Nursery – Pod 2

Pod #2 – Propagation

At WSBN indigenous plant species are  propagated from collecting seed, taking cuttings or dividing rootballs. Some plants are easier to propagate than others, and Volunteers learn from experienced Team Leaders the most appropriate method of propagation for each plant species.

• Propagation – The process of creating new plants.
• Propagation media – The substance (an organic mix with added nutrients/agents) that seeds or cuttings are placed in for propagation. Potting media is a premix (for natives) that the nursery orders in bulk. Perlite is made out of mined volcanic rock and is highly porous making the pellets able to hold air and water in the potting media.
• Fertiliser – Any material added to the medium to improve the supply of nutrients to encourage plant growth. Fertiliser often is pellets or a powder that are dry and release nutrients that are absorbed by the plants. Other fertilisers are dissolved in water and watered onto foliage.
• Seed-raising tray – A propagation container (tray) specifically designed to be filled with media to hold multiple seeds or small cuttings until the plants are ready for transplantation. 
• Pricking Out – A method of propagation where the seedlings (the plants that have germinated from the sown seeds) are gently lifted from the seed-raising tray and transplanted to a larger forestry tube. The tubes are filled with the media according to the propagation method. At WSBN we mostly transplant seedlings and cuttings into tube pots as our main focus is to sell tubestock plants.
• Tubing Up – A method of propagation where the seedling or cutting is transplanted to a small pot that looks like a tube. You fill the tube with media according to the propagation method.

PROPAGATION MEDIA

Media – The Process

Where the media and containers are stored

The types of containers used for propagation are:

• Seed-raising tray
• Hico tray
• Tubes that fit into the rack
• Polyboxe (foam tub) tub

The trays and tubes are stored on the shelves near the concrete bay or around the back of the Nursery shed. The foam tubs are stored inside the Nursery shed high on the shelves.

The media is kept either in the concrete bay outside (potting media) or inside in a plastic bin (seed-raising media). Any of the products that are added to the media are kept inside the shed.

Please note: Where appropriate we re-use containers, so please ask if you are unsure what a product is.

Watering the media

For most of our propagation methods the media needs to be moist BUT not too wet. There is a hose attached to the outside tap in the media preparation area to water the potting media in the concrete bay and to water the racks once they are prepared and after seedlings have been pricked out or tubed up. Alternatively there are a number of watering cans usually located in the shed…although this can become tedious and heavy if there is a significant amount of seed trays or racks of tubes to be watered. Volunteers generally take a turn at filling the watering cans from the tap outside the shed.

Various propagation methods are used. Each requires different media, trays or tubes.

Media for direct seed sowing

What you need:

• Seed-raising media. The Seed-raising media is ready-to-go, pre-prepared by one of the Nursery Team members and is kept in a plastic rubbish bin inside the shed. It is not the same as the potting media that is stored outside in the concrete bay. As the image below shows, Perlite is added to the Potting media to make a Seed-raising media.
• A Seed-raising tray. Ensure it is clean and fill the tray with the Seed-raising media (stored in a plastic bin inside the nursery) and then importantly settle/firm the media in the tray. No fertiliser is needed.
• A tamper tool. You can use your hand or a place a wooden block/hard plastic pad etc onto the media and press down firmly (tamp) to settle the tray ‘soil’. Seeds that have good contact with the media are well supported when the media is tampered.

Recipe for seed-raising media – Mix of ½ potting media* (from concrete bay outside) and ½ perlite** (from labelled rubbish bin inside shed). No fertiliser is required.

*Potting media is a premix (for natives) that the Nursery orders in bulk. **Perlite is made out of mined volcanic rock and is highly porous making the pellets able to hold water and assists with aeration of the potting media.

Media for cuttings (small into Seed-raising trays or cuttings large into Hicos or Tubes)

What you need:

• Seed-raising potting media. The Seed-raising media is ready-to-go, pre-prepared by one of the Nursery Team members and is kept in a plastic rubbish bin inside the shed. It is not the same as the potting media that is stored outside in the concrete bay. As the image below shows, Perlite is added to the Potting media to make a Seed-raising media.
• A Seed-raising tray or a Hico tray (as guided by a Team Leader or advised in the briefing that is held around the whiteboard to allocate propagating and other nursery tasks at the start of each session.
• Collect the pre-prepared trays or Hicos OR prepare your own. Ensure your tray/Hicos are clean and fill the tray or Hicos with the Seed-raising media (stored in a plastic bin inside the nursery) and then importantly settle/firm the media in the tray OR Hicos. No fertiliser is needed.
• A tamper tool. You can use your hand or a place a wooden block onto the media and press down firmly (tamp) to settle the tray ‘soil’. Cuttings that have good contact with the media are well supported when the media is tampered.

