About once a week we get someone contacting us regarding bonsai seed kits. Usually, they have bought or received a bonsai tree seed kit as a gift. Once they’ve opened it and had a look at the info included, they have plenty of questions. Here is a page answering the commonly asked questions, along with some notes regarding bonsai seeds.

What are bonsai seeds?

A lot of bonsai enthusiasts are very dismissive of bonsai seed kits. I am too probably, depending on how good the kit is. The main problem I have with these kits is that many (not all) of them give them impression that all you need to do is plant a “bonsai seed” and it will grow into a perfect little bonsai. This is not correct. In reality, there is not such thing as a bonsai tree seed – it is merely the seeds from normal trees. If you plant them and get them to germinate, they’ll grow into normal trees and not into bonsai. The seedlings need training in order to turn them into bonsai trees.

The good thing about bonsai seed kits is that they give people a low cost way to get into the art of growing bonsai.

How do I get bonsai seeds to grow?

The beginning of the process of course is getting the tree seeds to germinate. Now that we know that we have tree seeds and not bonsai seeds, we begin to understand the process. Most of the seed kits talk about stratification – soaking the seeds in water, putting them in the fridge, rubbing the seeds with sandpaper, putting them on cotton wool. All these things are often mentioned.

The right time of year to germinate bonsai tree seeds

My experience of growing seeds is pretty straightforward.

  • I take a seed tray, the kind of black plastic tray that you find in garden centres.
  • Put compost (usually mixed with perlite for drainage and air flow) in the tray.
  • Water it to make sure that all of the compost is wet, allow the excess water to drain away.
  • Put the seeds onto the surface of the soil if they are very small, or push larger seeds (acorns for example) into the compost.
  • Sprinkle with a fine layer of compost
  • Cover the seed tray. You can buy clear plastic tops for this. Search for seed propagators online.
  • Then wait! You’ll need to keep the soil moist. A mist sprayer is really good for this, as watering cans may chug out too much water too quickly and move the seeds around in the tray.

I always start seeds off at the end of winter. Seeds generally expect to grow in spring. That’s natures plan. I find starting seeds off at this time of year gets rid of the need to do any of the stratification business. Think about this though – if the seeds are from exotic, tropical trees, where the seasons don’t work in the same way – how does this affect things? This is where horticultural knowledge starts to kick in. You need to know what kind of seeds you have and research how these species of trees grow. This is another common bugbear that bonsai enthusiasts have with bonsai tree seed kits. Some seed kits give you very little info on species.

What soil do bonsai trees seeds need?

We sell lots of different kind of bonsai soil. As bonsai growers, we use different kinds of materials to make a bonsai soil mix. This gives great results for our mature bonsai. For seeds however, this soil isn’t required. I tend to use compost and mix it will perlite. About 3 parts compost to 1 part perlite. I find that this works fine. This mix holds water but also drains well – roots need to breathe and can rot if constantly sat in water.

Where do I put my bonsai tree seeds?

Trees live outdoors. Only a very few species of trees will survive indoors. Even fewer will thrive indoors. Most of the seeds in bonsai kits need to live outdoors. If you’ve got your seed kit in front of you, have a look at what species of trees you have and search online for each one. For example, if you have Japanese Maple seeds, type in “Japanese Maple bonsai tree care information” or similar to bring up results. Good species guides discuss location.

You’ll probably find that most of your species need to live outdoors. Many seeds will germinate indoors, but once germinated, you’ll need to move the seedlings outside, into a protected location as they are quite fragile at this stage. A greenhouse or similar is great for this. I always germinate seeds in a greenhouse. If space doesn’t allow for a greenhouse, search “How to make a cold frame” for a low cost / small space solution.

What about winter? If you’ve started your tree seeds off in spring, the plants have late spring, summer and autumn to get established. By the time winter comes, the little seedling should get through winter fine, with a little protection – again the greenhouse / cold frame is perfect for this. REMEMBER – trees from warmer parts of the world can be more tender to the cold and can require more winter protection.

How long does it take for bonsai trees to grow?

Growing bonsai trees from seed is a lengthy process. It will take years to produce something that looks like a bonsai and probably a decade or more to produce something that has the wow factor. Nothing wrong with this – but do be aware of how long it will take.

  • Year 1 – get the seed to germinate.
  • Year 2 – grow on the seedling into a healthy little plant. Also a little work on the roots (see below)
  • Year 3 – bonsai training starts.


