Propagation of Kahikatea
by Wayne Bennett www.forestflora.co.nz
Kahikatea seeds. Photo by Forest Flora
Seed collection
The seeds of kahikatea are produced on the female trees in the autumn. Half of the population are males which contribute pollen in the spring. Like all members of the podocarp family, the seeds sit on a sweet, colourful, fleshy, "foot". In the case of kahikatea this is bright orange when ripe and the seed is dark with a waxy bloom like a dark grape has. The seeds can be picked directly off the tree or from the ground beneath. It is good practice to collect seeds from a number of trees if possible.
Ecosourcing
All native plants vary genetically across the country, Growing the plants from your location will help protect the genes found there. Growing native plants and planting them in new locations is slowly eroding this regional distinctiveness. As a rule of thumb it is good to emulate natural dispersal as closely as practical.
Sowing seed
Prepare a suitable sized tray for the seed you want to sow.( an icecream container will support up to 100 seedlings).
Make sure that there are drain holes in the bottom. Half fill with fresh seed raising mix (never potting mix or soil) and press the surface firm and flat. Sprinkle seeds over the surface, press in with a small board and cover to a depth of about 4 mm. Soak the tray thoroughly, label with the date, species and location seed was collected from. Cover with glass or plastic and place in a shady position. At normal temperatures, seed sown in the autumn will usually begin to germinate in the spring.
Care of seed trays
Keeping the seed trays in a shady place will discourage weeds and the covering will help prevent drying out. It is important to look over the tray each week to check for weeds, drying out and of course for the first seedlings to emerge. Once the seedlings emerge (you can distinguish these from weeds because they are all the same) bring the tray out into a sunny position, remove the covering and water as often as necessary but avoid over watering.
There is very little nutrient in seed raising mix as this can build up and become harmful to tiny seedlings. As the seedlings grow they may need to be watered occasionally with a liquid feed to keep them healthy and growing well.
Pricking out
Once the seedlings are big enough to be handled they can be removed and placed in their first individual containers. This is called pricking out. Lift each seedling by
sliding a tool like a pencil or screwdriver under while holding by the leaves to avoid damage to the stem. Now the seedlings can be placed in regular potting mix
containing slow release fertiliser. Potting mix is much better than soil in containers because it both holds water well and drains well, so is well aerated.
However the fertiliser only lasts about nine months. A suitable sized container should be adequate for the seedling for the life of the potting mix, in this
case a 5cm pot or small yoghurt pot with drain holes is ideal. Water the seedling well after placing it in the container to settle the potting mix around the roots.
Potting up
In about nine months the small seedling will be large enough to move to a larger container. Seedlings should progress through a series of containers of increasing size as the potting mix is depleted of nutrients until it is large enough to plant out. At Forest Flora we prefer small trees in containers of around four litres which are around two metres tall. These are tall enough to have a good head start on weeds which will inevitably challenge them.
Planting out
Kahikatea tolerate significant frosts but don't cope well with drought until their roots are well established. If the site is unlikely t be flooded in winter, plant in late
autumn as soon as the ground is well wetted. Where there is a significant chance of flooding it may be better to wait until that possibility is reduced, perhaps
as late as September. Surrounding forest will give an indication of spacing, but around four to six metre spacing will eventually result in a closed
canopy. A whole book could we written on planting, but the most important thing is to be sure that the trees are very firm in the ground and get water until the
roots are established. Natural rain can usually be relied on for this if the planting is done at the right time.
Kahikatea, though dominant, are only one species in our local forest remnants. When combined with a healthy assortment of the other native plants of these areas the site becomes much more interesting and sustainable.
Thanks to Wayne Bennett from Forest Flora for writing this section and the use of the photos on this page. www.forestflora.co.nz
The seeds of kahikatea are produced on the female trees in the autumn. Half of the population are males which contribute pollen in the spring. Like all members of the podocarp family, the seeds sit on a sweet, colourful, fleshy, "foot". In the case of kahikatea this is bright orange when ripe and the seed is dark with a waxy bloom like a dark grape has. The seeds can be picked directly off the tree or from the ground beneath. It is good practice to collect seeds from a number of trees if possible.
Ecosourcing
All native plants vary genetically across the country, Growing the plants from your location will help protect the genes found there. Growing native plants and planting them in new locations is slowly eroding this regional distinctiveness. As a rule of thumb it is good to emulate natural dispersal as closely as practical.
Sowing seed
Prepare a suitable sized tray for the seed you want to sow.( an icecream container will support up to 100 seedlings).
Make sure that there are drain holes in the bottom. Half fill with fresh seed raising mix (never potting mix or soil) and press the surface firm and flat. Sprinkle seeds over the surface, press in with a small board and cover to a depth of about 4 mm. Soak the tray thoroughly, label with the date, species and location seed was collected from. Cover with glass or plastic and place in a shady position. At normal temperatures, seed sown in the autumn will usually begin to germinate in the spring.
Care of seed trays
Keeping the seed trays in a shady place will discourage weeds and the covering will help prevent drying out. It is important to look over the tray each week to check for weeds, drying out and of course for the first seedlings to emerge. Once the seedlings emerge (you can distinguish these from weeds because they are all the same) bring the tray out into a sunny position, remove the covering and water as often as necessary but avoid over watering.
There is very little nutrient in seed raising mix as this can build up and become harmful to tiny seedlings. As the seedlings grow they may need to be watered occasionally with a liquid feed to keep them healthy and growing well.
Pricking out
Once the seedlings are big enough to be handled they can be removed and placed in their first individual containers. This is called pricking out. Lift each seedling by
sliding a tool like a pencil or screwdriver under while holding by the leaves to avoid damage to the stem. Now the seedlings can be placed in regular potting mix
containing slow release fertiliser. Potting mix is much better than soil in containers because it both holds water well and drains well, so is well aerated.
However the fertiliser only lasts about nine months. A suitable sized container should be adequate for the seedling for the life of the potting mix, in this
case a 5cm pot or small yoghurt pot with drain holes is ideal. Water the seedling well after placing it in the container to settle the potting mix around the roots.
Potting up
In about nine months the small seedling will be large enough to move to a larger container. Seedlings should progress through a series of containers of increasing size as the potting mix is depleted of nutrients until it is large enough to plant out. At Forest Flora we prefer small trees in containers of around four litres which are around two metres tall. These are tall enough to have a good head start on weeds which will inevitably challenge them.
Planting out
Kahikatea tolerate significant frosts but don't cope well with drought until their roots are well established. If the site is unlikely t be flooded in winter, plant in late
autumn as soon as the ground is well wetted. Where there is a significant chance of flooding it may be better to wait until that possibility is reduced, perhaps
as late as September. Surrounding forest will give an indication of spacing, but around four to six metre spacing will eventually result in a closed
canopy. A whole book could we written on planting, but the most important thing is to be sure that the trees are very firm in the ground and get water until the
roots are established. Natural rain can usually be relied on for this if the planting is done at the right time.
Kahikatea, though dominant, are only one species in our local forest remnants. When combined with a healthy assortment of the other native plants of these areas the site becomes much more interesting and sustainable.
Thanks to Wayne Bennett from Forest Flora for writing this section and the use of the photos on this page. www.forestflora.co.nz