What's in the bag?

[Andrew Legg]

OK, folks, so in another thread here I ask questions abnout callistamons and repotting etc, but it brings me to a more generic question. How do we know what;s in the bag?

You get a plant in a black nursery bag - it's fairly sensitive to root disturbance, so how do you get it into a bonsai mix in a shallower container? I've seen people saw off the bottom half of the bag and hope for the best, but that seems like a dodgy approach to me in case of a major tap root. You could of course open it all up and bare-root it, but what if it does not want the root disturbance? How do you actually know what you've got? How do you know what roots are where and how much soil you can take out? I was thinking of getting the fellows at work to make me a 3D imager to create a 3D model of the root structure, but that somehow seems like overkill!

Any advice?

Cheers,

Andrew

[shibui]

Yes, very definitely overkill Andrew.
The way I see it, if a plant cannot tolerate root disturbance then it is not going to make much of a bonsai because you are going to want to rootprune every few years to renew roots and replace potting mix.

Cutting through the middle of a rootball of a plant you have purchased is inviting disaster. I have frequently seen plants that were potted on by placing the original rootball in the bottom of the larger pot then top up with new mix. When you cut through the middle you cut through the (now buried) trunk leaving roots separate to the top

[kuregtr]

I wouldn't cut throught the middle. I guess you could start cutting from the bottom of the bag and work your way up layer by layer feeling for the root ball as you go.

[Dario]

Hi Andrew, I take it out of the pot and then gently uncover the top soil until I hit the start of the major roots/nebari emerging from the trunk. It can be difficult depending on how compact the soil is (if it is really compacted I use a water/spray bottle and squirt to soften the soil a little). I comb the roots radially whilst doing this.
Using metal tweezers (or a bamboo chop stick)I also poke them into the top outside edge of the soil and wiggle them, loosening the soil all the way around the circumference (outer most edge of soil).
I then rake the tweezers length wise (vertically) from top to bottom on the outsideside of the soil. I also poke the tweezers into this area too if the soil is compacted and wiggle to loosen (working from top to bottom)...can take a while.
Once I have done all of that, I turn the it over on its side and work from the bottom upwards. I am a bit more aggressive at this stage but I do try to work my way from the middle to the outside raking and removing soil. At this stage I do a bit of cutting of roots as I find the big ones that are growing downwards through the middle of the soil and also on the outside of the soil.
Working from the bottom up inside the soil you can work out where the major roots are. If it is a species that you don't want to bare root in one go etc, you can still leave a good amount of soil around the roots that is pretty much intact.
Then I soak the remainder in seasol/water etc (you can also hit it with the hose but be aware of the pressure/strength of the water jet etc) and take it from there depending on what you encounter (how compacted the soil is too) and the species of tree.
This is how I do it anyway, and I did it on a fushia today although it took a bloody long time! Hope that made some sense.
Others will do it differently...Alpine has a good thread on slip potting if you search for it, he slices down the side of the root ball and loosens it up and spreads it out, but you will have to read the thread for the details.
Best of luck. Cheers, Dario.