Recipe for cutting media – Mix of ½ potting media* (from concrete bay outside) and ½ perlite** (from labelled rubbish bin inside shed). No fertiliser is required.

*Potting media is a premix (for natives) that the nursery orders in bulk. **Perlite is made out of mined volcanic rock and is highly porous making the pellets able to hold water and assists with aeration of the potting media.

Media for seed sowing of bog plants

What you need:

• Potting media. Potting media is ready-to-go and is stored outside in the concrete bay.
• Foam tubs or or seed-raising trays. Ensure the tub is clean and fill the tub base with Potting media. No fertiliser is needed.

Recipe for bog plants media – Use the potting media and no fertiliser.

Media for pricking out

What you need:

• Collect the pre-prepared racks with the tubes.

OR prepare your own rack of tubes:

What you need:

• Potting media. Potting media is ready-to-go and is stored outside in the concrete bay.
• Ensure the racks and tubes are clean and loosely fill the rack of tubes with Potting media. It is best if the Potting media is not too moist for this procedure.
• Settle this media – bang the rack on the table. The soil will probably drop by about 1-2 cm.
• Now add 8 pellets of slow release fertiliser.
• Fill the tubes up next with the Potting media and then importantly settle/firm the media in the tubes. You can use your hand or the tamper tool. You are aiming to consolidate the media rather than compacting it.
• Water gently your prepared racks of tubes.

Recipe for pricking out media – Use the potting media from the outside concrete bay. Loosely fill the tubes with the potting media, add the slow release fertiliser pellets (approximately 8-10 sprinkled into each tube), fill the tubes with more potting media and tamp the media in the tubes.

Media for tubing up

What you need:

• Potting media. Potting media is ready-to-go and is stored outside in the concrete bay.
• Collect the potting media into a container and take this back to your work bench.
• Collect an empty rack of tubes and a tub of fertiliser pellets. Empty tubes and racks are outside near the concrete bay.
• Identify how much potting media you need to add to the tube* – you may need to ask a Team Leader for guidance as this will depend upon the plant size.
• Add the fertiliser before you backfill the plant provided that it is not added to the very bottom of the tube. Backfill the tube with potting media adding the fertiliser near the top.

* The level of media initially added to the tube will depend upon the size of the plant to be tubed up or divided.

Recipe for tubing up/division media – Use the potting media from the outside concrete bay. Add fertiliser pellets near the top of the tube as you backfill with media.

Media for division of wetland/bog plants – Needs Lorraine review

What you need:

• Potting media
• Fertiliser (blood and bone).

Recipe for wetland media – We generally have a wheelbarrow in the shed labelled and is pre-mixed ready for use. However if you need to prepare a new batch – clean the wheelbarrow first. For a 1/2 wheelbarrow mix 2 teaspoons of blood and bone fertiliser (you will know it, as it is a little stinky) with the Potting media from the outside concrete bay and if you need a full wheelbarrow mix in 4 teaspoons of the blood and bone fertiliser with the Potting media from the outside concrete bay.

Media – Tips for getting it right

• Use the correct media for the propagation method.
• Tamp down the media to secure the plant.
• Identify if fertiliser needs to be added to the media, the type and quantity.
• Wear appropriate PPE when handling fertilisers and other products for making up media mixes.

Media – What can go wrong

• Media is too dry or is too wet.
• Media is watered too hard.
• Media has propagated fungi – some species can be very poisonous and must be removed/disposed of safely (likely that the media batch is disposed of) – seek the assistance from a Team Leader if you see fungi growing in our media.

QUIZ QUESTION – Media: Can you identify which photo below for preparing media for Pricking Out, is in the wrong order. Number ?

DIRECT SEEDING

Direct Seeding – The Process for Seed Raising Trays

This is the most common method of sowing seed and is suitable for a wide range of species.

• Check Murray Ralph’s book ‘Growing Australian Native Plants from Seed‘ for information regarding individual species.
• Fill seed tray with seed raising mix, leaving room to cover the seed to a depth equal to its thickness. Please note: The seed-raising media is ready-to-go, pre-prepared by one of the Nursery Team members and is kept in a plastic rubbish bin inside the shed. It is not the same as the soil mix we use that is stored outside for other propagation such as Tubing Up.
• Gently bump seed tray to settle the media and level the surface.
• Spread seed evenly over the surface — do not sow too thickly (3-5 mm spacing between seeds). Fine seed should be mixed with sand before sprinkling onto the media.
• Sieve a light covering of media (this can be either the seed-raising media or the potting media) over the seeds to a depth equal to their thickness.
• Seeds that need light to germinate only need enough media to bind the seed to the seed tray.
• Label seed tray with batch number, species name and date of sowing.
• Write details into work record book.
• Seed tray must be kept moist but not over-watered.

