How to Repot a Bonsai Tree | 25 Tips for Healthy Bonsai Repotting

In this video, I show you 25 tips to keep your bonsai tree alive and really healthy during and after repotting. I demonstrate with a boxwood bonsai.

Is Bonsai Hard to Grow

Here are some tips that will help you keep your bonsai alive and really healthy before during and after repotting it my name’s dave and you’re watching blue sky bonsai stay tuned before we get started on my tips for healthy repotting we need to be clear on what the goals of repotting actually are and when to do it on that subject if you haven’t already seen it please watch that video where i explain the reasons why we do repotting and when the best time to do it and a spoiler it’s spring but you can also repot in summer from spring right through to summer [Music] so let’s get started on these tips and the first one is in some ways common sense it is prepare your stuff beforehand but one of the things you should prepare is a water spray so here are the tools that i use you probably don’t need all of these but when you’ve got a lot of trees to report it helps iron pot in a bucket to collect the old soil and i use either a spatula or a repotting knife to ease it out of the pot to remove the soil i use a root rake or for bigger root systems i use a root hook for root pruning you’ll need some pruning scissors and make sure you’ve got that water spray so that the roots don’t dry out at any stage for potting it up make sure you’ve got your fresh soil ready and something to scoop it with the wire is for holding it still in the pot for the first couple of months and the pliers are for twisting the wires together and finally get a chopstick to poke the soil down into the roots or for bigger pots a big rubber hammer does the trick [Music] don’t water your bonsai just before repotting it because firstly it doesn’t need it if you’ve got the spray handle you can keep the roots moist but more importantly when you’re trying to get all of that old soil off the roots it’s actually more difficult if it’s kind of wet and sticky on the roots so here’s a good example that needs to be repotted it’s a boxwood that i haven’t done for two years it’s already budding out handsomely this spring and in winter the pot actually broke that’s a bit of a shame so i’ve got a couple of new pots to choose between and we’ll repot it now let’s just start by removing the wires here from the mesh okay see how easily it comes out the pot now and pretty easily just put that out of the way and you can see this is becoming pop-bound thick matte of roots at the bottom very healthy no healthy looking roots but you can see by now they’re actually sort of vying for space all around there so good time to repot it now take out the drainage screens and reuse these in the next pot now the moss is so lush and thick look at that it’s just coming off in my hands beautiful let’s put the tree down that is wonderful wow i’m going to store that away now it’s a case of just raking away that soil seeing how the roots are [Music] you need to rake radially outwards away from the trunk on one hand because that helps to remove the soil from the radial roots on the other hand it also helps to untangle the roots and straighten out any roots that are perpendicular to the trunk or winding round the remaining moss that’s here on the tree i do want to take off the trunk when moss creeps up the trunk here it has the effect of making the bark stay humid and when the bark stays humid and damp you don’t get this nice old crinkly look to the bark so it’s a good time to prune the roots of this boxwood because i haven’t done it for two years and they’re looking pretty healthy but obviously it was getting pop bound the roots you can see they grow like noodles in the bottom so yeah this really did need repotting let’s see if we can just rake out the rest of this soil now there’s lots of very good reasons for using granular soil one of them is because it allows much better drainage through the roots and so you’re always getting oxygenated water every single time you water the tree and that’s much better for root growth and much better for the whole tree but another reason for using granular soil like this is because it does come out easier it’s much easier to comb out the roots to rake out the soil from the roots let’s turn the tree upside down have a look underneath now what i’m going to do is put the rake right into the middle and rake outwards so we’re still getting rid of that soil doing it outwards from the center now this is such a good healthy root plane at the bottom and the flatter the root plane of course the better the nebari the surface roots and the shallower pot you can put it into beautiful lovely roots just coming right down from the trunk [Music] [Applause] all right so here’s my root pruning scissors we’re just going to do start with this one that’s coming sort of sticking upwards from the nabari let’s prune that one off [Music] this long one let’s just prune it down to about here you can see it’s a fatter root and it does have feeder roots coming off it but that big long fat root is not actually helping and here’s a few more similar ones i’m just going to do a bit of a profile cut just there so we’ve got quite a few of those bigger fatal routes out of the way another one here so you see a fatter root here and it’s coming straight down from the