How to grow a Bonsai tree from seed: Bonsai cultivation technique

Most Bonsai takes years to train before you call them finish so this is not the hobby for an impatient person. You’ll need patience to grow a Bonsai tree from seed.

It can take three to five years of care before your Bonsai tree gets big enough to start shaping. However, it’s worth it when you can see the fruits of your labor pay off and your Bonsai trees thrive.

Larger Bonsai can be trained from nursery stalk, but smaller Bonsai one hand or less can be easier to train from seedlings and seed stalk.

You may need to wait several months for your seed to germinate depending on the species, and some finicky and slow-growing tree species may also need several seasons just to break their seed coats.

A bonsai tree that is grown from a seed and properly cared for over the years can be beautifully shaped, uniquely styled, and passed down from one generation to another.

Select a tree and collect seed

You can choose the specific tree acccording your environment and climate. 

  • Indoor Bonsai Trees – Camellia, Ficus, Gardenia, Hawiian Umbrella, Kingsville Boxwood, Serissa etc.
  • Outdoor Bonsai Trees – Beech, Birch, Cedar, Cypress, Elm, Ginkgo, Juniper, Larch, Maple etc.

How to plant Bonsai seed

Conditions to grow a Bonsai

Importance of light to grow Bonsai from seed:

Every type of tree uses light and heat differently and thus has a unique and individual need that should dictate its position when being grown as a Bonsai.

A sycamore , for example needs a lot of light and therefore a sunny position to remain healthy. While a beech can only use small amounts of light and often thrives in the shade.

Importance of temperature to grow Bonsai from seed:

Temperature also plays an important role. When it is very warm, the plant tries to cool down through evaporation via the leaf pores.

As soon as the water reserves are exhausted, the leaf pores are closed to avoid losing any more, but when this happens photosynthesis stops because the oxygen needed for this is also absorbed through the leaf pores.

Since the amount of water in a Bonsai container is always limited there is usually no photosynthesis on hot days. On such days it is often sensible to move trees to an alternative shady place.

Importance of wind to grow Bonsai from seed:

The role of the wind should not be underestimated. On a balcony, for instance, it prevents the build-up of heat during lengthy sunny periods.

However, strong wind will dehydrate both the plant and the soil, so a compromise must be found between a corner out of the wind and a position in the open. The amount of wind particular species of tree can withstand is outlined under their individual descriptions.

Germination of seeds

how to grow a bonsai tree from seed

The ability of tree seeds to germinate depends on a number of factors: the quality of the seed, its origin, the season and manner of its collection and storage and finally, its ‘germination capacity’.

Some seeds have the additional complication of dormancy. This is nature’s way of protecting the seed during the winter so that it can awake from its sleep in the following spring ready to grow into a proper tree.

The best time to sow tree seeds is in spring. Fill an ordinary plastic seed tray with a 1:1 mix of peat and sand. medium grade sphagnum moss and washed sharp sand are ideal.

Alternatively, use a ready-mixed seed sowing compost. Fill the seed tray to half its depth with compost, press it down lightly and then sprinkle the seed evenly over the surface.

Next, cover the seed with a further sprinkling of compost to a depth of about two to three times the thickness of the seed. Thus, if the seed is 3 mm in diameter, cover the seeds to a depth of 6-9 mm.

Finally, sprinkle over the top of this a fine layer of sharp sand or grit to keep the seeds weighted down. Keep the compost moist at all times but never soaking wet.

A temperature of about 10-15*C is ideal for germination and this makes the environment of an ordinary kitchen a very suitable place in which to keep the seed trays.

If you have a cool or heated greenhouse so much the better. A heated propagator would of course be ideal. It is advisable to water the seeds with a solution of weak Bordeaux mixture or Cheshunt compound in order to prevent ‘damping off’.

At the right temperature the seeds should begin to sprout in about two to four weeks time. Leave the seedlings in the seed tray until the first pair of proper leaves develops.

Watering of Bonsai

Watering must be carried out with greater than usual care. The Bonsai container is much smaller than that of a normal pot plant, with the result that what water there is gets used up that much more quickly.

How to grow a Bonsai tree from seed

With trees that are well rooted the major part of the water is used by the plant itself.

Depending on the weather, However, a considerable amount may evaporate from the surface of the soil, which in Bonsai containers is large in relation to volume.

Mineral salts in the water, especially lime or calcium, remain in the container and may build up and lead to root damage. You can avoid this by using rainwater as often as you can.

If this is not possible, always give enough water to ensure that a large part of it runs away through the drainage holes in the bottom of the container, rising the soil of excess mineral salts.

Of course you will also be washing away important nutrients and trace elements, so care must be takes with feeding. Trees have differing abilities to withstand salts in the soil; refer to the species guide for individual tolerances.

On hot days a lot of water evaporates from the leaves to cool the tree. Some salts are carried with the water into the leaves and deposited there, particularly in the cells at the leaves edges.

When the concentrations get too high it causes damage, turning the leaves brown at the edges. So whenever possible you should use water known to be low in mineral salts, especially on hot days.

There are no hard and fast rules on how often a plant should be watered, since the need for water varies greatly depending on the weather and the type of tree. Most water is used in hot sun or in strong wind.

Whether it has rained or not, check the soil around the roots regularly as rain will run down the leaves of a tree with thick foliage, missing the container and leaving the soil dry.

The soil surface is a good indicator: if it is only slightly damp or just dry, the Bonsai needs watering. Thus watering is a mandatory part to grow a Bonsai tree

Features of different soil types

Sand : it makes the potting compost permeable. If there is a high proportion of sand, the surface dries out very quickly but underneath the soil will still be wet. This often means that the plant is watered again too soon, which is why sand is not used in large quantities.

