Published 23 May 2023 by Georgina van Biljon
Palmiet (Prionium serratum) is greatly valued as a key ecological species in SA freshwater ecosystems. It is endemic from the Western Cape up to southern KwaZulu-Natal in South Africa. Intaba uses palmiet extensively for restoration purposes in river ecosystems. It is a landscape definer and can greatly boost the ecological 'currency' of ecosystem services. Palmiet can also be seen as a 'keystone' plant specie in restoration, however it is only part of the solution. We need a vast variety of species to undertake restoration, but in this article we will be trying to divulge all of its secrets!
In this post we will be sharing 1) it's ecological benefits; 2) how to propagate it, 3) planting palmiet and 3) how to prepare it as a tasty meal.
Other references and useful links are shared at the end of the post. If you are going to use any of the information, we ask you please to attach our website link and give credits to photos please. Please do not use any photos or information for publications.
Photo: Palmiet stand near the Waterval Nature Reserve, Tulbagh, South Africa. (credits: Johann van Biljon)
Ecology
Palmiet's plant anatomy is described below.
Palmiet is a robust shrub to 2m tall, with lanceolate leaves that are crowded at the tip of the stem and sharply serrate on the margins. The stem is fibrous and the leaves sclerophyllous. It is a riparian species that is mainly found along streams and rivers, often forming dense stands. The name ‘palmiet’ derives from its similarity to some palm trees – which are also monocotyledons. (Manning & Goldblatt 2012)
Palmiet wetlands can seem like an impenetrable mass of plants that look like palm trees. In some ways they resemble a palm tree with their sharp-edged leaves that are in a fan shape. Their stems are flexible and can handle high floods. They are aquatic plants occurring in fresh water, rivers and wetlands.
Photo: Johann van Biljon lying in a dense stand of palmiet. (credits: A. Rebello)
Palmiet has a very high root to leaf ratio, as seen in this photo above. The roots are more than two times the length of the leaves. This is a great advantage of the plant in establishing itself in the ground, so that when there is high river flow then the plant will not be washed away.
Palmiet roots can form dense mats and an excellent habitat for aquatic organisms (see photo above) (credits: J van Biljon).
Palmiet is a palatable (edible) plant for livestock and in the photo above you can see the plant's leaves on the left of the fence are eaten and on the right, the plants remain intact. Photo taken near Riversonderend (credits J van Biljon).
Value in restoration
One of the main problems in the main rivers in the Western Cape, South Africa is the increasing channelisation and deepening of the rivers, thereby increasing their speed and erosion potential. Palmiet can potentially buffer such impacts by reducing the flow, increasing deposition, improving water filtration and binding the soil.
Propagation
Palmiet is mostly grown for restoration purposes, but can also be used in landscaping (Patrick Watson, a reknowned Landscaper used palmiet in the development of Sun City) and also in dams and large ponds. Propagation methods for palmiet include in-situ cuttings and germination from seed. Intaba and some other growers have experimented with these methods and have optimised the process to maximise propagation rates.
In Boucher & Withers (2004) article on palmiet in the March 2004 Veld and Flora, they used branches of palmiet to restore some areas of the Du Toitskloof pass. This may be done by cutting off ‘branches’ of Palmiet (0,5-1m lengths) using a hand saw, sickle or panga, into the ‘hard wood’. Cuttings can either be rooted in ponds or placed directly after making the cutting into a hole in the river’s edge and can be secured by placing rocks strategically at the base or using rope. However, this is not always necessary, as successful establishment depends on the time of planting and flow regime of the river. Planting of cuttings are more successful when the water level of the river is low. This gives the palmiet cuttings enough time to establish their roots before the next flood or high flow event.
This method of growing palmiet can be very labour intensive, but one can have a fairly large plant growing in a short time. This method is useful if you do not have propagation facilities and are only trying to grow a small quantity of palmiet. For producing larger quantities of palmiet it is better to propagate them from seed.
