Fertilising in Autumn

[austindrake]

Hi all,

Looking for both a bit of clarification as well as any friendly critique of my regime from those who are more learned than I am.

95% my trees are in development and so I am pushing for as much growth as I can in deep plastic pots (sadly, no space from a grow-bed). Currently, my regime through the Spring til Autumn is:
- Fortnightly Eco-Organic Eco-Seaweed liquid tonic
- Fortnightly (on the next week) Charlie Carp
- Monthly GoGo Juice
- Monthly top-up of Neutrog Gyganic pellets (at the appropriate dosage for pots and divided into monthly amounts)

When the "season ends" I plan to switch to Seamungus during the end of Autumn, Winter and early Spring before switching back to Gyganic. Unfortunately I cant find a definitive point where I should stop liquid feeding as here in Melb the winter is so mild that I dont believe theres a point I need to stop to let my trees harden off.. or is there? Should I simply stop fertilising next fortnight, halfway through Autumn? Or is it worth pushing out until my trees lose their leaves, even if it takes until early Winter for that to happen?

As always, any advice is appreciated!

[Stevie_B]

As I understand it, the idea for fertilizing into autumn is to allow the plant to store nutrients so it can begin its new growth cycle with vigour.
If your plant has already gone into dormancy then it won’t be taking up anything through the roots, and fertilizing is largely wasted.
In ipswich SE Qld we don’t really get much of a winter so most of my trees don’t really go into dormancy, especially the figs and some natives. So I fertilize most of the year round.
So I guess it depends on what the tree is doing, what the weather is doing and where your tree is situated too.
Not sure if that makes sense or is the way of it, but maybe it helps

[austindrake]

If your plant has already gone into dormancy then it won’t be taking up anything through the roots, and fertilizing is largely wasted.

Yep, this makes perfect sense. On my deciduous trees, where it is more obvious, I would definitely stop once leaves have begun to fall off.
Does it help continuing right up until the colours begin to change, as the tender growth will not be affected the same way that it would in the snowier parts? Or should I stop long before that point?

What about on my evergreens/natives which dont drop their leaves? Would I just continue to fertilise year round but at half the frequency or even half the strength? Or both?

Unfortunately its quite hard to find these specific answers with general searching on the web.

[treeman]

No need to feed in winter at all but in autumn when the tree is beginning to ''withdraw sap'' it's a good idea to feed a reasonably low N feed such as
1-0.5-2 (or 10-5-20) Or you can just give a feed or two of potassium sulphate only. You can witness this sap withdrawal in such trees as the fruiting apricot and the Japanese maple which are best pruned at this stage (when about half the leaves have fallen) to avoid bleeding.

[shibui]

I keep feeding developing deciduous trees until the leaves start to turn. After that there's no point as the tree can't take up nutrients and can't use them either.
Evergreens, however, in our climate seem to be able to take up and use nutrients right through winter. Grant Bowie got a group of growers right round Aust to do some side by side trials a few years ago with black pines. You may be able to find the original thread here on Ausbonsai. The ones I used for the trial definitely grow stronger in spring following winter feeding. The question for me is not whether to feed evergreens in winter but how much?

[dansai]

And then of course what stage of development they are in. No point feeding right through autumn and winter to get strong growth on an old refined Japanese Black Pine. However, a Native being developed, that would continue to grow through winter in my climate, would benefit.

[austindrake]

And then of course what stage of development they are in. No point feeding right through autumn and winter to get strong growth on an old refined Japanese Black Pine.

Most definitely. For me at least, they are all in early development, all purchased as tubestock or nursery stock within the last 2 years and Im pushing for as much growth as possible for the next few years to get myself some fat trunks and some good roots / nebari.

[Stevie_B]

Same for me. I’m also still seeing back budding and shoots on my natives, but it’s minimum of 19 overnight here so I guess it doesn’t factor too much.

Although as the days shorten growth will slow down too I’m guessing?