The crew from John Holland and Melbourne Water are working in the park on the major task of duplicating the sewer under the Yarra River – a project to be completed in 2024. They took time out this week to see more of the park and to help out with spring planting.

Thank you to George and the team for having us out onsite planting today. Thankfully the weather held off and we got to enjoy some sunshine out in the beautiful Westgate Park.

Thanks again for helping to coordinate the day – we all had a great time.

Bec

People often turn a cheek to the saltmarsh, it has rarely captured interest in the same way our forests or flowering heathlands historically have. The slippery sedimentary soils, blaring heat and occasionally offensive odours don’t lure the passer-by, but the appeal is real.

Bands of colour and texture stand out as plants conform to their tolerable zones, these arrangements delicately defined by the conditions and the unique adaptations of constituent species. The prime adaptation of these plants is their ability to manage otherwise harmful levels of salt in their tissues, and for this they are referred to as halophytes, translating to salt plants. Classifying these plants is ambiguous but for the sake of providing context, one definition made is that halophytes are plants that survive to complete their life cycle in at least 200 mM salt. Under these conditions, all halophytic species have to regulate cellular Sodium, Chloride, and Potassium ions, but the pathways involved vary, and are not completely understood. Straying from the molecular level, some of the visible adaptations are the ability of plants to excrete salts to external bladders on their leaves as seen in our local Atriplex cinerea or compartmentalise it in vacuoles of succulent leaves like in Suaeda australis. Both of the aforementioned plants are in the family Chenopodiaceae, which has the most halophytes of any other plant family with an estimated 381 species.

Our saline lake and lagoons at Westgate Park provide conditions for a number of dycotyledonous and monocotyledonus halophytes. These plants survive in isolation of the dynamic interplay between upland freshwater flows and coastal saltwater influence. This hydrological flux is considered critical to the functionality of coastal saltmarsh systems and so our saltmarsh does not function in the way true Coastal Saltmarsh would, instead being more like Australia’s inland salt lakes. Nevertheless, this site provides habitat for a number of birds including Black-winged Stilt, Dotterels and other waterbirds such as the Chestnut Teal.  The plants here also give an insight into the history of the area and the remnant saltmarsh that occurred at the mouth of the Yarra River up until the early 2000s only a few hundred metres away at Webb Dock. 

A Coastcare Victoria grant gifted to our organisation from DELWP has provided the opportunity to engage our volunteers with these specially adapted plants. 

Volunteers have undertaken supervised seed collection of species including Streaked Arrow-Grass Triglochin striata, Rounded Noon-flower Disphyma crassifolium, Sea Rush Juncus krausii, Blackseed Glasswort Tecticornia pergranulata and Austral Seablite Suaeda australis. 

These have been germinated at the nursery and will be grown-on by volunteers to be planted back at the park, where weed control works targeting the noxious Spiny Rush Juncus acutus are underway. We have also been propagating cuttings of Creeping Brookweed Samolus repens that was saved before the development of the docks and has survived in stock boxes at the nursery since. Building on past revegetation works will continue to improve the aesthetic and ecological value of the site known to many as the Pink Lake. 

We will be continuing our work on this project for some time, so if people are interested in getting involved please reach out.

For those interested, a great local example of coastal saltmarsh similar to what would have occurred at Westgate where the Yarra meets the Bay can be found at Altona Coastal Park and is well worth a visit.

Holden Sayers, WBBNL staff

Some of our indigenous plants are grown by cuttings or division but most are propagated from seed.

Preparing seeds, or seed cleaning, is a hugely important role in our propagation process. But all it requires is an aptitude for careful and methodical work, guided by our staff, and a regular commitment to spending time with the team in our nursery at 525 Williamstown Road, Port Melbourne.

Your reward is to see your seeds germinate, grow into seedlings and be pricked out into tubes.

You will know these seeds will become plants – tall trees, shrubs, wildflowers, sedges, grasses, groundcovers, and more – and that your efforts are making a difference, making Melbourne and the Sandbelt Region more biodiverse!

Here’s how to let us know you are interested:

A few things to know about seeds

Not all indigenous plants are easy to propagate. Some are dormant for a period, others have evolved to germinate only after fire. Some need prolonged rain, others are quick to release their seeds making capture difficult.

Seeds are immensely varied in size, shape, method and time of dispersal. Most seeds have a protective coating, sometimes hard and woody. We use treatments like washing and soaking, ‘smoke water’, gentle sanding to remove all or part of the seed coat, periods of dry storage, hot or cold conditions or natural weathering.

Seeds can have papery ‘wings’ that make them more readily airborne or hairs or spikes to anchor the seed to the ground or a host.

Not all seed produced is viable and there is great diversity in time taken to ripen and the length of time seeds are viable after maturity.

For some species, germination is improved by the seed passing through the digestive system of an animal and this can be highly species-specific such as Ravens and the fruit of Alyxia.

Seed cleaning

• Cleaning means separating the seed from everything else (pods, chaff., sticks and leaves).

• You need to be sure you know what the seed looks like so you don’t keep the chaff by mistake.

• For some species it’s possible to pick out the seed by hand

• For others, hand sieves can be used to separate the seeds from everything else, using the right mesh size to catch the seeds on a sheet placed underneath.

• Gentle blowing will remove the lighter chaff from the seed

• Vibrating or shaking the seeds in a dish can help separate seeds

• For grass species sometimes threshing or beating works best.

Storing seed

• Seeds must be dried, weighed and sealed in airtight containers – glass jars with metal screw tops best protect the seeds from voracious mice and insects – and jars labelled for genus, species, date and location of collection, collection and drying method used, weight of seeds.

• Seeds should be kept in a cool dry location away from direct sunlight.

• Before storing, remove any seeds that show signs of insect damage, mould or fungus. Insect attack may appear as small holes in the seed or as a webbing over the seeds. Another tell-tale sign of insect presence is powder in the bottom of the container.

• Check regularly to make sure seeds are insect-free. It is possible to kill insect pests using carbon dioxide, moth balls and rat bait. Keep records of checks and treatment used.