Direct Seeding – Tips for getting it right

• Spread the seed evenly right to the outside edge of the seed-raising tray
• Sow the seeds in a controlled environment – no wind.
• Sow the seeds of different species well away from another species being sown.
• If a half or three-quarter tray is being sown with another seed species, cover the sown seed before you begin to sow the next species.
• The depth of cover varies between species and so must be covered according to species requirements.

Direct Seeding – What can go wrong

• The Seed is bunched together or sown too thickly.
• The seed is not covered sufficiently.
• Watering after sowing is not gentle causing seed dislodgement
• Inadequate watering through the media held within the Seed-raising tray.

Direct Seeding – The Process for Hicos or Tubes

This is the simplest and most efficient way of sowing seed for those species that are suitable, particularly grasses and those with large seeds.

• Check Murray Ralph’s book ‘Growing Australian Native Plants from Seed‘ for information regarding individual species
• Fill tubes with seed-raising media, leaving room to cover the seed to a depth equal to its thickness
• Gently bump rack to settle the seed-raising media and level the surface
• It is very important to sow the correct amount of seed in each pot
  • Banksia and Hakea 1-2 seeds
  • Acacia, Allocasuarina, Leptospermum and Melaleuca 2-3 seeds
  • Eucalyptus 4-6 seeds
• Cover to a uniform depth with seed-raising media
• Water with a fine spray to prevent splashing or washing the seed to the surface
• Label seed tray with batch number, species name and date of sowing. More later >
• Write details into work record book. More later >

Direct Seeding – Tips for getting it right for Hikos or Tubes

• Sow the correct amount of seed into each pot
• Ensure that media covers the seed adequately

Direct Seeding – What can go wrong for Hikos or Tubes

• Labelling the tray with the incorrect batch number.
• Overwatering causing splashing or washing the seed to the surface.

About ‘Pricking Out’ and ‘Tubing Up‘

The next two methods of propagation are common activities where our new Volunteers may take part. They are really important and need to be done carefully, following the process that your Team uses. If you are not sure, please ask for a demonstration. A slow methodical approach is better than trying to be quick and propagate many plants.

Commonly called ‘Pricking Out’ (Po) or ‘Tubing Up’ (Tu) these are two common methods for transplanting the seedlings as they grow. This is best done as soon as possible after the seedlings have germinated. A Team Leader will decide on the timing of these activities and it will be discussed during the morning briefing. Transplanting seedlings after they have germinated in the seed-raising trays is particularly important for trees and shrubs where it is essential that the root system does not become kinked.

A seedling that continues to grow with kinked roots will result in a weakened specimen that is likely to fall over once planted. A critical action when transplanting seedlings either by the ‘Pricking Out’ or ‘Tubing Up’ method is to try and drop/position the roots into the tube as straight as possible. It can be helpful to dip the seedlings roots into a glass of tepid water to help gain this vertical alignment.

The tubes for ‘Pricking Out’ and’ Tubing Up’, have ridges on the inside designed to stop the roots from circling.

Hygiene: If there is doubt as to the hygiene of tubes etc. that are being recycled they should be soaked in a 1:20 solution of household bleach for 30 minutes, then dried and aired before use.

PRICKING OUT

Pricking Out – The Process

Pricking Out a seedling from the seed-raising tray should be done as soon as possible after germination to allow for good root development.  This delicate job is very important to get right and is an occasion when slow is good. The seedlings at this stage are very fragile as the photos below show and need to be handled gently.

Pricking out is the preferred propagation method for shrubs, grasses and wildflowers.

Generally the racks with the tubes for ‘Pricking Out’ propagation have been pre-prepared by a Nursery Team member. Look for the pre-prepared tube racks on the trolley outside the shed or some may also be stored on racks next to the external sink.

Empty tubes and racks are stored outside near the concrete bay or behind the nursery shed if there are no prepared tubes and you need to prepare some yourself.

