Re-potting a Bonsai Plant

Re-potting a bonsai tree, although not hard, is sometimes an adventure, and you never know what you are going to find when you lift that plant out of its container. If it has been a while since you re potted you may find a bunch of brown roots wrapped around themselves and the inside of the pot. You may also find that most of these roots are of poor quality and very dry with voids in the soil. Some of these roots may even be rotten. Or, you may get very lucky and find healthy roots. It is always an adventure.

When do we repot? Re potting is done at three different times. Most common for beginners is the re potting from a nursery pot to bonsai training pot. The second instance is from a bonsai training pot to a finish bonsai pot, and lastly and most common for bonsai enthusiast is the 2 year maintenance re potting. For the purpose of this article we will focus on the second. The change from a bonsai training pot to a finish bonsai pot.

Before lifting your plant out of the training pot, disconnect the wires that are holding the plant to the pot AND the wires that hold the drain screens.

This is best done by clipping the wires from the bottom of the pot. Wire is cheap and the damage that can be done to fine roots by trying to untwist wire is not worth the chance so just cut the wires. Secondly, take a root knife and cut or scrape around the inside edge of the pot to loosen any roots that may be holding on to the pot. Gently tap the sides of the pot with the wood end of the root knife and gently hold the plant as you tip the pot upside down. The plant should simply fall into your hands. If it doesn't, push your finger through the drain holes to make sure the old wire isn't still holding.

We suggest, if your plant is healthy, that you clean off all of the old soil. This is best done with a root hook and a chopstick and a gentle power wash. If the tree is not very healthy then a gentle picking with the root hook and the cutting of any old dead roots is all that should be done. After the root work it is time to soak your plant. This is one of the places where we differ from many of the other "experts." We do not like to hurry this process and may soak a plant as long as 2 hours but always at least 20 minutes. We soak in a mild solution of Dyna-Gro K-L-N Concentrate and water or a Super Thrive mix. In the past we have used B1 or the new HB101 Organic Growth Enhancer. Any of these products will accomplish the goal of re-hydration and vitamin infusion and hasten the re-rooting process.

We use this soaking time to ready our pot. This is instance two where we differ from the traditionalist. Old school bonsai guys prepare their pot before they even remove the plant from the training pot. This is just not practical for a number of reasons. To start with, you have no idea what the roots look like. How can you prepare a pot or even select the correct pot for that matter without first seeing what the finish plant looks like. If the roots are damaged badly we may want to rethink what kind of soil we use or what size of type of container we use. Take your time, soak you plant then prepare you selected pot.

Do NOT turn a pleasant afternoons Zen experience into a controlled chaos.

OK, back to the pot. We place clean drain screens and new wires in the drain holes. Based on the size and shape of the tree we then decide on how we will secure the tree to the pot. if the pot has tie holes, as many of the custom pots we use do, we will choose a proper selection of these for our tie-down wires. If, like in most situations, the pot only has the two drain holes to use than we will use a single large loop wire or if warranted two loops, in an "X" pattern, to secure the tree. The main goal is to secure the tree so it will not move.

Next we ready our soil. As most of you know we suggest a structured soil. Make a mound where the tree will be placed. Make it about as tall as the pot is deep, it is easier to push the plant down into this mound then it is to add soil under the plant later.

Now take your tree from the soaking solution and place it on the mound of soil and push in down gently. Pay close attention to where the final soil height will be, is there enough soil in the pot? If you buried the roots right now would the base be displayed at the proper height? If not add more soil. You also will want to make sure you are displaying the plants proper front (best side) and is the angle good. If you are happy then it is time to secure the plant.

There are a couple ways you can do this. First, if most of the soil has been removed it is best to thread the tie-down wires up through the plant. Now we will assume you have four ends, two "X" pattern tie-down wires. Take the two ends of the first wire and come across the larger roots close to the base. In many cases I use plastic tubing on the wire to protect the roots. cross your wires to start the twist and use your wire pliars to snug it. (not to tight) Then repeat with the other set of wires on the opposite side of the tree and gently snug.

The second way to secure your plant is the "top ring" method. We use this method quit frequently on trees with tight root balls or very delicate roots where the only strong roots are close to the base. This method will require slightly larger diameter wire for your tie downs because you will twist them later and small diameter wire will break during that process. First thread a thick wire through a piece of plastic tubing and very loosely wrap it around the base of the tree and twist it together making a ring, this will become your anchor. Now bring the tie down wires up through and loop them over and around the ring, here is where the thicker wire will come into play. Once you have secured all the tie down wires, using your wire pliers, from the bottom of the pot twist first one of the tie down wires to tighten then the other. This will pull the ring down tight and hold your tree in place. This sounds complicated but it is really quit easy once you grasp the technique.

Now double check the inclination of the tree and if you are happy continue to add a little bit of soil using a chop stix ( I also use my fingers here on larger plants) to fill any voids under the tree and between the roots. Repeat this process until there seem to be no more voids. Now, check the wires once again, the tree should not move once you have it tightened correctly. Continue filling in your soil mix to the desired height.

Now it is time for a good soaking! If you have a water can you can use pour the Super Thrive solution from your presoaks or just use cool water. make sure you water thoroughly, water should exit the drain holes.

That's it! Place your newly re-potted bonsai in a partly shaded area for the first week or so to let it recover. In about a month you can start a fertilizing schedule.