Beech Seed Collection

A key consideration in what seed to collect, other than what is suitable for the site, is what is actually going to be locally available. Restoration projects should seek to use seed collected from plants that naturally occur in the area and should avoid using seed stock from outside of the region. Locally sourced seed will have a better chance of germination and survival because they will be from genetic stock that has adapted to local conditions. Eco-sourcing in this way also helps to maintain a record of what is and isn’t naturally native in the area.

Certain species, such as native beech trees, will only produce large quantities of viable seed during a mast year, which may only occur every 3 - 5 years. Other species, such as mānuka, have seed that is much more readily available. Below are guidelines on how to collect, process and store from five native forest species endemic to the Wakatipu Basin. Other species may also be suitable.

Landowner permission is required before accessing any property to collect seed. In the case of land administered by the Department of Conservation or Queenstown Lake District Council (any public land), a seed collection permit will be required, and this may take several months to obtain, so it’s best to apply early so that the opportunity for collecting seed is not missed.

Equipment needed

Large tarpaulin
Garden bags
Shepherds crook
Insect spray

¼” garden sieve
Fingernail clippers
Tweezers
Brown paper bags

Various sized sieves and bowls
Damp Rid or silica gel
Large trays
Stick blender (optional)

Mountain Beech

Mountain Beech

Mountain beech trees (Fuscospora cliffortioides) in the Wakatipu basin will typically produce seed sometime between February and April each year. The amount of viable seed available during a mast year is far greater than during a non-mast year. If the mountain beech trees are covered in a proliferation of small red flowers over summer this can be an indication that the trees will produce seed in autumn, provided that the flowers are pollinated. 

Timing is key with mountain beech as there is only a 2 – 4 week window of opportunity when the seed is mature and ready to fall. If you try to collect seed too early when it’s still green, then you won’t be able to shake it off the tree. If you leave it too late, then the seed will have already fallen onto the ground. Timing of seed maturation can vary hugely between different trees and between different areas of the basin, so it’s a good idea to find trees bearing seed early in the season and then keep an eye on them to see when they look like they’re ready to fall. Generally speaking, seeds on trees at lower altitude and in warmer, sunnier areas tend to mature earlier.

The seeds look a little like small bran-flakes. They’re ready to fall when they change colour from green to brown and the pods open a little so that the three seeds per pod can easily fall out (1 x flat seed and 2 x finned seeds per pod).  Before collecting the seed, it is advisable to do a check to see if it is viable.  Hold a seed with tweezers and use fingernail cutters to cut through the seed to see if there is a white kernel within.  Repeat this test with at least three flat seeds and three finned seeds. If there is no white kernel, then the tree is producing non-viable seed and it is not worth collecting.

The key is to find trees with seed-laden branches that are easy to reach.  The best access is often along the edge of a forest, either along the end of a fenced-off paddock, the edge of a lake or river, or natural grove.  Branches within the forest will typically be too high to reach. Hold or place a tarpaulin under as many branches as you can, then use a shepherd’s crook or another long implement, such as an extendable brush, to shake the branches vigorously. If the timing is right, then the seed should fall easily from the branches onto the tarpaulin.  Another option is to take hold of individual branches without removing them from the tree, place them gently into a garden bag, then shake the branch in the bag so that the seed falls off into the bag.

Shaking Beech Seeds into tarp

Shaking beech seed onto a tarpaulin (left) and into a garden bag (right)

Be careful not to mistake beech seeds for galls.  Galls are created when mites lay their eggs inside the tree’s leaves.  When they hatch, the larvae secrete chemicals that cause the leaf buds to form a protective ‘bubble’ around them.  This results in a bulbous gall that people can mistake for seed pods, although galls are much bigger than seed pods.

Mountain seeds and galls

Beech seeds (left) and galls (right)

NOTE: It is important to collect seed from multiple trees rather than just one tree.  This will ensure greater genetic diversity and, therefore, greater resilience of the trees that are grown from this seed.

Sieve the collected beech seed using a ¼” garden sieve to remove larger twigs and leaves.  Place a large tray (a lid from a plastic storage box will do) under the sieve to catch the seeds as they fall through. It is likely that a lot of pod cases and smaller leaves will be collected too but removing these from the mixture is very labour-intensive without specialised equipment.

Before removing the seed from the field, place into paper bags and label the bags with:

  • Species
  • Location
  • Date
  • Collector’s name
  • Any other notes

Before sealing the bag, spray some general insect spray into the bag. It is important to kill any insects otherwise they may feed on the seed in the bag.