trunk base and we want to avoid roots that go straight down from the trunk base so i’m cutting that one off larger roots that go straight downwards are going to cause a problem in the future also roots that come down and then go back across the bottom we want to get rid of too so ideally all the roots are coming outwards in a nice radial pattern from the trunk and here this whole lot i’m just going to do a profile cut on those [Music] now when a fat route is starting to turn into what could be a future nebari then that bit there could be useful if we want to consider that to be a future nebari let’s just cut it down to about there [Music] now while you’re actually repotting and here is perhaps one of the most important tips of them all make sure to keep the roots wet at all times wet moist damp humid use a water spray on the roots and that’s the way you keep them wet even when you’re working on the roots the thing is if your roots dry out while you’re repotting it the tree’s health will suffer and there is a chance that the tree could die [Music] okay so i’ve got my spray so i’m just gonna spray it to keep the roots nice and moist [Music] rake out the cut roots and now another tip on keeping the roots wet if you need to take a break while you’re repotting you can safely just put the whole root system in a bucket of water and leave it there over lunch or for a couple of hours and return to the work later on one occasion i’ve left a tree like that overnight and it was absolutely fine but i wouldn’t advise leaving it for more than half a day especially in summer because the water could go stagnant and it’ll slowly starve the roots of oxygen but it’s fine for a few hours now here’s the first pot option let’s see if it looks okay in there maybe maybe not face the front of the tree like that could be let’s move to another one now this one i think is more appropriate and i think it looks good in fact the green goes too let’s prepare the pot you reuse the drainage mesh just wiring the drainage mesh to the drainage holes [Music] right so the other thing i’m going to prepare is to put a wire actually to hold the tree down i’m only going to do one wire but i put it in the corners and then we can tie it over after so an anchor wire is useful when you first repot but then you can’t keep it anchored because otherwise you’re really constraining the whole root plane and the root ball when the roots grow they need to have room to actually push the tree outwards a bit and now my putt’s ready and i think that is the front it’s a nice clean side now i’ve got my soil it’s a mix of academia organic soil which is sieved pine bark mainly so they’re all granules of about three four five millimeter size there’s a little bit of pumice and volcanic in there let’s just put a base layer on pile it up in the middle a bit and then we’ll push the tree down on it the other thing of course at this stage we need to see if i need to give it a bit of a profile cut around the edge this is the front of the tree so we’re gonna push it down here into the soil so here’s my wire to tie it down to kind of feed it in between the roots i’m gonna make sure that it is gonna hold the tree in place for a couple of months for a few months so put it over the back of the roots and just twist it around it’s very good give it a last spray spray the leaves as well make sure they stay humid and more soil chopstick now we poke the soil right down into the roots and as we do this gradually the nebari seems to start emerging again which is nice that’ll do now put the top dressing on let’s just sprinkle that on the top this is a very fine grain for the topsoil these are about two millimeter size or three millimeters wax as you can see i’m actually not filling it right up to the top and the reason is is because we need to give the roots that space to grow over the next two years of course the wire that’s holding it down right now i’ll get rid of that in a few months so there we go one re-potted boxwood bonsai now we give it a good watering put it back on the bench [Music] the first time we water it through very thoroughly so we get quite a lot of water draining out of it after repotting it put it somewhere in the shade just for a few days somewhere where there is light but definitely no direct sunlight and mr leaves quite frequently with a fine spray and the reason is is because you want to keep that moisture in the leaves as far as possible and maybe stop or slow down the transpiration in the leaves while the roots are recovering if your tree does lose a few leaves not the end of the world sometimes up to half of them might actually start yellowing and drop if you’ve done a really severe route pruning and you’ve really not left much roots at all then what you can do is actually put it in an incubator for a couple of days three days after repotting and my last tip is sometimes forgotten but here we go don’t use fertilizer for at least a month up to two months after repotting they don’t need fertilizer after repotting and in fact the fertilizer could actually jeopardize the health of the bonsai so just steer clear of fertilizer for that bonsai for a couple of months thanks for watching hope you enjoyed it if you did please hit that like button and don’t forget to subscribe if you haven’t already subscribed see you in the next video

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