Chinese Elm Bonsai Tree Seeds (Ulmus Parvifolia)

The Chinese Elm or Lacebark Elm (Ulmus Parvifolia) is a deciduous tree native to Japan, China and Korea.  The tree is commonly used for urban planting throughout the United States.  The tree has small green leaves during the growing season that turn yellow/brown in the fall prior to shedding the leaves for the winter.

USDA Zone: 5-9
Germinating Difficulty: Moderately Easy

This tree grows moderately quickly at 12" - 36" per year once established in the ground, slower in a pot.  The seeds are fairly easy to germinate and will require a 24 hour water soak followed by cold stratification of 90 days.  This basically means you need to soak them for 24 hours then discard any seeds that float and drain off the water.  Place the damp (not moist) seeds in the fridge with a mildly damp paper towel, damp vermiculite or sand.  Be sure the moisture is minimal as excessive moisture will encourage fungal growth.  The bag of seeds should be placed in a refrigerator for about 3 months, ideally timed to end in early spring so the young trees can be moved outdoors as they grow.  The bag should be checked a few times a month to be sure the damping material did not dry out and that there are no seeds germinating early.  If a seed sprouts, remove it and sow immediately.  After the cold stratification, the seeds should be moved to a seed starting medium such as pearlite, planted about 1/16" deep and the soil tamped after sowing.  The soil must be kept damp, not soaked and warm for the seeds to germinate.  Some people use a fungicide treatment prior to cold stratification.  If kept too wet during stratification or after sowed, the seeds will rot.

My process for this in Pennsylvania is to soak the seeds for 24 hours and drain off any water. I then either put them in Tupperware outside under a bench with some sort of damping material or I sow them in seed trays, cover with hardware cloth (to prevent birds and rodents from taking them) then put them under a bench outside.  With both methods I time them to be outside from November until early March,.  Both of these methods require you to check them to be sure the soil or damping material stays damp.  You should also check the Tupperware for early sprouts and sow out when necessary.  

There are other ways to accomplish the stratification period, just search Chinese Elm Germination on Google, there is plenty of information.

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.