Before storing the seed, it is important to first gently dry it out. Spread the seed out on a large tray in a sunny spot but avoid over-heating the seed. Anything above 15 degrees C for a prolonged period will cause the seed to age. It is important to remove adequate moisture from the seed mix so that it does not start to rot in storage. Beech seed is best stored in brown paper bags in a cool, dry place (between 5 and 15 degrees C). Placing a Damp Rid or packets of silica gel in with the seed can help soak up any extra moisture. Storing the seed in paper bags is preferable to storing it in plastic bags to help with allowing excess moisture to escape.

Sieving and drying beech seed

Sieving the seed mix (left), and drying the seed mix prior to storage (right)

Determining the number of seeds collected can be done using accurate digital kitchen scales.  Weigh the total volume of seed mix. Then weigh out 5 grams and count how many seeds there are in that quantity of seed mix. Repeat this at least three times and take the average. This number can then be used to calculate how many seeds there are in the total volume of seed mix collected. Test the viability of the seeds collected at the same time using the method described above.

Critical Success Factors

Coprosma propinqua

Coprosma species produce berries of various colours and the berries are usually ready between February and April.  When the berries are ready, they will fall off easily with little shaking. The quantity of seed varies greatly per plant. Note that coprosma species also follow general mast cycles in terms of abundance, but some plants will produce seed each year.

To collect berries, place the branches into a garden bag and shake vigorously so that the berries fall off into the bag. For larger plants with a greater abundance of berries, place or hold a tarpaulin under the branches and shake the berries onto the tarpaulin. Place the collected berries into paper bags for transportation offsite and label the bags with:

  • Species
  • Location
  • Date
  • Collector’s name
  • Any other notes

NOTE: It is important to collect berries from multiple trees rather than just one tree. This will ensure greater genetic diversity and, therefore, greater resilience of the trees that are grown from the seed.

Ripe Coprosma propinqua berries

Ripe Coprosma propinqua berries

Collecting Coprosma propinqua berries

Collecting Coprosma propinqua berries using garden bags and tarpaulins

Within each berry is two seeds and it is necessary to remove the flesh of the berry from the seed prior to storage. If the flesh is left on, then it may cause the seed within to rot. Also, if the flesh dries on the seeds and goes hard then it’ll take longer for the seeds to germinate. To remove the flesh, use a kitchen sieve and your knuckles or the base of a jar over a sink of water to rub the flesh off the seeds. Flush the material around in a large bowl to separate the seeds from the removed flesh. The seeds will drop to the bottom and so it should be possible to decant off the dirty, flesh-laden water. 

Another method that can be used to remove the flesh is placing berries in a large jug that is half filled with water and very gently stirring the mixture up with a stick blender. Be careful not to go too hard with the blender so as to avoid damage to the seeds and do not be tempted to do something similar with a food processor or Magic Bullet as this will likely be too rigorous for the seeds. Again, the seeds will drop to the bottom of the jug and so it should be possible to decant off the dirty, flesh-laden water. Use a sieve or colander to drain the excess water from the seeds and then lay the seeds out on newspaper to dry out further. These seeds must be thoroughly dried prior to storage to prevent the seed from rotting.

Cleaned coprosma seed is best stored in brown paper bags in a cool, dry place (between 5 and 15 degrees C). Placing a Damp Rid or packets of silica gel in with the seeds can help soak up any extra moisture. Storing the seed in paper bags is preferable to storing it in plastic bags to help with moisture regulation by allowing excess moisture to escape.

Cleaned Coprosma propinqua seed at various stages of drying

Cleaned Coprosma propinqua seed at various stages of drying

Determining the number of seeds collected can be done using accurate digital kitchen scales.  Weigh the total volume of seed, then weigh out 5 grams and count how many seeds there are in 5 grams. Repeat this at least three times and take the average. This number can then be used to calculate how many seeds were collected.

Critical Success Factors

Pittosporum

Seed on pittosporum trees (specifically Pittosporum tenuifolium aka Black Matipo) in the Wakatipu Basin will typically be available for collection sometime between April and September each year.  The seed is formed in a hard pod and when it’s ready, the pod will split open. The seed does not instantly fall to the ground, rather it remains stuck in the pod in a sticky yellow or black coating. This means that the ripe pods are available for picking over several months.

To gather the seed, simply place a garden bag on the ground and pick off each open pod individually and throw it into the garden bag. Place the pods into paper bags for transportation offsite and label the bags with:

  • Species
  • Location
  • Date
  • Collector’s name
  • Any other notes

NOTE: It is important to collect seed from multiple trees rather than just one tree. This will ensure greater genetic diversity and, therefore, greater resilience of the trees that are grown from this seed.

It is important to dry any excess moisture from the pods before handling and storing. This can be done by placing the pods in a tray in a sunny spot for a week or so.

