In Eve Palmer and Norah Pitman’s first volume of Trees of southern Africa, the following information is given: ‘Seedlings of the White Alder are rare. Birds destroy quantities of seed and wild pigs destroy the capsules. Mr Laughton, while Forest Research Officer at Knysna, found that the sowing of 25 muid sacks of seeds over a period of 25 years did not result in the germination of more than 250 seedlings. A muid sack contained 109.1 litres of seed! ’

Rachel Saunders of Silverhill Seeds supports this finding, 'the main problem is that the seed that is produced is usually about 90% empty. We often find trees with “seed” but when you examine them, you cannot find any endosperm at all.'  (R. Saunders, pers. comm.)

Anthony Hitchcock, Nursery Manager at Kirstenbosch National Botanical Garden, has contributed the following information on the growing of Platylophus trifoliatus:

‘I have not had experience of growing this species from seed. If I did I would sow in the warm summer months and smoke treat as it is a tree occurring in the fynbos. I often find non-core fynbos species from this region responding to smoke. I would recommend keeping the seed under glass to have higher humidity based on the natural habitat. I have seen seedlings growing out of moss on the embankments of streams where it is moist and humid. The seed is fine and probably has little reserves. Another intervention would be to dust the seed with a pre-emergence damping off fungicide to prevent rotting/infection.’

‘I have grown them successfully from cuttings I collected in Bain’s Kloof. I collected in mid-summer on New Year’s day when it was hot, but I kept the cuttings in cool shade next to the stream amongst the boulders and under shade of trees. They were at no time exposed to stress. I was very careful in selecting the cuttings. The tree was mature and in good condition. I looked for cuttings that showed active growth which I found near the ends of the branches. Most of the tree presented material where the tips were leafy, but the stem was short and often curved, with closely packed nodes and short internodes. I avoided these and looked behind the terminal growth for side shoots that were straight, with longer internodes and showed active and hardened-off growth, with the wood having changed from green to light brown. It was easy to detect these more vigorous, actively growing shoots and they were straight, which is necessary for better quality plants. Where possible, I selected heel cuttings, but tip cuttings also work. The cuttings were rooted in 50:50 milled bark and polystyrene which allows for good aeration. Used Seradix 2 rooting powder 2 000 ppm for semi hardwood cuttings and placed them on a heated bench 25 ºC, under mist to prevent desiccation.’

Most people do not have access to these facilities, so alternatively place in a pot just large enough for the cutting and using the same rooting material and hormone. Cover the tree cutting with a clear plastic bag and seal with an elastic band. You can use wire to support the plastic and keep it away from the leaves. Place out of the direct sun, in a warm, shaded place and regularly check that the rooting medium is not drying out and remove any dead leaves. You can also apply a broad spectrum fungicide drench to prevent infection. Cuttings are known to root well, using this method, but it takes longer. When the cutting starts to show signs of growing, you may assume that roots have begun developing. Check the cutting for roots and if well developed, begin the hardening-off process, by first making a slit in the plastic to allow for more air circulation. A week later, open the opening in the plastic bag further and then remove after about 2 weeks. Close up the plastic bag and slow the process if you notice the plant is showing signs of stress or desiccation. It is recommended that you water in Kelpac to feed the roots and reduce stress. Once the plant is hardened off, re-pot into a well-drained potting medium that does not contain manure. Conifer-growing medium is ideal and available from some retailers. Grow the young tree on in a protected place where it gets morning sun, but not full day or hot afternoon sun, or under 40% shade cloth. Feed regularly with an organic fertilizer following the instructions.

If the cutting develops callus and no roots, then wash the cutting and nick the callus with a clean blade and apply a broad spectrum fungicide. Replace in a fresh batch of rooting medium and start the process again, whether under plastic or mist. Experience has shown that callus treated this way, most often results in vigorous root development.

The collection from Bain’s Kloof rooted very well, over 80%, and the plants are vigorous. The plants from cuttings are erect and sturdy growing and have smaller leaves than the Betty’s Bay form.

Adam Harrower reports that cuttings he collected and others by James Deacon, rooted poorly. Adam took similar cuttings and also cuttings from material suckering from the base of the tree from the plant in Harold Porter, the kloof above and to the right of the Garden. James Deacon from the same area, but we cannot be sure of the quality of James’ collecting. The Betty’s Bay plants that rooted, have struggled being floppy in growth habit and had to be staked, but still flopped above the stake. The leaves were in poor condition being yellowish and tending to become brown on the edges. Adam wonders if they are not infected with broad mite, which we have identified as a major problem in this garden.

Timing: ‘I always recommend propagating trees in summer when it is warm and they are actively growing even if the tree comes from the Western Cape.’