Summer Repot of Flowering Quince?

[Clicio]

I have just repotted mine after a mite infestation.
It's the very beginning of the Spring here, but temperatures are already consistently above 30ºC/80f.
In less than a week it has grown a lot of new leaves and as the old soil was already a good draining bonsai soil, I have reused about 30% of it.
It is thriving. @0soyoung they grow very fast at around this temperature, once you provide them with gallons of water every (dry) day.

 

[roberthu]

Take it in steps. First remove the nursery soil and get it into your chosen substrate.
Start by knocking off the plastic nursery pot. Cut off the bottom third to half of the plug. Then wash and/or gently comb the roots to get rid of the soil. Then do as I described, using the nursery pot it was in. If (based on experience) this seems like removing far too much root, find and larger diameter pot.

If reusing the nursery pot it came in, you should fill the bottom 2/3rds or so with bonsai substrate and put your plant on top and cover the roots with substrate. But I've glossed over two problems.

1. substrate will just pour right out the nursery pot drain holes
   1. I put a bit of sphagnum or green moss in the drain holes
   2. OR a big piece of screen that will cover the bottom of the pot and all the drain holes
2. the plant is not constrained in the pot
   1. I thread a long piece of wire through one or two drain holes, bending the end up on the outside of the pot, then place the plant and feed the wire down the other side and out an opposite drain hole, pulling to secure the tree and again bending the end up on the outside.
   2. secure the trunk/branches with guys to the pot rim so that it won't move when the pot is jostled.

Trees grow as the temperature increases up to about 95F/35C. The rate of photosynthesis is and remains maxed out, but the other metabolic processes continue to increase with temperature, so the tree doesn't grow - it burns carbon faster than it can be fixed. Other and deleterious effects occur above this temperature - certainly by 115F/40C tissues are dying. Conversely, even though you may feel uncomfortable, trees are growing fast and thriving at temperatures below 95F/35C. Below 40F/5C metabolic activity is very very low, and there is virtually no growth.

The issue with 'heat waves' is that they arise because of the incursion of a dry air mass. Like my climate, the relative humidity (rH) of yours rarely drops below 50%. When you had the heat wave, it dropped as low as 30% or so when the temperature of the day maxed-out in the afternoons. I went over this in some detail years ago - maybe reading through one such old post will help you to understand, if you want to take the dive.

Awesome thanks!
The quinces are actually in turface and lava mix so the roots should be easy to comb. I will be careful not remove too much roots if not have to and pot in pure akadama for fine root development.

 

[0soyoung]

Oh, @roberthu, I forgot to say that after a year, move it down a pot size after a year in substrate, basically following the same procedure, though you can be more aggressive about root pruning once you've got a goodly amount of root ramification and root pad development.

in pure akadama for fine root development.

I think that hard particles are better for root ramification. My scientific basis for this is a paper I've cited at least twice recently: "Root System Architecture from Coupling Cell Shape to Auxin Transport"

 

[roberthu]

Oh, @roberthu, I forgot to say that after a year, move it down a pot size after a year in substrate, basically following the same procedure, though you can be more aggressive about root pruning once you've got a goodly amount of root ramification and root pad development.

I think that hard particles are better for root ramification. My scientific basis for this is a paper I've cited at least twice recently: "Root System Architecture from Coupling Cell Shape to Auxin Transport"

That is a hell of a read.... Thank you! I will save it for scotch time. Alcohol usually helps when I am lost.

 

[Driftwood]

Take it in steps. First remove the nursery soil and get it into your chosen substrate.
Start by knocking off the plastic nursery pot. Cut off the bottom third to half of the plug. Then wash and/or gently comb the roots to get rid of the soil. Then do as I described, using the nursery pot it was in. If (based on experience) this seems like removing far too much root, find and larger diameter pot.

If reusing the nursery pot it came in, you should fill the bottom 2/3rds or so with bonsai substrate and put your plant on top and cover the roots with substrate. But I've glossed over two problems.

