. Dip the cutting a hormone rooting powder. this helps it to develop a good fibrous root system. Generally pelargoniums will root without rooting powder, providing they are kept reasonably dry and are not overwatered.
4. Insert the cuttings into moist compost in holes about 2.5 cm (1 in) deep. Firm the compost around them. Water from below after one week and again a week later. When new leaves appear, the cuttings have rooted.
Regal and zonal pelargoniums to be grown as large specimens, which were rooted as cuttings in the autumn, will need to be potted on to larger pots. Give them plenty of room to grow and remove all dead or damaged leaves. Turn the pots regularly and shape the plants by stopping.
Seeds of pelargoniums ideally need to be raised in a constant soil temperature of 20-24°C (70-75°F). Given these conditions, germination will take only a few days. If the soil temperature is not maintained germination can be erratic, so do not give up on the seeds until several weeks have passed. Plant them about 5 mm (¼ in) deep and do not let the compost either dry out or become waterlogged. Covering is not essential, but if you put the seeds in the dark, check every day to see if any have germinated as seedlings will rapidly become spindly if they are not given good light conditions.