Growing Bonsai Trees In the Ground

One way to quickly get thick, tapering trunks that can be used to make good bonsai trees is to grow them in a field.

What is so important about a thick trunk you might ask. After seeing so many sticks in bonsai pots I would say its extremely important. You should keep in mind that as bonsai artists we are trying to create nature in miniature. If you try to describe how you feel when you stand in front of an old oak, an old camphor tree, or a milkwood tree that has been blown over by the wind for years, you will notice that they all have interesting trunks. It’s hard to get them to look like that in a small pot because of how they hold on to the soil and reach up into the sky. We need to use all the visual tools we have available. A thick, tapering trunk helps a lot. Does every trunk need to be thick? No. Sometimes a more feminine approach is required such as when styling Japanese maples. But we still need the trunk to taper to make it more interesting to look at and to show how the tree gets thinner as it goes up into the canopy.

You don’t have to grow plants in the field to get thick trunks; you can also use big wooden or plastic containers. This is the next best thing for growers who rent their homes, don’t have a lot of garden space, or can’t grow in the field for some other reason. If you are limited to large containers then I would highly suggest our Professional growing medium. As its fast draining, loose and will result in rapid root and vegetative growth. During that time, BonsaiBoost is important to make sure the tree grows healthy and strong. Without it, it will take longer to see the results you want.

However without a doubt, trees grow best when they are in the ground. Japan has been growing high-quality trees of all kinds in this way for hundreds of years, and they still do it today.

The Hackberry above grew from a seedling that was treated as a cutting after the taproot was cut out. If you want to learn more about how to start bonsai from seeds, you can buy my e-book. The tree was planted in a plastic pot and its smaller roots were spread out. It was left there for two or three years. In the fourth year field growing was started by planting the tree out into the ground.

If you have the space you can build growing beds like these above. They are made of bricks, which leave holes that can be filled with the right growing medium, which should drain quickly. It is much easier to work low on the trees when the ground is higher. This is especially true for your back.

Be sure to provide sufficient space between trees so their branches can develop as long as possible. The longer the branches become the more and quicker they will increase the girth of the tree. In the right growing conditions your trees may put on at least 1m of growth per year.

You can use styrene, wooden boards, or even plastic sheets if you don’t have ceramic tiles. However, tiles will last longer and be able to be used more than once.

Mound some soil onto the tile. It doesn’t have to be much; just enough for the tree to grow into.

Place your prepared tree on top of the mound of soil. Work some soil into any gaps so that there are no voids. Roots will not grow into large pockets of air so you must be sure to eliminate them.

Pile up some soil on top, and if you want, you can also mulch around the base to keep the soil from drying out all the way between.

In the above you can see several trees which have been planted in this manner. There is about 1m between them as they are quite developed trees already.

Since you got rid of so many roots, the trees are at their weakest point right now. But trees grown in the field have a lot more energy than trees grown in pots, so Chinese maple and hackberry can handle the rough treatment without any problems. Trees which are more fragile should be given more careful aftercare, including frequent light watering.

Don’t use fertilizer on the tree at first. Once it’s settled in and there are clear signs of new growth, then you can use fertilizer. Organic, slow release fertilizers are advisable as they cannot easily burn the sensitive new roots.

The tree will not grow very quickly in its first year after being planted, but it will grow much faster in its second year. The trees will grow even faster the next few years, until you have to dig them up again around the fourth year. At this point, the focus should be on developing the branches and trunk line, which means letting the tree grow as long as it can. The longer the sacrifice branches become the more they will thicken the trunk.

When you lift the tree, you lose height and cut back the sacrifice branches. This is called a “trunk chop.” It’s not necessary to shape the cut when you do the trunk chop, and it’s not important where you make it either. The tree will die back to a certain point, and then it will send out new growth. It doesn’t make sense to shape the cut if you’ll have to do it all over again in a year or two, when the new trunkline has set in. There are a lot of books that show this, but I’ve learned from experience that it’s just a waste of time. However, it sounds like a great idea, which makes it very believable.

caption. Field grown Chinese Maple. You can clearly see the three spots on the trunk where it was cut and growth then resumed. Here I am preparing it to go into a wooden box I prepared for it.

Don’t cut the trunk until the part that’s left is at least two-thirds of the thickness you want it to be in the end. In general, you might want to cut the tree’s trunk for the first time when it’s about a third of its final height. However, this will depend on the style you’re going for.

Just before the process is over, when the trunk has reached the right size, you may decide to cut down on the time it spends growing in the ground before you dig it up and prune it. This is because you need to think about any cuts and scars you make now, because the big scars you made when you grew the tree in the field will be very hard to get rid of once the tree is in a bonsai pot. I would suggest allowing branches to develop just a little further along the trunk, above any major cut. This will cause sap to flow aggressively at that area and will result in quicker healing.

You could also cut off branches before they get too big to avoid leaving big scars on the trunk as it grows older. This would make the cut smaller. It is also very important to cut with a sharp saw, as this will help the wound heal faster.

After cutting off the branch with the saw, I like to use a root cutter to get rid of the branch stub that’s left over because it’s stronger than a branch cutter.

While in the ground the tree will grow strongly and roots will develop equally as strong. After several years in the ground the roots will have thickened considerably and will be very coarse. For pot growing, we need to encourage feeder roots, which are thin and can pull water and nutrients from the soil, instead of thick storage roots. Also, trees that stay in the ground for a long time will only have these thick roots left. The smaller roots that were closer to the trunk will have died off.

So it’s best to dig up the tree and get rid of the rough roots every three or four years. To do this I use a chainsaw and root cutters.

Ground growing bonsai trees for thicker trunks

Can you grow bonsai in the ground?

You can grow any species of bonsai in the ground, so long as it is able to survive in your climate it will be fine. It can also be at any age and at any stage of its bonsai journey. Young trees are going to be the best trees to plant in the ground to grow as bonsai and are the most common trees to do this technique on.

How to plant a bonsai tree?

You may choose to plant a bonsai seed in the ground or plant a smaller bonsai tree. A seed of a young bonsai tree stands a chance to grow a full root system and later extend to a big tree. If you choose a mature tree, it’s unlikely to grow larger roots because it has reached its maximum length.

Will a bonsai grow into a full size tree?

A bonsai will try to grow in to full size tree if you let it. One of the main reasons a bonsai stays so small is due to the limited growing space they have in a small pot. Once you plant a tree in the ground this space restriction is removed and they will quickly start to stretch out and take advantage of the endless room available to them.

What is bonsai gardening?

Bonsai gardening is a unique horticultural practice that combines your passion for nature with the artistic expression of shaping and training trees. It involves the careful cultivation of young saplings or plants in the ground for a few years, before they are uplifted and placed in suitable containers for training.