1. substrate will just pour right out the nursery pot drain holes
   1. I put a bit of sphagnum or green moss in the drain holes
   2. OR a big piece of screen that will cover the bottom of the pot and all the drain holes
2. the plant is not constrained in the pot
   1. I thread a long piece of wire through one or two drain holes, bending the end up on the outside of the pot, then place the plant and feed the wire down the other side and out an opposite drain hole, pulling to secure the tree and again bending the end up on the outside.
   2. secure the trunk/branches with guys to the pot rim so that it won't move when the pot is jostled.

Trees grow as the temperature increases up to about 95F/35C. The rate of photosynthesis is and remains maxed out, but the other metabolic processes continue to increase with temperature, so the tree doesn't grow - it burns carbon faster than it can be fixed. Other and deleterious effects occur above this temperature - certainly by 115F/40C tissues are dying. Conversely, even though you may feel uncomfortable, trees are growing fast and thriving at temperatures below 95F/35C. Below 40F/5C metabolic activity is very very low, and there is virtually no growth.

The issue with 'heat waves' is that they arise because of the incursion of a dry air mass. Like my climate, the relative humidity (rH) of yours rarely drops below 50%. When you had the heat wave, it dropped as low as 30% or so when the temperature of the day maxed-out in the afternoons. I went over this in some detail years ago - maybe reading through one such old post will help you to understand, if you want to take the dive.

Please forgive me but I am a simple-minded person with a limited technical language, so is it ok to repot any month as long as there is a constant temperature between 95F/35C and 40F/5C? Does daylight length affect this process? Does heat waves brinks lower humidity levels and how it's affect the growth and repotting issue?

I have just repotted mine after a mite infestation.
It's the very beginning of the Spring here, but temperatures are already consistently above 30ºC/80f.
In less than a week it has grown a lot of new leaves and as the old soil was already a good draining bonsai soil, I have reused about 30% of it.
It is thriving. @0soyoung they grow very fast at around this temperature, once you provide them with gallons of water every (dry) day.

I am glad things are going all right for you in this case but the only reason I decided to repot my chaenomeles in late summer or early autumn is because of some comments by professionals about reducing the risk of root nematodes? Perhaps Osoyoung can shine a light on this.

 

[0soyoung]

I will save it for scotch time. Alcohol usually helps when I am lost.

Cheers!
I too like Scotch and more so, Japanese whiskeys.

 

[0soyoung]

Please forgive me but I am a simple-minded person with a limited technical language, so is it ok to repot any month as long as there is a constant temperature between 95F/35C and 40F/5C? Does daylight length affect this process? Does heat waves brinks lower humidity levels and how it's affect the growth and repotting issue?

Yes, day length has an effect.

In simple bullet points

• Plants grow only when (maybe varying) temperatures are in the range
  • above roughly 40F/5C
  • below 95F/35C
  • growth depends upon carbon being fixed = photosynthesis
    • for most tree species used in bonsai, this happens only during the daytime
• Plants generally have a high capacity for root growth following the passage of the summer solstice (21 June in the northern hemisphere, 21 Dec in the southern).
• Repotting damages roots and reduces their capacity adsorb water.
• Not just anytime. NOT when new growth is extending above ground.
• Dry air pulls water out of the tree, predominantly through the leaves.
• relative humidity is lowest in the afternoon, the hottest part of the day, lowest at night
• Waxy-leaved plants do a good job of limiting water loss by closing their stomata.
  • Pines and elms are examples of waxy leaved trees
  • Maples are NOT waxy-leaved.

Often, our daily weather is due to a large mass of air in the area. It contains a certain amount of moisture defined by the dew point. At the dew point temperature the relative humidity is 100% and water condenses on anything just a smidge colder. Solar radiation heats the air and the relative humidty drops correspondingly. A local 'heat wave' occurs because a new drier air mass has moved in.

 

[Clicio]

...the only reason I decided to repot my chaenomeles in late summer or early autumn is because of some comments by professionals about reducing the risk of root nematodes?

Nematodes don't fly.
In fact, they can move a little in the ground, so if your plant is in direct contact with the ground, it can happen.
In my case going from old bonsai uninfected soil to new bonsai "clean" soil makes it pretty safe, nematodes wise. And my bonsai are up in benches.
So, I repot my quinces in the Spring. If you want to feel safer, do it in the Fall.