How to Grow a Great Nebari Japanese Bonsai

In this video, I show you a simple trick that you can do when you repot your bonsai tree in Spring, to help develop great looking nebari – those beautiful surface roots that make a bonsai appear like a real miniature version of a real old tree. Good nebari also has the advantage of thickening up the lower trunk base, giving the bonsai more taper in the trunk, which again gives the illusion of a much older tree.

In this video I’m going to repot these two Deshojo Japanese maples and I’ll talk you through the process. Enjoy the video! Early spring – just as the leaf buds are swelling or beginning to unfurl – it’s the best time to repot a deciduous tree because all the sap is surging up the trunk to the branch tips and that’ll continue even if you chop away a lot of the roots Let’s pause right there and let’s go back in time to this exact moment one year ago when I removed this japanese maple from its pot to find that the roots hadn’t filled the pot yet so I decided to put it back in and let it grow for another year so back to now in march 22 you can see that the roots have now filled the whole pot and it’s nearly pot bound so it’s definitely time to repot it and prune those roots first i’m raking away the easy to remove granular soil and i have to keep misting the roots to keep them damp in this dry air and now dunking the whole root ball in water to get rid of some of the clogged up soil from the roots and let’s just stop it there so i can show you the problem with these roots now they’re undoubtedly healthy roots but the problem is they’re growing upwards from what would otherwise be the nebari so we need to fix this and it’s time for some whiteboard action here’s our lovely bonsai maybe a couple of years ago and we decided we wanted to get a nice flat root plane so we planted it right on top of a ceramic tile then we added some soil and we let the roots grow out for a couple of years before repotting again and now you can see the problem that we caused while the trunk slopes very nicely into the nabari we haven’t allowed the roots any room to grow downwards and by covering them with soil we’ve actually encouraged them to grow upwards so in this repotting we need to plant the tree a bit higher and then wire down all of those sticky up roots first we’ll prune off the worst offenders, then we’ll use a system of wires anchored to the bottom of the pot.

.. and this isn’t the best part: the real trick is coming up in a minute. Firstly I’ll show you what’s wrong with this method. When I tighten those wires to pull the roots down it’s just going to have the effect of pulling the whole trunk down into that soil, and we’re going to have the same problem all over again that happened before! So how do we deal with this? and here is the real trick: We use a small round stone or pebble placed just underneath where you’re going to put the tree.

And now we do all the same wiring system except this time when we tighten those wires it’s going to pull the roots down to tuck them under the soil but it’s not going to pull the tree down because the stone is there holding the tree in place.

After a couple of months we’re going to need to remove the wires to prevent them from scarring into the nebari and we also remove a layer of topsoil to expose the nebari and to avoid having the roots growing up again.

And after another couple of years just look what beautiful nebari we’ve developed! I hope you enjoyed this little animation and if you did please don’t forget to subscribe for more like this. Here we go then, removing the obvious upward sticking roots that one there for example and there are two more so I’m just leaving the one that goes diagonally downwards.

And there’s a root that’s emerging sideways out of the thicker nebari we just want to keep the roots that go radially away from the trunk and there’s one that sticks up before it goes down it’s got to go just removing the roots that go directly down from under the trunk base and now before potting up we need to give the roots a profile cut just around the edge to make sure they’ve got room to grow out over the next year or two so here’s the pot and for this exercise I’ve actually put in four wires two of them lengthwise and the other two anchored on thicker pieces of wire through the drainage holes so you see four pairs of wires sticking up and before I put in the prop stone I’m just putting in a base layer of soil and now the moment you’ve been waiting for: the prop stone.

And I chose one that was just bigger than the trunk base, and slightly rounded on top. And we still have to cover the stone with a mound of soil to make sure there’s no gap between the trunk and the stone.

Now I’m not gonna lie: feeding four pairs of wires between the roots was quite a fiddly business tightening each pair of wires in exactly the right place and snipping off the excess also using the twisted wire ends to help hold the roots down.

And giving the roots another misting before adding more soil. And poking in the soil to make sure it gets into all the gaps between the roots. The soil I’m using is small grain akadama mixed with small grain kiryuzuna about two thirds to one third.

Final bit of tightening to make sure the tree doesn’t move for the next month or two and the top dressing is pure small grain akadama, and soon I’ll brush the top layer of that off to reveal the nebari and to keep the roots sloping downwards.

And now I’m going to repot this one but double speed because you already know the theory. And you’ll see I’m going to use a smaller rectangular pot because I think it suits the shape of this maple better.

And you’ll also see this one’s already got better nebari too.

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