True double flush pines are the Japanese Black Pine, Japanese Red Pine, American Pitch Pine, Yellow Pine (Shortleave Pine), the Loblolly Pine and the Aleppo Pine. They all grow in somewhat humid warm climates (with the exception of the Aleppo Pine, which grows in the desert in many areas), meaning that they have long growing seasons, enabling them to have that second flush of growth.
The natural reason why those pines have a second flush is that they are living in conditions where they have to withstand against the hard weather conditions and hasards such as strong storms along coast lines where black and red pines reside, or the bush fires the pitch pines have to face in contradition to the colder high elevation grounds and the much shorter growing season, where the single flush pines reside.
Development Phases of Double Flush Pines
0-2 years: seedlings
2-4 years: stem thickening and bud development
4-6 years: branch development.
+6 years: moving from early development to middle development
Once the desired trunk thickness and height, together with wel developed tertiary branching have been established, one can say that the tree is entering advanced development or even the refinement stage. This can be achieved as early as in sixth years, starting from seed under optimal growing conditions. A summary video about this achievement can be watched here on YouTube, showing proof of creating a world class Japanese Black Pine shohin bonsai, where the thread on the bonsainut.com forum illustrates the progress of each development step year by year with pictures and detailed clarification.
Seasonal Care of Double Flush Pines
Repotting
The best time for repotting double flush pines is indicated by the swelling and change in coloration of its buds to a somewhat greenish color in early spring.
At repotting time, remove between 30 and 60% of the old soil that sits between the roots, but leave the center of the root ball, the shin (pronounced as "shien") preferably untouched. To do that, use a chop stick or similar to remove the soil without damaging the roots. Then remove the surplus roots with scissors or other cutting tools.
Be careful with root pruning. Do not remove more than a third (up to maximal 40%) of your roots to ensure that the tree still has the strength to respond well to the (recommended) bud cutting later in spring.
- Younger pines can bear with 30% up to maximally 40% of root pruning.
- Older trees however should get a reduced conservative root pruning of 20 to 30% max.
The recommended soil mix is 1 part akadama 1 part pumice 1 part lava rock and 1 part river sand or kiryu. If you live in dryer or windy regions with low rainfall, you can double the amount of akadame and pumice.
Trees in early development will do perfectly with a much heavier standard potting mix, which allows to gain growth in a shorter time.
Spring
For both young bonsai pines as well as for trees in the refinement stage, you can start with heavy fertilizing in early spring (as opposed to the more moderate fertilising of Juniper bonsai). Particularly for pines, this is good a practice to prepare them for the first candle pruning in the summer, so they are in optimal health to produce new buds.
Fertilising
For young pines that need high nitrogen to support their strong growth in a very short amount of time, an NPK norm of 15-8-6 or equivalent is recommended as a reference.
In Belgium & The Netherlands Substral Osmocote with NPK 22-7-14 comes in handy (available as blue packaging "for roses" or as "universal" and "for conifers and hedges" packaging, they are all the same) Watch out, the yellow packaging Substral "Naturen, for Buxus, Hedges & Conifers" only has an NPK of 6-3-5 (!).
Personal notes: NPK Norm: Max 15-8-6 N= not under 6 We use liquid AND granular (it takes 30 days until they start releasing) PAUZE 2-3 weeks minimum.
miracle gro 24-8-16 = kick - super thrive = hormones - osmocote plus = 15-9-12
As from mid stage development, where you focus on secondary and tertiary branching and ramification, switching to organic feeding is the way to go. Biogold with NPK around 5-6-3 is the reference, but do keep in mind that not one Japanese bonsai grower would use such an expensive product.
No Pruning & No Wiring in Spring Time
No pruning and no wiring in spring time is the oneliner to keep in mind. So... don't.
This article will be built up as I grow experience and gather context from what I can find on the internet as valuable information, that has been confirmed by trustworthy sources. Thank you for bearing with me while I do just that.
Comments