AusBonsai

Hi guys,

I have a trident maple, about 5 years old (when I purchased it as a twig of 3 years maybe), that seems to be losing it's ability to thrive.

Right now it is a bit of a bush as I am merely trying to increase the trunk's size and nebari. It was all going pretty well and I am pleased with the nebari but still want to increase the overall size of there trunk. I don't prune it much at all but maybe I should have...

For the past two or so years I have had it in a large deep pot with the root base only halfway down (on top of a wooden tile to help encourage radial root growth for the nebari).

before transferring it to this pot, summertime would bring a burst of growth that would never cease to impress me, but in this big pot, it doesn't seem to grow much. Sydney has been having a pretty hot summer so I moved it off the balcony wall, onto the floor. But still, after about a month, it hasn't seemed to grow or produce any buds at all.

Is a month too soon to notice any difference? Any tips on what the problem could be?

The plant is about 180cm tall at the tops of the whips, from the trunk base.

Pics attached!

Cheers!

The burnt tips on those leaves could indicate that it has been a bit dry at some stage.
Lack of vigour could indicate that it is not getting the right nutrients. How often and how much are you feeding it? If it has been in the pot for 2 years it could be close to running out of room for new roots. That can make it difficult for water to soak in properly as well.

Just a note on your technique as well. I note that you say

For the past two or so years I have had it in a large deep pot with the root base only halfway down (on top of a wooden tile to help encourage radial root growth for the nebari).

In my experience tridents are very strong surface rooting plants. When buried deep they respond by putting out new roots right at the surface of the soil level. This usually results in the trunk thickening more where the new roots are. I do hope that your tree is still ok but I would strongly urge you to repot this winter and have a look at what is happening. Maybe even have a scratch around the trunk now and check that you have not got too many roots starting.

Thanks for the quick reply Shibui. However I don't know anything about the issue of having too many surface roots What is the possible problems there?--and just to clarify, the base of the trunk is not below the surface half way, just the bottom of the root ball is at half way (well, when I put it in this pot originally).
I actually haven't given it much fertiliser lately because I figured it was sick and I have been told not to feed sick plants (but maybe the lack of nutrients is the very issue!). I generally give a spoon full or two (per directions for potted plants) of my fertiliser every three months.

Hi Shills,

It may be helpful to get some more clarification from you.

When did the tree loose vigour? Ever since being in this pot? Or just this last season after growing well in this pot for a season or 2?

When you potted it into this pot, did you give it a good root prune, or just put it into a larger pot without disturbing roots too much?

You said you put a wooden tile beneath it, what sort of wood was it?

What sort of fertiliser are you using?

Without having answers to the above questions my guess would be a possible root problem with either the roots totally filling the pot, Tridents can be very vigorous root growers, or the pot being a bit big, your medium is drying out and the roots are rotting. Have you had it out of the pot to see what the roots are doing?

Whenever you encounter the problem of a tree not doing well. Lift it out of it's pot and look at the roots. They will tell you instantly whether they are too dry, too wet or healthy.
If they are healthy looking (white tips everywhere) then your problem is not enough food. Normally, feeding every 3 months is a starvation diet. If you are giving it by the spoon full, I presume it's something like organic pellets? If so it should be every 3 weeks at least. If liquid into a can, every week. If osmocote or similar follow instrutions.

I agree with Mike. I repot my tridents every year without fail as they are growing on. I feed them handfuls of DL or chemical ferts as well as liquid feeds. Check the rootball and if it looks OK ramp up your feeding. Then repot when it is bare or at bud burst depending on your climate and preference.

Sounds like starvation is the probable cause. Check out the roots as advised and let us know how it looks or better still, a photo. Also what fert are you giving every 3 months?

[quote][/However I don't know anything about the issue of having too many surface roots What is the possible problems there?--and just to clarify, the base of the trunk is not below the surface half way, just the bottom of the root ball is at half way (well, when I put it in this pot originally).quote]
The issue is not having too many surface roots, just where they are. New roots sprouting at the surface can be great when they replace poorer nebari that has been buried but if you already have good spreading nebari then you are wasting time growing new roots above it and there is a risk they will not be as well formed.
However you have clarified that the surface roots are at the surface so no problem.

Maybe I interpret your words wrong but I thought you also said the rootball has a board under it halfway down the pot? If that's correct what is the point of a board so far down?

Shills wrote:before transferring it to this pot, summertime would bring a burst of growth that would never cease to impress me, but in this big pot, it doesn't seem to grow much. Sydney has been having a pretty hot summer so I moved it off the balcony wall, onto the floor. But still, after about a month, it hasn't seemed to grow or produce any buds at all.

