Do I need to repot my japanese black pine?

[clabor93]

Hello everyone,

I'm from Italy. A few days ago I bought a Japanese black pine bonsai. As you can see on attached video and photos, the soil seems to be too much compact. The seller told me that I do not have to repot this year since it has been repotted last year.
In your opinion is it true? If yes, which is the appropriate shape and size of the new pot? When to repot and if the soil in the attached picture is appropriate for it.

Here is the video where I show my bonsai soil:
https://gofile.io/?c=4JFnrn

If you have time and patience please read below for additional questions.

Which type of fertiliser is suited? When to use it?
Same story for the insecticide.

Please take in mind my bonsai is exposed to the outside climate described in details.

Winter: Temperature usually 8°C-15°C (45°F-60°F) Mild/humid/rain alternating with sunny/dry/cold. Snow very unlikely.
Fall: 1st part Temperature usually 15°C-25°C (60°F-77°F) Days similar to summer but shorter and colder
2nd part Temperature usually 10°C-20°C (50°F-70°F) Humid/rainy sometimes thunderstorms and windy
Spring: Temperature usually 10°C-20°C (50°F-70°F) Rain becoming rarer and mostly sunny days
Summer: Temperature usually 18°C-30°C (65°F-85°F) Sunny/hot usually windy in the afternoon.

Thank you so much for the attention

 

[MrWunderful]

Does water percolate easily through soil?

 

[clabor93]

Does water percolate easily through soil?

No it’s almost waterproof as shown in the linked video

 

[Mayank]

The video is helpful. Certainly the water seems to stay at the surface for quite a while. I'd be tempted to say that it needs to be repotted.

 

[clabor93]

The video is helpful. Certainly the water seems to stay at the surface for quite a while. I'd be tempted to say that it needs to be repotted.

Thank you for your time and support

 

[bwaynef]

If this were mine, I'd definitely half-bareroot it to start replacing the soil in this tree. When you repot it, get rid of the mound that's in place as well. (Notice how the water runs down to the edge of the pot? Its because it's mounded (...and the soil/moss has become hydrophobic).)

 

[MrWunderful]

No it’s almost waterproof as shown in the linked video

I didnt watch the video. But the easy answer is, yes if water does not percolate then the tree needs to be repotted.

 

[WNC Bonsai]

The soil does look crappy (non-technical American slang for bad). I would repot if for no other reason than so I would know what it is and what to expect for drainage and water/nutrient retention. Although I am only into my second year with a similar looking black pine what I have read and seen suggests these like things a little wetter than most pines so take that into consideration when deciding on a final mix. You may want a little more akadama than usual for other pines.

 

[Stan Kengai]

Your tree looks healthy. Try cleaning the soil surface before considering repotting. Remove the first cm of old soil and duff. If there are few or no roots on the top once the first layer is removed, loosen that next layer of soil. Water well. Wait several hours, and then see how the water percolates the remaining soil. If it still does not drain quickly, or if the soil just beneath the surface is full of roots, it is time to repot. If it does drain, simply refill with new soil. No repotting is necessary.

 

[Shibui]

I am always in favour of getting trees into a known mix as soon as possible. having lots of trees in different unknown potting mix causes problems with watering and care as you need to learn to water each one differently. Trees in known mix can all be watered and cared for in a similar manner = more success.
We have a similar climate (slightly cooler in winter and hotter in summer) and I have found that black pines do not object to more regular root pruning so I believe it will be safe for you to repot this spring.

 

[Wires_Guy_wires]

If all else fails and you're not sure what to do: go to the local tackle shop, bait store or whatever those worm-selling stores are called.. And get yourself a can of worms and release them in the soil.
They'll worm their way through the soil, and their tunnels will provide ample percolation for the time being.