How to Grow Bonsai From Seed – Acorn to Oak
Here is the year 2 bonsai work required to turn a seedling into a future bonsai tree.
This means cutting off the large tap root, or in some cases using a tourniquet to encourage new roots some way up the tap root.
I demonstrate the tap root chop and the tourniquet method on several different oak seedlings. Pyrenean Oaks, and English oaks or Royal oaks.
I’ve got a lot of different types of oak but they all have one characteristic in common they all have a big fat tap root stay tuned [Music] i’ve got here about 40 different oaks they’re all seedlings from just over a year ago and they all need tap rooting and repotting you can see i’ve done four already so it’s quite a long way to go i’m repotting them into these larger pots pretty good in this bright sunlight in the hot summer we have here in madrid to have a nice white pot reflect a lot of the heat off so by repotting them at this early stage i’m trying to achieve two things one is to get rid of all of the weeds and and the liverwort which is not dangerous not harmful but it really looks ugly and it spreads really easily so i want to get rid of the liverwort and we need to either cut off the taproot or at least prune it down and tourniquet it so that we get a higher root plane [Music] so let’s take a look at how simple it is or difficult to cut off the tap root and to keep the seedling alive we’ll start with what i’m calling an ideal seedling where you have to tap root and you have fine roots growing radially all the way around about one point now in this circumstance it really is simple because you can cut off the tap root and leave all the fine roots however in real life seedlings are rarely that simple and especially oak seedlings which are notorious for shooting down a massive taproom with feeder roots spaced randomly all the way down the taproot which is great for a healthy tree in nature but not great for bonsai now in this circumstance what happens if we just chop off that root well we leave very few fine roots and there’s a good chance that seedling won’t survive till the end of spring now let’s rewind and have a look at a different method which uses a tourniquet to restrict the growth of the tap root below a certain point now tourniquet is just a metal wire wrapped around and tied but not tightly so it’s not immediately cutting off the flow of sap between the tap root and the main stem now this method encourages new root growth above the tourniquet a bit like an air layer would but with the difference that you’re still getting the nutrients from the lower down roots and at this point we can choose to chop off some part of the tap route knowing we’re going to do more the following year then over the course of this year you’re going to get a bunch of lovely fine roots above the level of the tourniquet then a year or two later you can remove the remainder of the tap root leaving your seedling perfect for a future bonsai most of these are actually pironean oaks from the north of spain or i should say pyrenees oaks because it sounds better but these lot over here are english oaks or common oaks or royal oaks however you say them and you can see already that the ink oaks actually grow quite a lot faster they’re all planted from acorns at the same time about a year and a half ago and one more piece of interest here this is a pyrenees oak and it seems to be doing quite a bit better than most of the rest of the pyrenees oaks and what’s different about this one is i planted it in 100 vermiculite and it’s just grown really beautifully i love it the leaves are so healthy and beautiful and green whereas some of the others that i potted in mainly just potting soil and it shows me potting soil is not good even for seedlings we should be using good draining bonsai soil or perlite or vermiculite anything that allows good drainage and allows the oxygen to get to the roots so they can grow better [Music] this one here is an english oak so we’ll see what it looks like on the inside very quick and easy repotting but you can actually see underneath the tap root has come out the bottom and actually grown back in again so because i know i’m going to be cutting the tap roots i can actually literally just cut this one off and it’s springtime plant isn’t going to suffer at all so let’s have a look inside here it’s a mix of soil we’ve got in this one you can still see the old acorn here it’s not necessary anymore there’s the kernel of the acorn the core for the first year the acorn still provides nutrition for the plant so you don’t need to fertilize the whole of the first year really by this year the acorn is not doing much it’s just rotting away and yeah of course this year we’ll need to fertilize a couple of months after we’ve got him now i’m going to try and do a close-up of what this root ball looks like you get very woody twisty roots [Music] so you can see the tap root here has got quite enormous and that might on some trees be an interesting bit of movement but really i don’t think it’s suitable for this kind of oak tree so i’m going to cut it off i need to leave some fine roots and deal with it a bit better next year that roots not doing any good so i’m going to cut it off just here and then hopefully we’ll get more fine roots just around here we want actually the root plane we may put a tourniquet just here so we develop more roots just above the tourniquet [Music] so here’s an example of a taproot that has got done exactly what we don’t want to do which is it’s grown down curved round and then all the fine roots are coming from the tap root and not actually from the main stem which is where we’d want it somewhere so the way we deal with that is to put a tourniquet around here for now just cut off probably just the biggest tap root which is here leave the rest of the fine roots so that it’ll carry on growing fine during this year and next year but with the tourniquet here so let’s just get a piece of wire and tourniquet that round [Music] so you don’t have to twist it very tightly there shouldn’t be a gap but it’s just tight enough so that as this tap root starts to fatten it’s going to force a lot of fine roots to come out and then that is where my future roots my future nebari will come out just above the tourney kept [Music] and then we’ll leave it in that pot for about two years check the roots again so there we go the difference between granular soil and dense potting soil i can’t compare see there’s fine roots here it’s just developed so much better much more healthy leaves you
