The Phyto-Philes: Pterodiscus ngamicus, Part 2
Created | Updated Nov 9, 2014
Pterodiscus ngamicus
Part 2 of the story.
Growing Pterodiscus Ngamicus
This species must be considered a 'specialty', for their charming flowers and interesting thick stems. I would recommend that you first establish your success with growing 'run of the mill' succulents like cacti, aloes or mesembs. You need experience with soil and watering regimens. Like other succulents, this species needs to be grown in well-draining soil, and is sensitive to overwatering. But it also tends to wilt quickly if not given enough water. You might find that even the best of care still leads to some of your specimens getting fungal infections, the bases of their stems rotting. The danger sign is if, in the middle of the growing season, your plant wilts and does not respond by perking up again a day or two after watering. If you catch such a case quickly, you can save a plant by removing it from the soil and cutting away the rotted sections (also cut off the wilted leaves and shoots). Then you must let the wound heal over. This is done by keeping the plant in a warm, dry, shady place for a week or few. Just put it on some paper or a piece of cloth and let it lie there. When the wound is covered in thick scab tissue, you can re-plant it. This time, use clean and better-draining soil to minimize the chance of it rotting again. Also you must make sure it is planted shallow. The more of the bottom of the stem that is in the dirt, the greater the risk of rotting. It only needs to be a centimetre/half an inch into the soil. It will form roots in a few weeks and if all goes well, your specimen will be saved and soon make new leaves and flowers.
Also, at the end of the growing season, the leaves and thin shoots will die no matter what you do. But this is normal, it means your plant is going into dormancy. To keep your specimen neat, trim off this dead growth. From this point on, do not give it any water at all until the next season. Watering the plant while it's dormant practically guarantees that it will rot. The same for starting to water it too early during the growing season. It is best to wait until the fresh, green points of the new shoots and leaves actually appear on the stems, and then to just lightly water them to give the new growth a boost. Once the leaves and stems are fully formed, water them lightly, and then wait until they only just start to wilt before watering them lightly again. This is the best watering regimen to ensure vigorous growth while minimising rotting.
As you will have gathered, Pterodiscus flourishes in bright, warm conditions. In cool regions of the USA, Asia and Europe, a hothouse would be the place to grow it, or a windowsill receiving full summer sun. In hot countries, though, light shade might prove to result in fresher growth. It cannot stand extreme heat. It can withstand a few degrees below freezing, but only if kept entirely dry for the whole winter. It is best to give it frost protection at any rate.
If you feel up to the challenge of growing Pterodiscus ngamicus, then go ahead! Seed is available by order over the internet. If you live in Southern Africa, you can find seed easily in the veldt. Just wait for the late summer, when the fruits will start drying out and falling off the plants. Plants produce large amounts of fruits, but leave a few so there's enough for a new generation. Let the fruit dry out completely over the winter. Then, the trick is to get the seeds out. Each fruit typically has two seeds, held in a capsule at the centre. You must carefully pull the wings off, which will reveal the seeds at their bases. I use tweezers to take out the seeds; each seed is in a small fibrous 'packet'. You need to be careful when pulling these packets out, not to damage the seeds. Then I lightly rub the seed packets between my fingers, to remove the fibrous outer covering and expose the smooth, shiny seed. Sprinkle the seeds on top of a light, well-draining soil mix, and cover them with a layer of sand of about half a centimetre/0.2" deep. Moisture and warmth should see your seeds starting to germinate in a week or two. I find that actual, penetrating rain is best for boosting the seeds into germination. From there, just nurse your seedlings carefully, especially not overwatering them. They can start to flower in their second season, and will already be handsome little plants.
Perhaps a good idea for general plant health and hygiene would be to re-plant your specimens every two years. Do this at the end of the dormant season. Remove the plants from the soil and carefully inspect their roots and the bases of the stems for any signs of rotting, disease, or aphid infestations. Cut off with a clean knife any diseased or rotting bits, clean the plants, and let them heal for a week or two. Then replant them in clean soil as I described earlier. If you do this right at the start of the growing season, the plants will reward you with vigorous growth.
These plants, if you can keep them alive long enough, will become gnarly-looking specimens. The basal trunk will continue to thicken, and produce short, thick, permanent branches at the tip. There is the potential for training your plants into succulent 'bonsais'. It is at any rate a very rewarding little plant to grow successfully.
