Japanese Black Pine Bonsai Tree Seeds (Pinus Thunbergii) Kuromatsu

The Japanese Black Pine (Pinus Thunbergii), also known as Kuromatsu in Japan is a staple of bonsai throughout the world.  The JBP is a two needle, two flush pine.  Once understood, the decandling process can produce reasonable small needles and ramification fairly quickly.

USDA Zone: 6-8
Germinating Difficulty: Easy

This tree grows at a moderate rate at 12" - 18" per year in a pot (could be up to 4' and down to a few inches).  The seeds are easy to germinate.  They will require a 24 hour water soak, starting out as warm/hot water.  Seeds that float should be discarded after the 24 hours and the water drained.  The remaining seeds should be planted in a seed starting medium such as pearlite, planted about 1/8" deep and the soil tamped after sowing.  The soil MUST be kept damp (never dry and not often soaked) and warm for the seeds to germinate which usually happens in 10 - 20 days.  A seed germination heat mat will help improve germination.

Seeds should be used as soon as possible.  Seeds that will not be used immediately should be stored dry in the plastic bag in the refrigerator.  The quality of the seeds will degrade over time, normally 3-5 years.

Seeds are sourced from the most reputable commercial seed sources.  These are the same seeds we use to start our bonsai.