Hi there Shills,
As I understand from your first post, about a month ago you moved the tree from the balcony wall (full sun/morning sun/afternoon sun - dependent on aspect) to the balcony floor (fully shaded, ie no direct sunlight), is this correct? And it has not seemed to grow with it's usual vigour, hasn't had good shoot extension and produced as many buds? Has your tree been getting the sunlight it needs to grow?

It is a Trident Maple, with it's current foliage load, in new soil, in such a deep container, watered adequately, I would think it is capable of handling just about anything little old Sydney could throw at it in regards to temperature. So moving it may have not been necessary. It needs sunshine on it's leaves and soil to flourish, in the very least a good hit of solar radiation in the morning. If you have had it in a soft location for a month, re-introduce the tree to better light gradually, observing leaf condition and soil moisture daily.

When there are signs of life, feed as the others have suggested.

Hope this helps.

Cheers,
Mojo

Ok but can we talk about that exquisite Moss?

Hi all.

Thanks for the replies! I thought I posted a reply to some of the questions but checking back now, it doesn't seem to be up. So to try again:

The tree lost vigour since putting it in the big pot about two summers ago.

I have not pruned it ever really. Because I was putting it in a bigger pot I thought the roots would just happily expand into the new space. I wanted to grow the trunk overall so avoided pruning. In hindsight maybe some pruning would have been a good idea.

I put a wooden kitchen chopping board under the root based. Maybe it is made of pine or another light coloured wood? In hindsight I should have pruned the roots back closer (upwards) to the trunk but didn't, so the wooden tile is about halfway down the pot's depth.

I use a fertiliser called 'Hortico All Purpose Compound Fertiliser', No good??

I moved the tree to the shade (some morning sun) about a month ago because I thought it was getting to hot to thrive. But the lack of vigour in general has been for the entire two years of time in this big pot.

Some of your mention checking the roots out. Its a pretty heavy tree/pot so I have avoided that notion, but maybe I should just bite the bullet and dig it out.

And thanks for the moss compliment! It is the original moss from when it was just a twig. Because I haven't ever root pruned it, the moss has been growing intact on top of the roots even when I've changed pots.

Some of your mention checking the roots out. Its a pretty heavy tree/pot so I have avoided that notion, but maybe I should just bite the bullet and dig it out.

You shouldn't need to dig it out. Normally if you hold it up by the trunk and tap the rim of the pot the pot will drop off and you can check the roots growing on the outside of the rootball. With a healthy rootball the roots will hold the potting mix in the same shape. Then just drop it back into the pot.
Even if some of the mix drops off it should still just go back in the same pot without hurting the plant.

If the whole root mass falls apart after 2 years in the pot something is really wrong.

Hi Shills,

Just wondering what made you to decide to use a wooden block underneath, instead of maybe a tile (or something else that does not hold moisture)? I'd be guessing that the block may be staying a little to damp with its new position in the shade possibly affecting the roots around it if you're not careful.

When you check the roots you said you will "dig it out". I can't be 100% on what you meant by this but if it were mine I'd simply lift it straight out of the pot as one in order to view the roots that you can from the outside, without disturbing them. Once viewed from the outside simply place it back into the pot as one.

Can't remember if you said it already but what sort of mix do you have it in? Is it free draining? How long does it stay dry in the old and new location? Is it organic or inorganic? What is the airflow like in the medium? How long does it take to drain when watered? etc.

Also you said you've avoided pruning the tree. A little hard to tell but it looks like it has some reverse taper where it's had a few major branches come out. I'd be careful of how long you let them go or it may get too far gone to correct. Like I said hard to tell so ignore me if that part isn't relevant.

That's some lush looking moss. Good luck with the tree!

Cheers,
Pearcy.

I love the green moss!

Shills wrote:

I use a fertiliser called 'Hortico All Purpose Compound Fertiliser', No good??

NOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Never use compound fertilizers on potted plants. They are designed for vegies in the ground. The release of salts is MASSIVE and can kill a small potted plant overnight.

So I think I'll make a move to take it out of the pot. Its quite heavy and unwieldy but I'll think of something... Can I do it at this time of year? And if it turns out the roots look bad, what should I do (can I root prune the bad bits off this time of year?).

I used a wooden block because it was the right shape at the time. I did cover it in plastic to stop it absorbing moisture but, yeah, in hind site, a different material than wood would have been preferable.

The soil is pretty free-draining. Water runs out fairly quickly. I use a pre-made bonsai mix. I know they are expensive but I only have one tree and its hard and confusing trying to find the right materials for creating your own at regular nurseries.

Reverse Taper? Oh no! I think you are right. I didn't know that was a thing, but it does look like I have an issue there. I might have to think about cutting off some of the large trunk forks.

Oh damn! wrong fertiliser too? Can you tell me what product is more suitable? (can I reverse the salt effect issue?) I have used it ever since the plant was bought without killing it (fast I s'pose), so it would be great to have something healthier for it.

Thanks!