• Fill rack of tubes with potting media and fertiliser according to procedure.
• Water thoroughly to eliminate any air gaps and make sure that the potting media does not fall out the bottom of the tube. This is important to prevent the tubes from drying out and becoming water repellent in the future.
• Using a ‘dibbler’ stick make a hole deep enough for the roots in the centre of the tube.
• The dibbler is also used to gently ease the seedlings from the seed tray, using the other hand to grasp the seedling, which is then carefully lowered into the hole made previously.
• If the roots are long they can be pruned back by a third to a half of their length using a fingernail or scissors.
• Once the seedling has been placed in the tube so that it emerges at the same level that it was in the seed tray, the media is gently firmed around the roots.
• Label rack with batch number (more on this further in your training), species name and pricking-out (p.o.) date.
• Write details into work record book.
• The rack of tubes is gently and thoroughly watered before going into the polyhouse to establish for the next few weeks.

Pricking Out – Tips for getting it right

• Ensure that the potting media does not settle too low into the tube – top up if pots have media levels such as in some of the pots shown in the image below.
• Seedlings with very long roots can be trimmed.
• Use a dibbler tool (knitting needle) or other thin sharp tool to gently prise tiny fragile seedlings from the Seed-raising tray.
• Dip the seedling roots into a jar of tap water to assist with ‘detangling’ and assessing root health and length of roots – this can help you to guide the fragile roots into the hole you make for the seedling to be transplanted into to.

Pricking Out – What can go wrong

• Seedlings are not planted deeply enough in the tube.
• Throwing away a Seed-raising tray without first checking with a Team Leader – some seedlings germinate over time and ’empty’ trays can go back into the igloo to encourage additional germination.
• Roots are damaged on retrieval
• Roots are handled too roughly as they are transplanted causing damage or irregular growth direction.

This is a slightly easier procedure than that for some trees and shrubs. The same racks and tubes are used for most of the wildflowers but polyboxes may be used for wetland plants.

TUBING UP

Tubing Up – The Process

The reason for Tubing Up a seedling reduces the chance of the roots kinking or tangling. The seedling is held at the top of the tube, with the potting media poured around it pulling the roots down as it fills. The media will pour more easily if it is not too moist.

Tubing Up is the preferred propagation method for trees, large shrubs and cuttings.

If you are ‘Tubing Up’ you will prepare the tubes yourself as the amount of media that is required to be added firstly is dependant upon the size of the seedling.

What you need for ‘Tubing Up’: Collect a container for the potting media which will be used at your workbench. The potting media is stored outside in the concrete bay. Collect a tube tray and fill with the same type of tube pots. Collect a small container with fertiliser pellets and another with water to dip the seedling roots in if they are entangled. You should also have a sharp pair of secateurs and a dibbler (knitting needle) that you can use to trim excess roots with and detangle roots.

This delicate job is very important to get right and is an occasion when slow is good.

• Fill rack of tubes with potting ‘soil’ loosely. It is best if the potting media is not too moist for this procedure. Usually you add an amount of media to the tubes first, but the amount varies depending upon the length of the seedling. Ask if you are unsure.
• Remove seedling from tray using a dibbler stick.
• Hold the seedling over the tube so that its roots are straight (they may need pruning if they are too long — use fingers or scissors).
• Dip roots into a container of water so that the roots have no dirt on them and are all straight (easier to get into hole in tube) This is especially important for eucalypts so that the roots are straight and the seedling is straight in the tube.
• Back fill the tube with media, making sure that the roots are not kinked in the process. If the roots are kinked at this stage the tree will not grow strong enough to support itself when it is planted and all the time and effort will have been wasted.
• Add 8 pellets of fertiliser as you are backfilling media around the plant, closer to the top of the tube. The pellets should still have a cover of media, so that they are not washed away when the tray is watered.
• Plants must be tubed up to the same depth as they were in the seed tray. E.g. All roots covered with the media.
• Label rack with batch number, species name and tubing-up (t.u.) date.
• Write details into work record book.
• The rack of tubes is gently and thoroughly watered when they are placed on the trolley.
• When the tray has been watered you can move it to the benches near the rear shed door.
• A Team Member will use the trolley to take the trays/racks to the igloos – it is important to group your plant trays on the bench to help this Team Member gauge how much stock is coming through and needs a ‘spot’ in the igloo or nursery yard.

Tubing Up – Tips for getting it right

• Handle the seedlings gently to avoid damaging stems, root stock and leaves.
• Trim roots to fit the length of the tube so that they fit the tube without being bunched up.
• Hold the seedling so that it is potted in the middle of the tube as you backfill around the roots.

Tubing Up – What can go wrong

• Seedlings are not planted deeply enough in the tube.
• The seedling is planted too low in the tube.
• Forgetting to add fertiliser pellets before the seedling is back-filled.
• The roots of the plant are kinked having not been positioned into the tube correctly.

