Picking and potting notes

These are notes on how you can collect seeds, store them, prepare them for potting, and then pot them.

They may be useful for you for in your garden or restoration project.

Collecting seeds

When you collect your own seeds check the biosecurity of the source.  The seeds should be from the local bush area, not the seeds from a plant that came from a garden centre, or bush elsewhere.  Take seeds from plants which look typical of the bush, not odd plants from the bush fringes which could have come from local gardens and actually be hybrids.  Take with you photos or drawings of the plants and trees you are wanting for accurate identification.  Some plants growing in the bush, such as lancewood, are actually hybrids and should not be propogated.  Make sure you get a "true" seed.  This is known as "eco-sourcing".

It is important to record the name of the seeds and the place and date you collected them.  This information needs to stay with each batch of seeds, all the way to the point where the seedlings go into the ground.  Then you have all the information you need to successfully repeat the exercise.

Small dry seeds such as manuka, kanuka and rata can be collected by taking a branch with seed heads about to seed.  You may have to return several times to the tree before the time is right to collect them.

Storing seeds

Some fleshy seeds, for instance Tawa, need to be soaked in water for two to three days.  After that, the flesh can be washed off, in a drainer for example, using a water hose.  The seeds should then be spread out in a warm place to dry.  This prevents any fungal problems, and stops them from starting to sprout immediately.

Seed heads should be put in an open plastic supermarket bag and hung it in a dry place.  Several weeks later, you can shake the seeds into the bottom of the plastic bag and remove the branch.

Store seeds in dry cool conditions (like in the bottom of the fridge) if not needed immediately.  Seeds including Kahikatia, Kanuka, Karaka, Karamu, Karo, Kawakawa, Kohekohe, Lemonwood, Manuka, Matai, Miro, Ngaio, Poroporo, Tawa and Totara, need cold treatment to stimulate germination.

Stratification (cold treatment): After soaking the seeds in water for 12-24 hours, mix them with a moisture retaining medium such as sand, peat or well-rotted sawdust.  The mixture of seeds and medium is placed in a container or jar in a fridge for 2-5 weeks.  Don't forget to label the containers.

Sowing seeds

Potting-on

Potting-on into cardboard milk containers

For best results you will need to use good potting mixtures.  Potting mix specifically developed for native trees can be bought from nurseries.

Big seeds should be sown in a cardboard milk carton filled with potting mix.  Punch some drainage holes in the bottom of the carton, then cut or fold down the top to approximately 10-15 cm high, then add the potting mix, and finally push in the seed.  Cardboard milk cartons are preferable because seedlings grown in these can be planted directly into the ground without first removing the "pot", as the milk carton will rot away in the ground.

Smaller seeds should be sown in a seedling tray or an ice cream container with holes in the bottom for drainage.  Label the containers with contents, where the seeds came from, and the date sown.  If you cover the container with plastic wrap, you need to water them only every three days or so.  Putting insulation material such as polysterene or thick newspaper underneath will keep them warmer.  Putting "bubble-wrap" over the top works too!  Place the containers in indirect light, as direct sunlight dries out the soil.  Seeds don't show themselves if the soil is constantly changing between wet and dry.  They want constant warmth and damp.

Some seeds take a long time to germinate, so keep watering and checking them even if nothing happens for weeks.  Make a note of how long it takes each type of seed to germinate for future reference.  Once seedlings have reached about 2 cm or have 2-4 leaves, they should be transplanted into milk cartons.

Your tree seedlings need TLC for about 2 years before they can be planted out in your garden or restoration area.