fThis seed collection and propagation guide is a short version of Ecosourcing News, a newsletter produced by Ecosourced Waikato to alert native plant growers to seed availability.
Although originally developed for the Waikato region, it has wider application as many of the native trees and shrubs are found throughout New Zealand.
The information should be read in conjunction with the calendar for seed collecting (grasses, lilies, flaxes, epiphytes and climbers).
For help with plant identification see:
Astelia grandis/swamp astelia
Growing to over two metres tall in ideal conditions, this, the largest of New Zealand’s astelias, is most commonly found in wetlands. It grows equally well in dappled shade and full sunlight and doesn’t seem to be the least daunted by waterlogged soil which stunts most other species.
Secateurs are useful for collecting the rather tough seed heads covered in yellow/orange berries in early autumn.
Propagation: Wash the seed and sow on a firm bed of seed raising mix. Seed sown in autumn should germinate in early spring and be ready for potting in summer. Once potted, the plants do well with their containers placed in a shallow trough of water.
Kahakaha grows perched up in trees where it sacrifices good soil for ample sunlight. It is recognisable by its fan-shaped leaves from a dark brown base. The seeds are found in bright orange fruit which ripens around March.
Propagation: Soften the fruit, mash and wash out the seeds. Sow on a firm bed of seed raising mix, cover lightly with mix, water well, cover with glass or plastic and place in a warm shady place. Germination can take several months. Remove the cover when seedlings appear.
Austroderia fulvida and Austroderia splendens/toetoe
These tussock-forming grasses grow wherever poor soil conditions mean that they have little competition from other plants for sunlight. This can range from wetlands and steep river and stream banks for A.fulvida to eroding coastal cliffs and coastal wetlands for A.splendens. (Be aware that two invasive species of pampas are also good at occupying similar spaces). Toetoe flower early summer, A.fulvida earlier than A.splendens, and have a much droopier appearance than pampas. The white fluffy seeds start to shed from the flower head from about Christmas on with some seeds persisting until autumn.
Propagation: Shake the seed heads into a large bag and then spread the seed over a firm bed of seed raising mix. Cover lightly with mix. The seeds need light to germinate and can be up within 7 – 10 days but frequently take longer.
Carex secta and C.virgata/purei
These two species of sedge are commonly found in wetlands, both growing in open sunlight or light shade in wet soil, tolerating water to a depth of 300 to 400 mm. The roots of Carex secta can form a trunk-like structure, making the individual plant up to 2 metres tall. The seeds are borne on long spikes – upright in Carex virgata and more pendulous in C.secta. Seeds ripen in late summer and are dispersed by floating on water.
Propagation: Be careful when stripping seeds from the seed head as leaf margins can be sharp. Sow on firm seed raising mix and cover lightly with mix. Germination can be a few weeks in warmer temperatures but slower in winter.
Carex uncinata/hook sedge
There are many species of hook sedge with this one mainly frequenting damp shady places. Flowering spikes can be seen from August to December with seed ripe February/March – when it will often attach itself to trampers socks.
Propagation: Press the seed into a firm bed of seed raising mix and water well. Cover with glass or plastic and place in a shady place until the seedlings appear in the spring. Remove the cover and bring out into the sunlight.
Puawhananga is a climber, growing up tall trees to get its leaves and flowers into the sunlight. It is easily identifiable by masses of white flowers in early spring and that is the place to return to in December/January to locate seed. Seed is contained in a silky feather-like cluster and is quickly dispersed by the wind.
Propagation: Seed should be sown as soon as collected, with or without the feathery styles. Remove from the base and spread on a bed of firmly packed seed raising mix and cover lightly with mix. Germination is usually within 2-3 months but can be erratic.
Cyperus ustulatus/giant umbrella sedge
This sedge grows equally well in waterlogged and well drained sites but responds well to nutrient rich soil. It is commonly found in roadside drains and is particularly common near the mouth of coastal streams. Seed is produced prolifically in clusters at the top of spikes and can be collected in late summer and shaken into a large bag.
Propagation: Sow onto seed raising mix, cover lightly with mix, pumice or vermiculture and water generously. Seedlings germinate freely under almost any conditions.
Dianella nigra/turutu and D.haematica/swamp blueberry
Dianella species can be found in a variety of places where the soil is too poor to support other plants. Dianella haematica is a plant of peat bogs and swamp margins whilst turutu is most likely to be found on forest ridges. The distinctive blue berries ripen around March and fall off at the slightest touch.
Propagation: Soften the fruit, wash and decant off the pulp leaving the tiny black seeds behind. Sow on a firm bed of seed raising mix, press into the surface and cover very lightly with mix.