    St. Lucie Cherry seedlings. Pictured in the autumn of their second year. I probably should have separated them at the end of their first year but will definitely plant them into individual pots this winter. I could wire the trunks at this stage if I want to so that they have movement, now that the wood has lignified.
    St. Lucie Cherry seedlings. Pictured in the autumn of their second year. I probably should have separated them at the end of their first year but will definitely plant them into individual pots this winter. I could wire the trunks at this stage if I want to so that they have movement, now that the wood has lignified.

Pricking out and potting on

If you’ve planted your seeds in groups in a pot or seed tray, you’ll need to separate the seedlings into individual pots to give them space to grow. You’ll need to wait until the seeds are large enough to handle them without breaking them. This is probably at the end of year one or though it could be earlier than this. Search “Pricking out seedlings” for further information.

Bonsai styling of tree seeds

Okay, so your seedling are now established are healthy little trees. Now you can actually start doing bonsai stuff! Here is a bit of a list of things you might do.

Lightly prune the roots and spread them out

I would do this in Feb / March of year 2 or Feb / March of year 3 if the tree is still very small. Normally, trees send their roots downwards for anchorage and to find water. For Bonsai, we want our trees to have a root buttress – lots of visible roots on the surface of the soil. Do a search for “Root buttress” to see what I mean. Bonsai growers call this a Nebari. The fact that you can carefully move the delicate roots of seedings is one of the major benefits in starting bonsai trees off from seed – the roots are flexible enough at this time to move. With older trees, it is more difficult.

You can also lightly prune longer roots in order to encourage the tree to produce lots of smaller roots and not just long ones.

Wrap wire around the sapling

Bonsai trees tend to have curving movement and are generally not straight, although some are! The sapling is thin enough at this stage to wire the trunk. You would wrap wire around the trunk and gently bend it, so that it has a little movement. This can be done at any time of year. The wire needs to start on for around 6 months to a year. The tree will thicken as it grows, so don’t make the wire too tight and keep an eye on it to make sure that it doesn’t mark the trunk.

Prune the bonsai sapling back to encourage branches to grow.

Probably year 3. If you don’t prune the tree at all, it is going to grow straight upwards. Tree sapling at genetically programmed to do this, as in the wild, they would be in competition with other plants on the ground. For bonsai, we tend to want a nice canopy with little branches growing out sideways, as this creates the image of a large tree in our minds. The way to achieve this is to cut back the sapling, so that you encourage it to put out new growth where we want it.

Two more search terms for you “back budding” and “hard pruning”

Some trees respond better to pruning than others. Most deciduous trees back-bud really well. Lots of evergreens do not. Again, this is where horticultural knowledge kicks in. How well a species of tree back buds affects how you train it.

Planting the tree into a bonsai pot

At some point, you’ll want to plant the tree into an attractive bonsai pot. Newer bonsai people will want to do this quickly, more experienced growers may wait for years, or may well plant the trees into the ground / into larger tubs. Remember that when you keep the tree in a small pot, growth slows down. If you want thick trunks on your bonsai, this is done by allowing trees to grow for a number of years and then hard pruning the tree back, giving a thick trunk but on a small tree AND pruning the roots back, so that it will fit into a smaller pot.

Just remember that a stick in a pot will only ever look so good. There is nothing wrong with putting a sapling into a ceramic bonsai pot and that we’ve all done it. However if you want to make great bonsai from seeds, then growing them on first is really useful.

Other things to consider

You are going to want to fertilise your saplings to encourage lots of growth. I’m not going to cover this here.

Why start a few seeds off when you can start lots! Every time I have done a bonsai project, I always wish I had done more. Tree seeds are low cost so why not start a good number off.

Tree seedlings are fragile. In nature, it would be a numbers game with a mature tree producing hundreds or thousands of seeds per year. Seedlings will easily die if not kept watered.

Animals will eat your seeds! Squirrels keep nicking my acorns. Protect them.

Fungal infections can attack your seedling. Damp, warm soil is the perfect environment for fungal infections. Another search term for you is “Damping off seedlings.” Good air flow around your seedlings helps stop this, as does a fungicide spray, available from garden centres, DIY stores and online.

Conclusion

There we go! I think I’ve answered many of the questions that we get asked about how to grow bonsai trees from seed. If you have further questions, please feel free to contact me. Oh and don’t forget that we sell all the pots, tools, wire and some of the other bits you’ll need, along with lots of lovely bonsai trees that have already had all of the above done for you!