It is common to grow seeds for bonsai and find that they do not grow. This can often be a mistake on your part, but not always.
While there is no guaranteed way to make seeds grow, there are plenty of things you can do to increase your chances of success and there are some things you can try if the seed you have are just not doing anything.
Bonsai Seeds Are Just Normal Seeds
Before we go any further I need to make sure we are all aware that there is no such thing has “bonsai seeds” they are just normal tree seeds, they are not special seeds only for bonsai.
You just have to treat them in the same way as if you where trying to grow a full size species. The bonsai stuff comes after they are growing.
Bonsai is just the techniques that we apply to a tree to keep it small and stop it from becoming full size.
The fact that there is no special “bonsai seeds” means that’s there is no one way to do things, each tree species is going to be slightly different.
Check The Proper Germination Guide For The Tree Species
It doesn’t matter if you have already planted your seeds or not, you should still check the proper way things should be done.
If you haven’t done anything yet, then you can of course follow the guide and do things correctly from the start.
If you have already started trying to grow your seeds, you can check to see if you did things right. If you haven’t, that’s fine, you can wait and see what happens and then try and correct things if what you did hasn’t worked.
Why You Need To Know the Proper Process
Basically every tree is different and they will need a slightly different environment and conditions to grow.
Some seeds will need scarification, which is when you need to scratch the hard outer shell to allow moisture to get inside. Usually this happens in nature by its self, the seed will get blown around the ground and bang into things causing the shell to get scratched, but if you are growing the seeds then you will need to do it for them.
Most commonly, tree species we use for bonsai will probably need stratification. This is basically a cold spell before they will grow.
If you think about nature it makes sense. Trees produce fruit in autumn, but the seeds inside do not start growing until the following spring. They need to go through the winter before they grow.
No tree would want to start growing straight away as the cold winter would just wipe out the new seedlings.
Some species may need a longer time in the cold conditions compared to others, which is why it’s important to check what your species requires so you can give them the proper length.
Using the fridge is how we give our seeds this cold period. Of course we can leave them outside and let nature do its thing, but using the fridge gives us more control and the freedom to start the seeds anytime we want.
You may also find that seed instructions say things like “3-6 weeks of refrigeration” for example. If you see this, always go for the longer period.
I know it’s annoying, but it’s always better to give them more time, then you can be certain they have had long enough in the cold and more likely to successfully germinate.
When you take them out of the fridge, the sudden rise in temperature makes the seeds think it’s spring, so they start to grow.
If Your Seeds Don’t Grow
If you have followed the instructions for your species and nothing has happened, then there are two things that might be happening. You either need to wait a bit more, or your seeds are not viable.
Your Seeds May Not Be Viable
If a seed is viable it means it can grow.
If it’s not, it means it’s basically old and dead and they will never grow.
This is nothing you did, it just happens. Some seeds where just never going to grow or they just sort of become “out of date”.
If you have a handful of seeds, there will always be a small percentage that do not grow or fail in some way.
This is why when you plant any seeds you usually plant a large number, not just one individual seed.
Your Seeds Just Need More Time
You can’t really tell if your seeds are viable or not, so you may as well just wait and see what happens.
If you have followed the instructions and nothing has happened, just keep caring for them. Keep them damp (not wet, as this can cause mould to form or rot the seeds and kill them) and wait, they may start growing.
(You can read more information about What To Do About Mould On Seedlings (When Growing Bonsai)
Repeat The Instructions Again
If nothing has happened after a couple of months, then you should try and repeat the original instructions again.
Usually when you plant seeds (after they have had their cold spell) it should take a couple of weeks, maybe a month maximum to see some signs of growth.
If you didn’t follow the proper instructions for your species, then you can do this now.
If you did follow the instructions properly, well you can still try again, sometimes seeds need more time to get them to grow.
However, really you can only give your seeds more stratification or scarification. If the original instruction said to just plant them, there is not much more you can do. You can try a stratification period, but it may not work, but it may not.
At this point you have nothing to lose, so you should just try it. .
This is slightly harder to do since at this point your seeds are usually planted. If your seeds do not require scarification, then don’t do this to them, you will probably damage the seed. Only certain species need this.
If you did this originally as your species needs this technique, then I would NOT repeat this step. You have already done this, doing it again could damage the seeds.
If you didn’t scarify your seeds, and you have since found out that you should have done this with your species of seed, then you can either do two things:
Try and fish the seeds out of the soil and try to scratch them. This is of course messy and not ideal, but it will help.
Or you can also just leave them and hope that after a while the hard outer shell is broken down by the water. This may take a few years, by which point the seed may not be viable, so it’s also not ideal either.
I would probably fish them out myself. If you don’t scarify them, the chances of them growing are extremely low, so for me, it is worth the effort to try.
If your seeds are suggested to have a cold period, and they are not growing after the first attempt, I would repeat this step.
I would place your seeds and its pot (I’m guessing at this point you have planted them) into a zip lock bag and place them into the fridge again.
I would just follow the original instructions suggested time period. If it says “3-6 weeks” … go for 6. Throughout this time I would check on the seeds to make sure they are always damp.
Then after the suggested time, pull them out and hopefully this second “winter” can activate them to grow.
If you have planted your seeds outside then just leave them. You may notice that after the second winter they will germinate.
You often find people give up on their seeds and just reuse the soil, with the seeds still in there. Then a year later they find the seeds they give up on start growing.
If you have started some seeds for bonsai and they don’t seem to be growing, just be patient and hopefully they will grow soon.
If not, you can try the techniques again. This usually gets them to grow. If they don’t, then it means they were not viable and there is not much you can. In this instance the best thing to do is get some new seeds and start again.
I know that is frustrating, but growing seeds is a numbers game, the more you do, the more likely you will have success, especially for some species, which have a higher fail rate than success.
Once you get Your seeds to germinate you should read – Starting A Bonsai From Seed – A Guide for Years 1 To 5