How to propagate passion flowers from cuttings

Passion flowers are among the most exotic of all ornamental climbing plants, yet despite many species and hybrids being relatively hardy there are very few in general cultivation, particularly in the United Kingdom. However, while the range of passion flowers available from most plant retailers is generally limited, if you can find the species or hybrid that you are looking for and get permission from the owner they you can propagate your own passion flowers from cuttings. So, How do you propagate passion flowers from cuttings?

The best results are achieved by either taking softwood cuttings in the spring or semi-ripe cuttings during the summer. As a general rule passion flowers become hollow a certain distance back from the growing tip. These hollow sections are notoriously hard to root and are also prone to fungal rots so unless you are short of propagation material avoid using cuttings with hollow stems. If you have little choice other than to use material with hollow stems then consider blocking the hollow ends with lard or horticultural wax. Passiflora incarnata is a good example of this and have stems which become hollow a short distance behind after the growing tip.

Particular species can experience particular problems. For example Passiflora racemosa cuttings are relatively easy to root but will not produce any further stem growth unless the apical tip is left on the cutting.

How to propagate passion flowers from cuttings
Stem cuttings are at their most viable during the softwood stage which occurs around May. This is recognised when the growth tips break off easily when being bent. Be that as it may you can also receive good results from semi-ripe cutting in July and August. The best time to take cuttings is in the morning and if there has been little recent rain, thoroughly water the mother plant the day before. Using a sharp, sterilized blade take 3 to 5 inch cuttings, making your cut just below the leaf node of the first or second mature leaf from the end shoot. Remove the bottom half to two-third leaves and tendrils. Larger-leaved specimens may need part of the remaining leaves removed to prevent the cutting from drying out before it has a chance to produce roots. If you are not striking the cuttings immediately then place them in a polythene bag containing some damp kitchen roll. Keep the bag in cool, dark conditions until you are ready to work with the cutting material.

For the potting compost either use a sphagnum moss peat-based seed and potting mix or make your own using a 50:50 mix of horticultural sand and fine sphagnum mos peat. Using 3 inch pots, fill with the compost mix and then pre-drill one hole in the centre using a dibber. Dip the ends of the cutting rooting hormone and place it in the hole being careful not to wipe the rooting hormone off the end of the cutting. Gently compress the compost to secure the cutting in place, then lightly water.

Place the pots inside a heated propagator or propagating frame at a temperature of between 16-21 degrees Celsius. Alternatively seal the pots inside a clear polythene bag and place on a warm bright windowsill, but avoid direct sunlight. Don't let the cuttings get to wet inside their respective protection so provide adequate ventilation to allow the foliage to dry off each day.

You can expect new foliage to be produced within 3-4 weeks, but avoid tugging on the cuttings to check if rooting has occurred as this can easily damage the new root system. Instead check the drainage holes at the bottom of the pot to see if any root growth can be seen. Once the root system has established in the pot the cuttings can be potted on into 4-5 inch pots using John Innes 'No2' compost. If you are propagating plants from Tacsonia subgenus of Passiflora then use an ericaceous compost instead as they prefer alkaline to slightly acidic conditions.

Overwinter hardy species and hybrids under the protection of a cold greenhouse in their first year. Then harden off before planting outside into their final position once the threat of late frosts have passed.

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