Eucalyptus polyanthemos - Buying native nursery material

[Rory]

Eucalyptus polyanthemos - Purchased from Plants Plus in Castle Hill, a progression and example of what I look for when buying native material from nurseries.

This is a thread to show how I work Native material from nurseries. Generally speaking, if its the first initial purchase, I try to avoid removing roots. (if the material is a fair bit older and harder to separate the roots, then you may have to remove a lot of roots to try and separate them. But its best to avoid older and more compact roots on older stock if you can. But I prefer to keep root removal to an absolute minimum, and only separate the roots so it reduces the initial shock on the tree. After a year or two, that is when I usually reduce the roots more. But this first repot, is just to separate the roots and leave as much foliage on the tree as possible. However if you have no choice and you have to remove quite a lot of roots on the first day, say 50-60% of the roots, then it would help to perhaps reduce the foliage by about 20-25%
This also depends on the species. If I’m working a Banksia or a Casuarina, then I can comfortably remove a lot of roots and be confident the tree will survive. But with stock like Eucalyptus / many Leptospermum / Hakea / Grevillea and others…. I try to avoid much root removal at the first attempt.

Choosing material:

So the first thing I look for when purchasing native material from a nursery is the trunkline. But it’s not the most important. If it has a lot of branches down low, then the trunk-line will probably change over time anyway as you shape it and cutback each year.

-The most important thing to look for is the first root spread at the top. I very gently dig down around the base to see where the first roots are, and to see if it has a decent spray of roots coming out at the same area. This is where you can usually tell if its been slip-potted from a young age. Often tubestock is left to become pot-bound before its slip-potted into larger pots. You need to make sure that you can feel individual roots coming RIGHT OFF THE TRUNK, and not just roots that are circled around and around the trunk and then coming out radially.

-The next thing to look out for, is how easy is it to get your finger into the mix. If its like concrete, I no longer bother and I put it back. It means its probably pot-bound and not much use for bonsai, or its just going to be too much risk when separating the thick and solid roots. (Pot-bound means the roots are so compact and a mess, and they are entangled in on themselves). So if you can easily put your finger into the mix and feel individual roots then it will be a lot easier to work with.

-The last thing I like to check is that the material has quite a few branches down low for you to work with. If it doesn't, then make sure you know whether its material that will backbud on the trunk if you do a trunk-chop later on.

Poly1.jpg

This is a Eucalpytus polyanthemos. There were others there that had thicker and better shaped trunks, but the roots were terrible when I put my finger in and felt around the base of the trunk.

Poly2.jpg

This is what it looked like after I took the pot off. Notice that the roots have only just started to circle around the inside of the pot. You know that its going to have an easy root system when you can easily put your finger deep into the mix. This is confirmed by seeing it hasn't continually started circling around and around the pot and back in on themselves.

Poly3.jpg

All I've done at this point is gently ease away at the mix and try to expose the roots to see where they go. I have very gently worked the mix at the base, by using a very soft spray setting on the hose and using individual fingers to rub away the mix and expose the roots.

Poly4.jpg

Here you can see the roots at the bottom have only just started to fuse together. These are pretty much the only roots that I will remove.

Poly5.jpg

And this shows you the small amount of root that I removed from the bottom....just enough so that I can then continue to ease apart the root system.

Poly6.jpg

This shows you the progress of just using the hose on a gently spray setting and continuing to remove the old mix from between the roots.

Poly7.jpg

I have continued to gently untangle the roots and remove the old mix. With many Eucs, they will have one or maybe a few tap roots (thick tap roots that go right down). I used to cut them off at the first repot. I no longer do this. I remove tap roots on the next repot in a year or 2. I've lost a few Eucs from cutting the tap root too soon at the first repot from nursery material. Again, for me with native nursery material, the objective is just to separate the roots, not remove them. This way the shock on the tree is minimal and it has a good root system and healthy foliage to give it the best chance of survival.

Poly8.jpg

This shows you how much root was on the tree, and how big the pot was. Its often surprising how little roots a tree needs to support so much foliage. And in my opinion its a misconception that you have to remove a lot of foliage, even if the resultant roots are removed by 40% or so.

Poly9.jpg

So now it is gently placed on a bed of mix. I have the mix like a pyramid in the pot, so the roots gradually taper down along the pyramid. I ease apart and keep the roots spreading out radially.

Poly10.jpg

I then add the first handfuls of washed river sand as you can see. This will give the root system a binding strength and help with drainage.

Poly11.jpg

Once you gently spray the river sand with water, it holds the roots in place. Allow all the water to drain out, before you release the roots from the position you wanted them in. This way the roots wont retract back to their original position, and it binds them to the position you want them.
Then I add potting mix, and more river sand together.

Poly12.jpg

I repeat this again and again with each layer until the root system is covered.
Usually I wouldn't put a native with this size root system into a large orchid pot like this one. But this is a Eucalyptus. As long as you have good drainage with the river sand, and a decent draining mix it will be fine and you wont have problems with it being a fair bit over-potted. Eucalyptus will grow incredibly quick and are very thirsty. It will be pulling the water out of this pot very soon once it has recovered fully.

Poly13.jpg

This shows the tree with all the foliage left on.


A year or two from now it will be repotted. This is when I will heavily reduce the roots and keep mainly the first section of roots and remove the roots growing below this top level. The roots growing below are now there to help support the recovery quicker. They are sacrifice roots, which will be removed later on.
With all my natives, I usually leave most of the foliage on. However with Eucs, you might get some dieback after the first root prune by leaving all the foliage on it. At this stage there is no real structure to the tree, so if the roots don't recover quick enough to support the new growth on the ends, then dieback on the outer areas isn't a concern for me at this stage.

[Promethius]

Very clear, very helpful. Cheers!

[Rory]

All I've done is trimmed the roots a little and placed into a gorgeous bonsai pot by Adam Luczak. (Poland)

Euc polyanthemos 1-02 17Nov2023.jpg

17Nov2023