Photo above: cutting of Palmiet that has developed roots.
Photo above: Palmiet plant developing side branches from a thinker stem. (credits: J van Biljon)
SUMMARY: using in Situ cuttings
Use a handsaw, sickle or panga to cut off palmiet branches about half a metre to a metre long.
Root the cuttings in ponds or plant them into holes at the river’s edge, using rope or strategically placed rocks to secure them.
Your cuttings will be more successful if you plant them when the water level is low because this gives the cuttings enough time to establish their roots before the next flood or high-flow event.
Propagation from seed:
There are a few steps in this process: seed collection, processing and germination of seeds. Seed collection mostly occurs in the summer months from November to January. One needs to monitor the Palmiet seed head development as the ripening and release of seeds can occur within a narrow time period. This timing varies from location to location and also from year to year. An ecological restoration principle is to harvest seeds within the same river catchment where you are planting, so as to ensure genetic integrity is maintained.
Photo: a seed head of Palmiet near Riversonderend. The palmiet in the background were recently burnt and are re-sprouting after fire. (credits: Johann van Biljon)
Photo above: A palmiet seed head that has opened. (credits: J van Biljon)
Photo above: A palmiet seed head with seeds inside - photo has been enlarged. (Credits: J van Biljon)
Once the seed heads have been harvested, they need to be dried on racks (out of the wind, as the seeds are very fine and can blow away). The seed heads should open as they dry and release the seeds. One can chip the seed heads and then sieve the mixture to clean the seeds from the fruit capsule fragments.
Photo: Palmiet seed on a knife tip. (credits: Johann van Biljon)
Seeds can be sown onto the surface of a moist medium in seed buckets or germination trays. Peat seems to get the best results as a growing medium, as it retains the moisture very well. Alternatives to peat still need to be investigated! The seedlings need to remain moist, so keeping them in a tunnel or covered with clear plastic bags can assist this process. From sowing of seeds to germination it can take 5-7 days.
Once the seedlings are 1cm in size, they can be individually transplanted into larger seed trays (See photo of 128 cavity seed tray below). Or larger seedlings can be placed in potting bags in an acidic, sandy medium.
Photo: Seedlings of palmiet showing different root formation patterns. (credits Johann van Biljon)
Photo above showing palmiet growing in bag. (credits: J van Biljon)
SUMMARY: Sowing from seed
Follow the ecological restoration principle of harvesting seeds within the same river catchment where you are planting to ensure genetic integrity.
In summer, between November and January, monitor the developing palmiet seed heads because the seeds ripen and are released in a narrow time period that varies from location to location and from year to river.
Dry your harvested seed heads on racks out of the wind – the seeds are very fine and can blow away.
The seed heads open as they dry and release the seeds. Clean the seeds of fruit capsule fragments by chipping the seed heads and then sieving the mixture.[V&F1] [GvB2]
Sow the seeds on the surface of a moist growing medium – peat gets best results – in seed buckets or germination trays.
Germination usually takes five to seven days.
Keep the seedlings in a tunnel or covered with clear plastic bags to help them stay moist.
Once the seedlings are one centimetre high, transplant them individually into larger seed trays.
Larger seedlings can be placed in potting bags in an acidic, sandy medium.
Plant the young palmiet plants along riverbanks in the river bed or in wetlands in late spring or at the beginning of summer when the water is low or has dropped after winter rains. This helps roots establish themselves and reduces plants lost due to flooding.
Within only a few weeks after planting, even small palmiet plants can withstand higher water flows thanks to their highly developed root structure.
Planting
Palmiet plants can be planted out in river beds or wetlands at the river’s (water) edge when the water level is low or has dropped after the winter rains. If this is done at the beginning of Summer or late Spring (at the onset of the dry season), then this will assist with root establishment and reduce plant loss caused by flooding. Even small palmiet plants can withstand higher flows only a few weeks after planting, due to their highly developed root structure.