Open pods ready for picking

Open pods ready for picking

Removing the seeds from the pods can be incredibly tricky given the sticky black coating on the seeds. Rolling the pods in fine sand can help to break up this coating and make it easier to remove the seeds from the pods, but it is still incredibly time-consuming.

Seed is best stored in brown paper bags in a cool, dry place (between 5 and 15 degrees C). Placing a Damp Rid or packets of silica gel in with the seed can help to soak up any extra moisture. Storing the seed in paper bags is preferable to storing it in plastic bags to help with moisture regulation by allowing excess moisture to escape.

Determining the number of seeds can be done using accurate digital kitchen scales. Weigh the total volume of seeds collected. Then weigh out 5 grams of seeds and count how many seeds there are in 5 grams. Repeat this at least three times and take the average. This number can then be used to calculate the total number of seeds collected.

Rolling seeds in sand

Rolling the pods in sand (left) and separated seeds covered in sand (right)

Broadleaf

Broadleaf

Berries on broadleaf trees (Griselinia littoralis) grow in bunches and are ripe for picking usually in April/May. When the berries are ready they turn from green to black in colour and are usually available for picking for a couple of months. 

To the collect berries, place a garden bag on the ground, pick off individual bunches of berries and throw them into the garden bag. Place the collected bunches of berries into paper bags for transportation offsite and label the bags with:

  • Species
  • Location
  • Date
  • Collector’s name
  • Any other notes

NOTE: It is important to collect berries from multiple trees rather than just one tree.  This will ensure greater genetic diversity and, therefore, greater resilience of the trees that are grown from the seed.

Rolling seeds in sand

Ripe and unripe broadleaf berries (left) and picking ripe berries (right)

Within each berry is one seed and if the seed is not being sown fresh, then it is necessary to remove the flesh of the berry from the seed prior to storage. If the flesh is left on and dries, then it’ll take a lot longer for the seed to germinate. To remove the flesh, use a kitchen sieve and your knuckles or the base of a jar over a sink of water to rub the flesh from each berry. A grooved rubber mat attached to a board can also be used. The berries need to be scrubbed until the thin flesh layer is removed from each seed. Flush the material around in a large bowl to separate the seeds from the removed flesh. The seeds will drop to the bottom and so it should be possible to decant off the dirty, flesh-laden water. 

NOTE: Broadleaf seeds are recalcitrant, which means that they do not survive drying and freezing, and so they cannot be dried out and cannot be stored for long periods. 

Once the flesh has been removed from the seeds, place the seeds in a Tupperware container with a damp layer of damp kitchen towel to prevent the seeds from drying out fully. Conversely, if the seeds are stored in conditions that are too damp for too long then they may begin to rot, which makes it difficult to store broadleaf seeds in perfect conditions. Ideally, these seeds would be sown soon after collection and processing to avoid errors associated with imperfect storage conditions.

Critical Success Factors

Mānuka and Kānuka

Mānuka (Leptospermum scoparium) and kānuka (Kunzea serotina or Kunzea robusta) seeds are relatively easy and simple to collect and process. New seeds pods are ready for collection from April/May.  These pods tend to remain on the trees for over a year, which provides ample opportunity for collection, although viability may decrease over time.

To the collect pods, simply find branches that are laden with pods and remove those branches from the tree using garden snippers. Be careful not to remove too many branches from each tree to avoid damaging each tree too much. 

NOTE: It is important to collect pods from multiple trees rather than just one tree. This will ensure greater genetic diversity and, therefore, greater resilience of the trees that are grown from the seed.

Rolling seeds in sand

Harvesting seed pod-laden branches from mānuka trees

Sometimes mānuka trees can present with a black, sooty coating known as ‘sooty mould’. This is simply a black fungus that feeds on the honeydew produced by insects. It is a good idea to avoid collecting this, but it may be impossible to collect much mānuka seed without collecting some sooty mould too. 

Place the cut branches into garden bags, take offsite and place into large, plastic storage containers in a warm, dry, sunny location. As the pods dry out, they release thousands of tiny seeds that resemble strands of saffron. These seeds are collected in the bottom of the plastic storage container. A gentle shake of the branches can aid with the release of the seeds. Mānuka seeds are reddish in colour, whereas kānuka seeds tend to be duller in colour.

Gather the seed from the bottom of the plastic storage container, sieve through a fine sieve to remove larger leaf matter, and make sure the seed is dry prior to storage.  To store, place the seed into paper bags and label the bags with:

  • Species
  • Location
  • Date
  • Collector’s name
  • Any other notes

Rolling seeds in sand

Mānuka seed pods (left) and mānuka seed collected in bottom of container (right)

It is not possible to count the number of seeds collected, but it’s reasonable to assume around 1,000 seeds per gram.