Lava granules: It can be used in part to replace sand in the growing medium. These are made from volcanic stone and are light and full of tiny holes which help to retain water.

When not filled with water the holes take up air and thus help to provide the roots with oxygen. Lava contains many trace elements which the plant can use.


Peat: peat is used mainly because of its ability to retain water. It contains no nutrients, but is often prepared with lime and fertiliser. Humus can be used instead of peat. it retains water well and contains nutrients that are good for the plant and a high level of micro- organisms, which give the soil a loose, crumbly structure.

Loam: It acts as a kind of buffer. It can hold high levels of water, without allowing the plant to stand in the wet, and slowly gives this water off again. Nutrients are also held and gradually released to the plant.

Soil with a high level of loam compacts very quickly and when dry it is rock hard. A granular loam soil from Japan called Akadama can be used instead of the usual loam in the soil mixture; in Japan it is often the only ingredient used for many trees.

Akadama has a grainy texture which means that it does not compress quickly. It also has the positive features of loam- the ph value is neutral and the level of organic content and nutrients is very low.

Repotting of Bonsai

The best start for a young Bonsai is to spend its first few years planted in the open garden. Every other year in spring it must be lifted and the roots growing directly beneath the trunk(the tap roots) must be removed so that only a ring of side roots remains.

These roots, which will eventually form the main root system, now grow much stronger as they have to supply the needs of the whole tree.

Over the next two years the tree will produce new roots and when it is next lifted some of these are cut away again, leaving only those necessary for the future root system.

When the trunk has reached the right thickness, the tree can be lifted from the garden and planted into its first Bonsai container.

If you do not have a garden, you can keep a young plant in a large container or a tub for a few years but you will need to change half the soil every two years. The roots should be treated as described above.

The trunk of a container-grown tree is usually not as thick as that of one grown in the open, but there are certain advantages: container-grown Bonsai are much easier to prune and shape from an early age.

A young tree needs new soil approximately every two years; older Bonsai can be repotted less frequently. The best time to repot all deciduous trees is in early spring before the first leaves appear; conifers may also be repotted at the end of summer.

When repotting established Bonsai you can remove a third of the roots and two thirds of the old soil. Leave the central root ball alone unless the root system has to be improved, in which case you may need to disturb it.

If not, then proceed as follows; use a hook to loosen the roots that are tightly packeed together grow in circles around the container, will now hang down.

Cut these to the length of the roots in the central ball. Partially remove the soil stuck between roots. Now place the plant in the prepared container.

You can put the tree directly on to the base of the container, so long as the root ball is big enough to lift the base of the trunk as high as the container rim.

The roots should not completely cover the drainage holes. Add the necessary drainage material from the side. Finally, water in well.

If the Bonsai is going to be put in a particularly windy position, stabilize the root system by tying in a wire running through the drainage holes. After repotting, protect the Bonsai from the wind and sun for two weeks, and do not feed it. You can explore shortcut ways to grow a Bonsai tree.

Bonsai Pruning

Regular pruning is one of the main methods by which a Bonsai is kept small.
Depending on the stage of development, desired size, and type of tree, pruning is done in varying degrees and frequencies.

How to grow a bonsai tree  from seed

A desiduous seedling is not pruned at all in its first year and only once in its second. Conifers are not pruned at all until their third year.

If you want the trunk of a 3 to 5 year old deciduous sapling to thicken quickly it should be cut back at most twice a year once the new growth has reached two thirds of the tree’s planned height.

This pruning can be hard, depending on the shape of the branches in the crown, and should leave only 1-5 leaves.

If you want to have delicate branches and few visible cutting scars, and you are prepared to wait longer for the thickening of the trunk, then cut back the new growth only when between 5-8 leaves have appeared.

Older, well-developed trees are pruned when the shoots have developed 5-8 leaves.

During normal growth a hormone is manufactured by the tips of the growing shoots and flows under the bast (soft inner bark), inhibiting the growth of buds lower down.

When the top shoot is removed the hormone production stops, enabling the bud nearest the point of cutting to develop. This new bud now produces the inhibiting hormone so usually only one more bud will appear.

As long as the new shoots have already developed 1-3 leaves their tips are removed in late summer. This gives the shoots time to ripen and harden and to produce new buds to survive over winter.

The process of removing the tips is called pinching out and is done with tweezers or your fingernails. If the supply of nitrates in the soil is not too high, the tree will now stop growing and prepare for the winter.

Bonsai feeding

The first feed is given in spring when the shoots begin to show. This can be a fertiliser with a high nitrogen content as the need for nitrates is particularly high when growth begins.

Desiduous trees need more nitrates than conifers. After the first feed, nutrients should be given weekly, fortnightly or monthly, depending on the weather and the type of fertilisers used – for instance, liquid fertilisers are easily washed away in heavy rain so will need to be given more regularly.

The nitrogen content of the fertiliser must be reduced as the year goes on, and by autumn the feed should contain no nitrates at all. To achieve this, different types of fertiliser are used throughout the feeding season.

You might start the year with rapeseed pellets and finish feeding in august with cactus fertiliser, which has a particularly low nitrate content. There is a special potash/phosphate fertiliser which, if given in early autumn, encourages frost resistance and fattening.

It is, however, difficult to get in liquid form and is only available from specialists in exact doses so if you are a beginner don’t worry about using it. If you want to use only one sort of fertiliser you can get round this by giving the tree plenty during the growing season and gradually reducing the amount towards autumn.

Final Words

Now, you have just gained the right knowledge on growing a bonsai tree from seeds. If you don’t succeed the first time, try again. We hope that you enjoyed this tutorial. If you do, please share it with your family and friends.

You can also comment below and share your insights, suggestions, and your experiences in growing tree seeds and creating them as beautiful bonsai trees. Happy tree seed germinating and bonsai tree growing!

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