When planning palmiet re-introduction to ecological systems (wetlands, rivers and water ways), it is best to involve a wetland ecologist. One should consider active restoration involving a balanced mix of plant species that belong in that catchment and freshwater ecosystem. Flow (hydrology) and geomorphological aspects of rivers need to be considered when choosing appropriate sites for planting palmiet in riparian ecosystems.
Photos above are palmiet cuttings that were planted at Boschendal Wine Estate near Franschoek in order to stabilise the eroded river banks that have been undercut. Rocks were placed ontop of the 'branches' of palmiet to keep them in place. (credits: J vanBiljon)
Photo above is taken at Bosplaas Farm, Berg River, South Africa. (credits: J vanBiljon)
Planting of Palmiet on steeply eroded banks requires safety precautions at times. Ropes and life jackets may be needed. We preferably plant palmiet when the water level is low to avoid this risk.
Palmiet meal
Palmiet can be eaten raw or cooked. Here is a video of how you can eat it raw (credits: J van Biljon).
Cooked palmiet
Tools: panga or sickle, steamer pots, frying pan.
Ingredients: palmiet, onions (2-3), garlic cloves (3-4), soya sauce (1Tbs).
Method: Harvesting palmiet
Palmiet can be harvested all year round. Cut sections of about 1m long from the growth tip down. The part that one eats is the growing tip. Use the panga or sickle to cut through the palmiet branch. You will need 3 to 4 palmiet branches with growing tips.
Make sure you harvest sustainably. Do not take more than about 15% of the palmiet bush at a time. Do not go back to the same plant within the same year. Rather harvest from places where there are dense stands/an abundance of palmiet. Make sure you have permission from the landowner before you harvest. Be aware the removal of a branch can have an influence on the flow of the river. Do not harvest palmiet where it is helping to stabilise riverbanks or water courses.
Preparation for cooking
Cut off or strip off all the outer leaves until you get the soft growing tip. Use only the soft middle growing shoots for cooking. Cut the excess of the stalk off. Wash thoroughly. If you want to kill all germs, wash the palmiet in a highly diluted bleach solution and wash thoroughly afterwards with clean water.
Cut the shoot (growing tip) into 3-5cm size pieces.
Slice up the onions (2 -3) and garlic (3-4 cloves).
Steam the palmiet until soft.
Pan fry the onions, garlic in a vegetable oil until golden and soft if you prefer caremalised onions, use a low heat. If you prefer stir fry, use a high heat and cook the onions first, then add the garlic towards the end. Otherwise the garlic becomes bitter if it is overcooked. Add the steamed palmiet shoots and 1-2 Tbs of soya sauce.
Serve with rice or other stir fry vegetables, meat.
Cooking time +-20mins
Enjoy your culinary adventure!
References
Charlie Boucher & Melanie Withers, ‘Palmiet: Prionium serratum, a Cape river plant’, Veld & Flora, March 2004, pp.26-28: https://pza.sanbi.org/sites/default/files/info_library/palmiet_pdf.pdf
Alanna Rebelo, ‘Mapping palmiet wetlands’, Veld & Flora, December 2018, pp.168-172: https://journals.co.za/doi/epdf/10.10520/EJC-1507e27d82 (subscription)
John Manning & Peter Goldblatt, Plants of the Greater Cape Floristic Region. 1: The Core Cape Flora (SANBI, Pretoria, 2012), Strelitzia 29[V&F1] [GvB2] : https://www.sanbi.org/sites/default/files/documents/documents/strelitzia-29-2012.pdf
To volunteer with Friends of the Rivers: http://friendsoftheriversofhoutbay.co.za/
Nurseries growing palmiet
Intaba Environmental Services (Tulbagh)
Worcester Field Reserve: https://www.elsenburg.com/worcester-veld-reserve-research-farm/
Spier Nursery: https://www.spier.co.za/growing-for-good/the-spier-nursery
ZWUA (Zonderend Water Users Association, Genadendal): johannesarendse@gmail.com or lana@zonderend.co.za