Japanese Black Pine Soil Recommendations for Texas (Zone 8B)

[Bone *sigh* Beginner]

Hello all! I've tried (and failed) several times with potting my JBP in various potting media here in hot, dry Austin TX and still haven't had much luck with keeping my JBP's alive through the hot summer. Granted, I've always been so excited when I've received my pre-bonsai JBP's (mostly all 3-years-old) in the mail, that I can hardly wait to repot them into bonsai soil (possibly too quickly in the late spring/summer), so that might be more of the reason for my failure(s) than the actual soil itself...

Any JBP enthusiasts in Zone 8B and/or Central Texas that can recommend a good soil medium that will drain, but still retain enough moisture during during 90+ days of 95-100F temps in summer with daily watering?

Thanks!

 

[Russ1]

Timing is key, except in Japan where they seem to get away with almost anytime.
I usually re-pot my pines in mid March to April 1st here because I've learned that in my climate we can get 90 deg days in May and I have lost pines if I re-pot after April 1st.
Try to look ahead at the weather at least a few weeks after you will re-pot so temps stay below 80 and hopefully not get too hot, for me that's 80+
They will need a good month of the right temps to recover. If I get a day or so that is too hot I now bring them into my basement under lights where it is cooler and temps are more stable.

Not too sure about soil where you are but I have always used 50% crushed granite, 25% Turface and 25% Pine Bark and on hot days have to water up to 3 times a day.
This year I got some 3 yr old JBPs and started using Lava, Pumice about 85% total for the last 2 and about 15% Pine Bark for all my pines, the pumice is well drained but also holds more water so you can water more but it won't stay soaking wet because the excess water just flows through. Also the finer the soil the less air space and more water that will stay in the soil.
I'm sure everyone has their own mix that will works.

 

[Bone *sigh* Beginner]

Great info! So repotting at a point where the weather can stay below 80F for a few weeks sounds like the key. I think I was repotting at a far-too-hot time of year (early summer) and my JBP’s never had a chance to recover. Thank you!

 

[crab apple]

repotting store bought JBP that are usually root bound in potting soil is an aquirerd skill, Some ppl claim you can bare root them but ill bet most can't. Research 1/2 bare rooting which is a slower process which also allows the plant to keep some of its benificial fungas. Usually pines are put in a dryer mix with less pine bark and more inorganics. All I know for sure is that if you just plop the compacted root ball in a pot with dissimular soil (inorganics), it will eventually fail.
I'm sure it's ovios my spell check doesn't work anymore.

 

[Wulfskaar]

Hi! I've been able to grow JBP from seed and keep them alive and well for 3 years now. Keep in mind that I don't have larger JBP, only 3 years old and younger.

Initially, I was told they love full sun. However, full sun in Japan is different than full sun in CA or TX. We just get a lot more days of full sun and dry heat than Japan does. My young trees seemed to get baked pretty quickly, especially on hot summer days.

I keep mine where they get morning to mid-day sun and then shade after that.

Soil-wise, I've just been using Bonsai Jack conifer mix and I water every 1-2 days depending on the weather. Sometimes they go a bit longer without water. https://www.bonsaijack.com/category/premixed-bonsai-soil/conifer-pine-juniper-bonsai-soil/
EDIT: I did add some reptibark to the mix last year, so maybe that helped (?).

I'm sure some may have differing opinions, but so far, so good for me.

 

[Maiden69]

Pictures of the tree that died and the media it was in will help in giving better advise. I still don't have a JBP in a pot, but they are inside rootpouch bags until they are pretty much root bound. I use 100% inorganic substrate for developing, Bonsai Jack Monto Clay, Bonsai Block, and pumice in a 1:1:1, which will be slightly wetter than the traditional akadama, lava, pumice at 1:1:1 since both Monto Clay and Bonsai Block retain more water than lava. I can water the tree 2-3 times a day in the summer under 100+ degrees without it waterlogging as it is a very free flowing mix vs using something organic like pine bark.

Also, pictures of the JBP you are receiving (or received) will be nice as well, I repot my JBP in March-April and never had a problem with them not skipping a beat. Young pines can take way more root work than older ones, but it all depends on the conditions of the root ball at the moment. Once you have them in a pot, you will need to check on them constantly until you get a fell on how much water they use and adjust your watering accordingly. The consensus is the JBP like it on the drier side, IDK, mine don't seem to complain about the excess water and they grow like weeds. I guess once in refinement it will be a different story though.

 

[hardtimes]

100% pumice was way too dry for my pines. they seem to enjoy quite a bit of organics in their mix, sifted peat moss or pine bark. most people prefer pine bark. shade cloth on the hottest days wouldnt hurt but they can take the full sun.

i havent tried this mix but theyre near me and have a lot of really great pines

Premium Mixed Bonsai Soil Blend with Mycorrhizae, Akadama, Lava Rock, DG, Mulch - Fine 22 lbs

premium bonsai soil mix, premium bonsai soil base, premium bonsai soil blend, premium soil, bonsai soil, handmade, premium, akadama, lava rock, scoria, mulch, decomposed granite, dg, ready to use, mycorrhizae, soil mix, soil blend, soil base

houseofbonsai.com

they have both akadama and compost in the mix

 

[Russ1]

Also when you have done considerable root pruning there are fewer roots to take up water so until new roots start to fill the pot you need to be more careful about how often you water, keep them damp but not wet, if that makes sense. I think in Japan they get away with a lot because there climate is very humid, at least compared to where I am... except for last summer when it was very humid almost all summer, I was able to root cuttings in a very short time that I could normally never do. Humidity is a big factory in how most plants respond. The problem here is that we can have days of high humidity like 80-90%+ and then a few days later be hot and very dry, humidity in the 30% range. When it's humid very little watering and when it's dry up to 3 times a day. Try finding a soil mix that works for that.
Just adjust your watering to the soil and if it's an issue adjust your soil mix at next re-potting. As Maiden69 said "young trees can take a lot more abuse than older trees".

I have a JBP in a 1/2 wine barrel for over 30 years, started from a 1 gal pot and is now about 6 feet tall in the pot and would be much, much taller if I didn't keep cutting it back. It's been in just garden soil and some sand mixed in. Some years it rains most of the summer so it's always wet, other years it's like 90 deg plus all summer and almost no rain and I have to soak it every few day.. It's been through a lot 105 deg to -10 deg, a couple times hurricane winds almost flipped it over.
I think trees would not have survived for millions of years if they were too picky.. Is it ideal, probably not .