Every couple of months I buy a selection of trees seeds to train as Indoor and Outdoor Bonsai.
These tree seeds are not specifically Bonsai tree seeds but tree seeds that can be grown and eventually trained as Bonsai.

When I am selecting trees seeds to grow, I tend to select non-evasive species just in case some tree seeds get spread around by mistake. This is not a problem with Tropical Indoor trees as they would not survive in our temperate climate.

The new selection is a mixture of hardy outdoor and sub-tropical indoor trees.

One of my favourite trees and very common in Ireland is the European Larch (Larix decidua). This is a very easy tree to grow and train. Also selected is the Trident Maple, Japanese Privet, Dwarf Pomergranate, Korean Spruce and the impressive Jacaranda with its blue flowers.

Some tree seeds require different types of pre-treatment before you sow them. This can range from simple pre warm water treatment to a wash in petrol.

For instance the ‘European Larch’ would require 4 – 6 week cold stratification. (a brief stay in the fridge)

Take your tree seeds and pre-soak overnight in cool water. Then take a handfull of vermiculite, dip it in some water and then place in a zip-lock bag.
Get your tree seeds and place in the zip-lock bag. Give it a good shake before placing it in the fridge for up to six weeks.

Stratification helps to mimic the winter months and speeds up the germination process (also known as Forced Germination). Some seeds require a mixture of warm and cold treatments.

Other common treatments would be scarification, this involves cutting into the seed coating with a sharp knife or use sand paper to help break down the seed coat of the hard shelled seeds.

This months trees require:

Trident Maple — 12 weeks cold stratification
Japanese Privet — 14 weeks cold stratification
Dwarf Pomergranate — 14 weeks cold stratification
Korean Spruce  — 4-6 weeks cold stratification
Jacaranda mimosifolia — warm water soak prior to sowing followed by bottom heat at 16 – 18 degrees.

Storing Tree Seeds

Tree seeds are best sown fresh if possible. If you need to store them, then place them in a bag with little moisture in the vegetable section of your fridge. I tend to use small padded envelopes (fussy)

Sowing Your Seeds

The Outdoor trees can be sown in pots for the first number of years, this is dependent of course on the tree species and how fast it grows. The soil mixture I use is very light and free draining. A mixture of John Innes No 2 and horticultural sand.

For Indoor trees these require a similar soil type as above except I would use some bottom heat, either bench heating cables or if space is limited a propagation hobby kit.

If you have any questions on growing from seed, send me a comment or question.

This post was written by Paul Masterson

Paul is a collector of Bonsai, tropical plants and owner of Bonsai.ie.