Stratification is the process of subjecting seeds to cold in order to snap them through their dormancy.

Lots of tree seeds are genetically programmed to survive through a winter and then when spring comes they sense the change and sprout into seedlings. With some tree seeds they will never sprout until they feel that cold and warm cycle. So we artificially create that cycle thus breaking their dormancy.

I have a chart of the common bonsai seeds and how to germinate them right here

I also have a video tutorial at the bottom of this page.

Ok! Here is a pair of seedlings that have gone through the process of scarification and stratification. I will show you how to get a successfull sprouting of your tree seeds for bonsai. Just like this!

The Challenge of Tree Seeds

One of the big things about tree seeds is that they are perfectly tuned to the environment that they have been grown in for generations. Good thing and a bad thing! For example, if you are going to grow trees that live in a climate that has a winter then then tree and the seeds are programmed to live through this cold period. They go dormant. And they need to go dormant or they probably will not sprout. This means that you have to create an artificial cold season for the seed. And we can do this with a refrigerator!

So Here is the typical process

And this can vary from seed to seed type but this is the typical process.

Step 1: Soak the seed in water to soften up the hard shell that surrounds it.

Step 2: Plant the seed in some kind of soft bedding like peat moss

Step 3: add water and place in sealed plastic bag

Step 4: Place in refrigerator for period of time (Simulates artificial winter)

Step 4: Remove and plant in soil (Simulates spring)

Let's Do it!

Step 1: Scarification - Soak the seeds in room temperature water for a period of time. This is usually between 24 and 48 hours. This softens up the shell so the seed can break through. Remove any seeds that float. They are probably empty shells and are not usually viable for germination.

Note about scarification: Some seeds have very hard shells and it is sometimes recommened to actually scratch the shell with a needle or pin to further help its breakdown. Your particular seed will come with instructions for this.

Step 2: Placing in a soft mixture - Remove the floating seeds. You can dispose of them. They are most likely unviable as seedlings, often simply empty husks. Plant the sinking seeds in peat moss.

This seed pod was a floater. See how it is just an empty husk? No seed in there!

Step 3: Bag it! Water the peat moss so it is moist but not wet. Then place it all in a sealable plastic bag.

Step 4: Into the Fridge! Ok, now put them into the refrigerator to simulate the cold season. This length of time can vary from a month to six months. I have a chart for more of the common seeds here.

Check on them regularly. If any have sprouted you can take them out and plant them right away!

Step 5: Plant them! Do this to the recommended depth and with the recommended soil. You can see in this picture that I also do this process with floaters sometimes. But the germination rate is pretty low with them.

I have lots of seeds planted in a small hot house. It helps a lot! Good luck with your seeds.

Tips and More

Label absolutely everything with the pertinent information. And label at every step of the process. I even wrote how many seeds are planted in each little chamber here. If they are going to be in the fridge for a month or more you don't want to forget what they are or what day they went in! So, particularly label those plastic bags with the date.

» Plant lots of seeds. You don't know how many will actually germinate so it is a numbers game. Plant lots of them. You can always cull away the weaker ones if you end up with too many seedlings.

» Check your specific type of seed and follow the recommendations for it! I have a chart of the more common seeds here.

» Check on the plants regularly, particularly while in the fridge. If some have sprouted take them out and plant them!

» Make sure you label everything and at every step of the process. Particularly put the dates. After 30 or 60 days in the fridge it is easy to forget when you put them in there!

Tamarind Tree 10 Seeds/Seed -Bonsai- Tamarindus indica

• Mature Height: 80'
• Known for its tart pulp used in chutney and numerous other dishes
• Very attractive tree, especially when young - makes a terrific indoor tree that may easily be kept short
• Makes an excellent bonsai!
• 10 Seeds

Japanese Pagoda Tree 10 Seeds - Sophora - Bonsai

Super Sprouter Propagation Station w/ 7" Dome

This is the heated greenhouse that I use.

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