Tip of the Week  #23

Paul from Baltimore asked the following question:
I am a relative newcomer to Bonsai, so my knowledge is quite limited. I have three trees of my own that are doing quite well, hopefully in part due to the fact that I have cared for them as meticulously as I know how. Recently, a well meaning friend gave me two trees that exactly fit the description below that I copied from your website:
"PLEASE, avoid hardware chains, lumber yards, super markets, department stores etc. They tend to offer mass produced, unacclimated bonsai in cheap plastic pots with gravel glued to the surface."

These tree are both in cheap plastic pots with glued gravel. They actually look quite healthy, but I suspect that they won't remain that way if I don't get them out of the glued-on gravel and into a proper soil mixture. My question is this:
Should I repot them ASAP, and if yes, is there any critical advice you could offer for doing so with as little possibility for traumatizing the trees?

This type of mass-produced bonsai absolutely need repotting if they're to have any chance at all to survive. They're usually in either plastic pots or inexpensive ceramic pots which are glazed inside & out. These pots inhibit oxygen absorbsion by the roots, as does the sheet of rocks glued to the top of the soil, which also prevents water from getting into the soil. The first step is to immediately rip off the glued-on gravel. Use whatever tools (screw driver, pliers etc.) necessary to get it all off. That will allow water to get in, and the roots to breathe. If the bonsai is in a plastic pot, you'll need a stoneware bonsai pots for it. If it's in ceramic pot and the pot is glazed, make sure the inside and underside of the pot is not glazed. If the bottom and/or inside is glazed, it's not a real bonsai pot, and should be replaced. The same size pot to slightly larger is best. You'll also need some Super Thrive Vitamins to help easy any shock, and begin healing the roots, a misting bottle, a chopstick (pencil, knitting needle or any similarly shaped object) and two or three pounds of bonsai soil, depending on how much larger the new pot is.

Once you have the above supplies, place a piece of screen over each drain holes in the pot, and sprinkle a thin layer of bonsai soil in the pot. Gently remove the bonsai from it's current pot, being careful to avoid breaking up the root ball. With the chop stick, begin scraping off some of the old soil from the top, bottom, and around the edges of the root ball. Try to salvage any roots that stick out from the ball. It will minimize the shock. Once you're done with this step, you should have a considerably smaller soil ball than when you started. If the above has taken more than 5 minutes or so, mist the roots slightly with water that has one drop (no more) of Super Thrive added. Turn the bonsai around a few times. One side will look best. That should be the front of the bonsai. Place it in the pot. If it's too low, take it out and add more soil to the bottom of the pot. Holding the bonsai with one hand, fill in all around the soil ball with bonsai soil, firming it gently with your fingers as you go. When the pot is almost full, start poking the chopstick into the new soil (making sure to avoid lifting the soil ball up because in this case, "what goes up won't come down.") Poking around with the chopstick will help get rid of any air pockets in the new soil. Continue adding soil until the pot is full. Add moss or gravel (not glued on) to the surface, and it's done.

Water your newly potted bonsai (up to, but not over the rim of the pot) for 15 to 30 minutes in water with Super Thrive added at the rate of 1/2 teaspoon per gallon. This is for the first watering only. Future waterings should have only one drop per gallon added. Find a bright location without direct sunlight for a week to 10 days. After that, begin re-introducing it to sunlight a little more each day or two, until it's back to it's normal location. Avoid plant food for a month whenever repotting, there's plenty of nutrients in the new soil. Once the month has passed, go back to a normal feeding schedule which is determined by a combination of the type of tree, the time of year and your climate.