Kiekie is a scrambler found on both the ground and tree trunks and in both damp shady places as well as full sun where there is sufficient moisture in the ground. The flowers appear in spring and the fruit is ripe the following autumn or winter. However, plants appear to fruit and flower only occasionally. The fruit is soft and syrupy under a hard shell with large numbers of tiny seeds.
Propagation: Wash the seeds and decant off the pulp and syrup. Press the seed into a firm bed of seed raising mix, water and cover with plastic or glass. Place in a warm shady place until the seedlings appear then remove the cover and bring seedlings into the sunlight. Germination may take several months with the seedlings not ready to prick out for year.
Gahnia species are colonisers of low fertility soils. Gahnia setifolia is commonly found on clay banks as is G.lacera although the latter is more tolerant of exposed coastal conditions. G.pauciflora is common on leached soils of ridges whilst G.xanthocarpa is a characteristic plant of swamp forest, tolerating wet, sunny conditions. Seeds tend to persist on the flower spikes of these sedges, clinging to the old filaments until really mature.
Propagation: Sprinkle the seed on a firm bed of seed raising mix, cover lightly with mix and then with plastic or glass. Place in a warm shady place until seedlings appear and then remove the cover and bring out into the sunlight. Seed can take up to a year to germinate and the seedlings are quite slow to grow as well.
Machaerina are a group of rush-like wetland species tolerant of wet and sometimes waterlogged soil. Machaerina articulata grows in water to a depth of 300 mm with other species found on the margins of water bodies. Flowers are on panicles at the top of stems and the seeds are tiny and nut-like. All mature in the autumn.
Propagation: Sprinkle the seed over a firm bed of seed raising mix, cover lightly with mix, water and cover with plastic or glass. Place in a warm shady place until the tiny seedlings appear (in about nine months); remove the cover and bring out into the sunlight.
Metrosideros diffusa and M. perforata/akatea
Both of these species of white rata are climbers, especially found clinging to tree trunks but also some times on rocks and old logs. The flowers appear in late summer/autumn and the capsules containing large quantities of tiny thread-like seeds dry out in the winter. Seed can be collected by holding an envelope under the capsules and gently tapping, collecting the seed as it falls. Alternatively, collect green capsules and store in a warm dry area until they open.
Propagation: Sprinkle the seed on a firm bed of seed raising mix, water and cover with plastic or glass. Place in a warm shady place until seedlings appear. Remove the cover and bring out into sunlight. Germination may take several months and the seedlings may not be ready to prick out for a year.
Microlaena avenacea/bush rice grass
Because of its vulnerability to drought, bush rice grass is mainly found in the shade of the bush, especially at higher altitudes or stream sides where the air is moist. Once the green of the seed heads start to fade in late summer it is time to collect the seed.
Propagation: Strip the seed off the flower heads and press into a firm bed of seed raising mix and lightly cover with mix, pumice or vermiculture. Seedlings begin to appear in later winter or early spring - do not let them dry out.
Found particularly on stream and river terraces, kaihua forms a tangled thicket, often scrambling over shrubs and low trees. The waxy white flowers have led to it being referred to as NZ jasmine. Once flowering is finished, a mass of thin bean-like pods remain dangling from the scrambling runners. These dry out, turn black and split longitudinally.
Propagation: Separate the down covered seeds from the pods, spread over a firm bed of seed raising mix and lightly cover sufficient to bury the fluff. Place in a shady site until the seedlings appear in the spring. When potted, the seedlings require a stake to wind around and grow over.
The orange fruit of kohia can often be found on the ground under the vines – if it hasn’t been consumed by rats and mice. This vigorous climber has the potential to scramble right to the top of tall kahikatea trees and can shade out other trees so should be used sparingly in a restoration project. However, this vigour can be useful to fill a space in the forest where a tree has fallen. Collect the fruit in late summer/autumn.
Propagation: Remove the seeds enclosed in the dry pulp, press into a firm bed of seed raising mix and cover lightly with mix. Seedlings appear in spring and should be potted on with a tall stake or tripod of stakes to allow for the vigorous growth.
Phormium tenax/harakeke and P.cookianum/wharariki
These two species of flax are well adapted to growing in poor soils. Harakeke will grow from wetlands to exposed cliffs but not in the shade of the forest whilst wharariki prefers dry places, including steep cliffs. The seeds are produced in long, pendulous capsules which twist then split open to reveal dry, black seeds around February/March. Cut off the pods before they open and store in a paper bag in a warm dry place.
Propagation: Sow seed on a flat firm bed of seed raising mix and lightly cover with mix. Seed usually takes about two months to germinate depending on temperature.