How To Do A Successful Slip-Potting

Sooner or later you’ll encounter a situation where you’ll need (or really want) to move a tree from a nursery container to a bonsai container out of season.  This can be done with a very high success rate, provided you bear in mind a few key principles.  In this post I’ll show you how I moved a Bald cypress from its nursery pot to a bonsai pot because … I really wanted to.

First of all, it’s important to distinguish between slip-potting done in an attempt to save a tree’s life, and one done because you know the tree won’t mind and you get closer to your goal faster.  Let’s focus on the latter.

Consider these factors before you undertake the slip-potting:

  • Is the tree well-rooted?  You can tell by the strength of the growth, plus you can poke around in the root zone for clues
  • Is there enough time remaining in the growing season to allow for more root growth in time for fall dormancy (for deciduous species)?
  • Is the root mass of the tree shallow enough so that you don’t have to remove more than a bare minimum of roots?
  • Do you have a pot the tree will fit in without any drastic root-pruning (no root-pruning is  ideal)?

Here’s my subject, a really nice Bald cypress I’m training as a flat-top.  This is one of those trees that I knew just what to do with when I collected it.  I’m sure I heard it say “Flat-top.”

The base of this tree is 3.5″ across, above the root crown, and stands about 35″ tall.  It makes a nice statement.












You may have noticed that prominent dead snag on the trunk.  Looks like Pinocchio’s nose, doesn’t it?  Gotta do something about that, along with the one above it on the right (the one on the left under that living branch will be removed, once it’s served its purpose as a wire anchor).






Making a jin is not that complicated a process, once you get the hang of it.  You want to make the dead snag taper down while not making it look artificial, like a sharpened pencil point.

You can either carve these with a carving knife, or do the rough work with your concave cutters.  Here I’m starting on the top side.



I’ve made an angle on the top of the snag.  Good start.








Now I come up underneath with my cutters, and make an angled cut as I did on top.  Notice I’m also shortening this snag, which it needed.








Now the jin is ready for a little carving to make it look as natural as possible.







This one is done.  It sure looks a lot different that when I started.







The smaller jin above was already the right length.  It just need a little carving.








Now let’s get down to business slip-potting this tree.  Prepare your pot by placing screening over the drain holes, at least one tie-down wire, and spread a shallow layer of soil in the bottom of the pot (mostly in the center).




Gently lift the tree out of its nursery container.  You should see lots of roots, as is the case here.  Nice and healthy.











All of the roots get folded into the pot.  Do not remove any long roots such as the one you see in the foreground of the photo above.  Those roots are feeding the tree, and you want them to keep on doing it.






Tie the tree down, then fill in all of the empty space with well-draining soil mix.  Be careful not to damage any of the roots as you work the soil in around them.  Use a chopstick, but don’t jab it into the soil mass.  Push it in gently, then wiggle it back and forth to get the soil to settle in around the roots.






Here’s the end-result.  I did some light trimming in the crown so I could see how well the flat-top is progressing.  Nice.

The pot is a terrific oval by Byron Myrick.  The size is just right to enhance the impression of height, and the green accents remind me of the swamp.

As far as after-care goes, you can place trees you’ve slip-potted into a shady spot for a week or so.  My experience has been that a well-rooted tree really doesn’t suffer inordinately from slip-potting.

Let me know what you think.  Have you tried slip-potting?  Did you have good success?

8 Replies to “How To Do A Successful Slip-Potting”

  1. Terry Bryan

    Hi Zach,
    I have done this a few times without any loss. I did this 2 weeks ago with my bald cypress that I got from you. The main thing I wanted to accomplish was to get the plant into a sturdier training pot to help it make it through our harsher winters than you have down south. The root mass was nice and firm and I didn’t disturb any of the soil. Other than that, it’s just like repotting and the tree is doing well. Thanks for all of the information you provide.

  2. tim

    This tree is awesome!!! Superb taper and that movement up high really makes the tree. I love how a pot can totally change the whole feel of the tree. I usually cant help myself either. Also I have had quite a bit of luck with moderate root pruning out of season as long as the tree is strong and depending on species. B.c. Would be one. Another would be common privet. I haven’t been able to find a way to kill one of them yet.

  3. Pierre Kaufke

    Good job, Zach. The tree looks fantastic in its new pot. I got to this technique via emergency repotting due to animals having knocked plants off the shelves. It worked then and it still does. I’m glad you are spreading this technique to the bonsai community. pk


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