Repotting seedlings

ConorDash

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Hello,

I have 5 Wisteria seedlings, coming up to 2 years old now, they have just started showing signs of growth this year (always little anxious to see that first growth, my first seeds).

They are currently planted in good size containers but garden soil, heavy organic nursery soil.
I strongly believe they will thrive and grow much better in my standard bonsai soil mix, mostly medium sized clay molar, some small size and small ratio of pine bark.

But should I repot? In regards to their age, species, (timing is good right now). Are their roots are more fragile due to age? Should I wait?
My first experience growing from seed.

DSC_0225 by Conor Dashwood, on Flickr
DSC_0226 by Conor Dashwood, on Flickr

Any thoughts and opinions, greatly appreciated.
Thanks,
 

0soyoung

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Since you have five, why not repot two now, one sometime after the summer solstice, and leave two alone this year? Compare outcomes.
Of course, move them into your bonsai substrate of choice when you do repot.
 

ConorDash

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Hmm very good point.. or I’ll chicken out and repot 1 now :). Do you have any info on roots of seedlings, know if they need any unique care etc?
Thanks 0so
 

0soyoung

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No unique care. You will simply have fewer roots than you will find on a bigger plant, so keep the root pruning proportional. Just like a big plant, root pruning will make the roots ramify, which is what you want.

Be brave. Your horticultural naivete is only thing that is actually at risk.

If you prefer to do only one at a time, fine. I just offered an idea in response to your request (and just now, an opinion) - they are now yours to do with as you please. You are welcome. End of story.
 

Shibui

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Wisteria roots are bomb proof. you can cut as much as you are able and they will still laugh derisively at you and continue to grow. Bud burst is a great time to do root pruning for wisteria but can still be done well into growing in full leaf.
'Taproot' is the first and strongest root to grow in most species in order to access deeper moisture and nutrients. In many seedlings 9many species) there's a strong vertical root and few or no laterals in younger plants. lateral roots develop later. Even if you only have a single deep root you can cut with confidence with most seedlings. New roots will grow from around the cut wherever you do so. wisteria are particularly good at recovering after root pruning.
These are currently only small sticks so actually need almost no roots to survive at this time of year. Even if you cut all roots off and plant the tops as cuttings they will likely survive.

Are you aware that wisteria take many years to mature enough to flower?
Seedlings do have the advantage of thickened trunk base so have better basal trunk flare than cuttings but very slow to mature. I've had some flower after 7 years but my first attempt did not flower for 19 years (late frost killed the buds before they opened) then no more flowers for another 3 years. Now flowers well every year.
 

ConorDash

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Wisteria roots are bomb proof. you can cut as much as you are able and they will still laugh derisively at you and continue to grow. Bud burst is a great time to do root pruning for wisteria but can still be done well into growing in full leaf.
'Taproot' is the first and strongest root to grow in most species in order to access deeper moisture and nutrients. In many seedlings 9many species) there's a strong vertical root and few or no laterals in younger plants. lateral roots develop later. Even if you only have a single deep root you can cut with confidence with most seedlings. New roots will grow from around the cut wherever you do so. wisteria are particularly good at recovering after root pruning.
These are currently only small sticks so actually need almost no roots to survive at this time of year. Even if you cut all roots off and plant the tops as cuttings they will likely survive.

Are you aware that wisteria take many years to mature enough to flower?
Seedlings do have the advantage of thickened trunk base so have better basal trunk flare than cuttings but very slow to mature. I've had some flower after 7 years but my first attempt did not flower for 19 years (late frost killed the buds before they opened) then no more flowers for another 3 years. Now flowers well every year.
Hey! I hit the jackpot and found the right guy for the question aye.

Yes, aware of flowering time, it’s ok, not my aim with it. It’s also a Chinese wisteria so 12-15 year flowering time, longer than American. It’s ok.

I’ll repot 1 or 2 today or tomorrow, seems like best timing so I’ll go for it. One is planted in the ground so that’ll stay, see how it develops compared to potted ones.
I’m aware maybe my climate is maybe not as ideal as yours for wisteria? So I won’t take “bomb proof” for granted.
I’ll repot careful, I’ll just arrange roots in a more horizontal way if I can. I’m not interested in pruning any at the moment.
Thanks for your advice, I’ll no doubt bugyou with more questions sometime!
 

BonsaiNaga13

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Have you tried to take the root ball out of the pot and look at it? I've rescently repotted a few 1 year old seedlings and they already had roots circling the pot of about the same size as yours, they weren't wisteria though and I started them in bonsai soil but the tap root was definitely significant enough to need to be removed.
 

ConorDash

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Have you tried to take the root ball out of the pot and look at it? I've rescently repotted a few 1 year old seedlings and they already had roots circling the pot of about the same size as yours, they weren't wisteria though and I started them in bonsai soil but the tap root was definitely significant enough to need to be removed.
I’ve repotted 2 now. They could have stayed inthose pots, roots weren’t bad but they will do much better in the Bonsai mix.

Here's a well known article by Brent Walston.
https://www.evergreengardenworks.com/rootprsd.htm
I’ll read it now, thanks :)
 

0soyoung

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They could have stayed inthose pots,
They are currently planted in good size containers but garden soil, heavy organic nursery soil.
they will do much better in the Bonsai mix.
Brilliant!
So did you put them in bonsai mix?
The AFP of garden/potting soil is not so good. Small/medium landscape bark if far, far, superior - cheap and very available here.
 

ConorDash

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Brilliant!
So did you put them in bonsai mix?
The AFP of garden/potting soil is not so good. Small/medium landscape bark if far, far, superior - cheap and very available here.
Indeed I have put 2 in.
I am now using small ration of smaller sized molar clay granules, larger ratio of medium sized molar clay and some pine bark.
They did have a large thicker and longer tap root, I cut one back a little but maybe next year I’ll reduce more, when more confident.
I assume they’ll need repotting next year, I hope they fill their pot with roots by then!

I prefer inorganic over organic, hence my ratio of molar clay over bark, just my preference. I can understand if you disagree though :)
 

0soyoung

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I prefer inorganic over organic, hence my ratio of molar clay over bark, just my preference.
I prefer my inorganic substrate and put nothing else in it, and only bring up bark as an alternative that I sometimes use bark to grow things out. I use bark all the time to top dress my garden beds. Getting more only involves a 2 mile round trip for me. My inorganic substrate costs about double, but involves a 30 mile round trip. Further, commercial growers in my area use composted bark instead of 'dirt' and I've seen the results across many species - far superior to any garden soil, IMHO. Nevertheless, I will always use an inorganic substrate when I have enough on hand.
 

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