A sad Eucalyptus:

The image below shows a Eucalyptus tree that has been tubed up with its roots not positioned into the tube correctly. As a result it has grown with its roots twisted and the trunk is not viable as it is not growing vertically. This is why it is very important to tube up the plants with their roots straight.

The dotted green line shows the correct vertical position for the plant. This plant would be discarded as the root/stem has not established vertically as per the green doted line shown below.

CUTTINGS

Cuttings – The Process

Cuttings are used to propagate plants that are difficult to propagate from seed. Being a vegetative means of propagation means that all the plants produced will be identical to the parent plant, so from a biodiversity perspective it is important to collect plant material from as many specimens as possible.

Cuttings are best collected early in the morning when the weather is cool. Collect cuttings into a plastic bag and keep moist with a water spray at all times. If the cuttings are not to be prepared immediately they can be wrapped in damp newspaper and kept in a plastic bag in the coldest part of the refrigerator (around 3°C) for up to 2 weeks.

Stem/tip cuttings

The best place to collect stem cuttings is from juvenile foliage as close to the base of the plant as possible.

The type of cutting depends on the season:

• Semi-hardwood cuttings are collected in late summer/autumn e.g. Correa.
• Hardwood cuttings are collected in winter.
• Softwood cuttings are collected in late spring e.g. Correa.
• Herbaceous cuttings are collected anytime e.g. Tetragonia implexicoma.

Preparation of cuttings

• Prepare a container (usually a seed tray) and fill with seed-raising mix; an open mix that provides the necessary drainage and aeration for cuttings. Moisten if necessary before preparing cuttings.
• For most stem cuttings, the tip of the stem will make the best cutting. If material is scarce it is usually possible to use material further back from the tip, although this may result in slower and lower rates of rooting as well as a variable type of cutting.
• The length of the cutting will depend on the length of the internode (the part of the stem between each leaf base). Usually cuttings are made from three nodes and the cut is made just below a node as this is the area where root formation is greatest. However, in species where the nodes are close together, more than three nodes may be used.
• If the shoot tip is very soft it may be pruned to just above a node and then the next three nodes form the cutting.
• Generally, between a third and two-thirds of the leaves are removed from the stem (more if it is very hot to avoid heat stress).
• Leaves are usually not reduced in size as this can facilitate entry of pathogens.
• The base of the cutting is dipped into a root promoting hormone (auxin), which may be in the form of liquid, powder or gel, allowed to dry for a minute or so and then gently placed in a hole made with a dibbler.
• The cuttings are placed into propagation mix in the seed tray.
• Label rack with species name and date of cutting.
• Write details into work record book.
• Once roots have formed the cuttings are tubed up into potting media and moved into the polyhouse to harden up before moving outside.

Reference: Stewart, Angus, 1999. Let’s Propagate! ABC Books, Sydney, NSW

Cuttings – Tips for getting it right

• Make your cuttings while the material is still fresh.
• Have an experienced team member demonstrate how to make the cutting for the species.
• Use a growth hormone to stimulate the cuttings growth – soak end in mix prior to inserting into medium.
• Trim away flowers, flower buds and excess leaves to encourage root growth.

Cuttings – What can go wrong

• The cutting has been made from an incorrect position along a stem or branch.
• The cutting is not long enough to securely ‘sit’ in the seed-raising trays.
• Secateurs are blunt and this damages the cutting.

DIVISION

Plant material salvaged from a wetland site may need to be divided into tubes or small pots as a clump. Sometimes grasses and sedges outgrow their tubes and may be divided to make more plants. Usually the root system is very strong on these plants.

Division – The Process

• Use secateurs, a knife or other implement to divide plant
• Make sure there is some root material on each new plant
• Remove weeds – sometimes implements such as knitting needles can be useful to gently extract the weed from the plant roots
• Follow directions for tubing up*
• Label tray/rack with species name and date of division – Explained in more detail further on
• Write details into Work Record Book – Explained in more detail further on

* Sometimes wetland plants may be propagated as a small clump into pots – you will be advised on the day what the preferred method will be for a particular species – sometimes this decision is influenced by the location for the re-vegetation

Division – Tips for getting it right

• Each plant must have at least one root.
• If the plant has outgrown the tube – trim off excess root material.
• Trim away dead foliage and cut back healthy foliage as appropriate.

Division – What can go wrong

• Insufficient root system.

Each week the Nursery Team during propagation season, produce many racks/trays of plants. The care and storage of these plants is a vital component of the Nursery activity. Look for the Team members who are busy ‘behind-the-scenes’, ensuring that there is good stock control and that the plants are stored appropriately.