Safe to plant JBP above Main Water Supply Line Pipe?

I’ve had these 2 small niwaki JBPs since Dec 2018.
They were originally bought in 15gal pots, and are 4-5’ tall.
I re-potted them into large 28” wide oak wine barrels in Feb 2019; so, they’ve been in them for almost 2 years now.

I am not sure it the roots have filled up the entire barrel yet. So, the rootball may still be smaller than the large barrel/pot. Irdk. Hoping the rootballs are a little smaller though, so it’s easier to dig and plant.

Anyways, I’ve originally always been wanting to plant them into the ground (as niwaki).
I actually attempted to do this in Jan 2019; but I saw the main water supply pipe to the house, as I was digging the hole. Hence, why I put them into wine barrels instead; as I was unsure if it was safe to plant it above the main water supply pipe/line.

As you can see, the location is in a perfect area for a nice specimen tree/niwaki. But, the main water pipe is 20” right below in the middle (BLUE dotted line).

The main question is:
Is it safe and okay to plant a JBP above this water line??
Maybe with some kinda barrier to deflect the roots away? (I have several spare 1x1’ and also 2x2’ granite tiles)

I walked around the neighborhood to see other plant placements, and I def see that some neighbors (not all though), have pigmy date palms and large 20-30’ fan palms right above their main water supply line.
Also, my old, tall, upright eugenia (with maybe an 8” trunk and 30yo… it’s been there since the house was built) is also right above the main water supply line (RED arrow).

I did some Googling, and read about some trees to Avoid and also ones that are Suitable for planting over or close-to water pipes.
But, I couldn’t find anything for JBP, or even San Jose Juniper (I have an old potted SJ juniper too, and 11 cuttings/air-layers from it).

Here’s what I found:

Trees with aggressive roots and fast-growing trees:
Silver maple, poplars, rubber trees, ashes, Modesto ash, sycamore, oaks, willows, basswood, tuliptree, elms, birches, mulberry, figs, eucalyptus, beeches, black walnut, magnolia, holly shrubs, ivy.

Small deciduous trees, slow growing, non-aggressive or shallow roots:
Japanese maple, ilex, carolina buckthorn, quince, wintersweet, acoma crape myrtle, crabapple, hoptree, stewartia, weeping higan, Jolivette cherry, eastern redbud, dwarf dogwood, ginko

Small, slow growing evergreen, under 20’ max height:
Boxwood tree, Hurd manzanita, tea-oil, yennan camelia, Mediterranean fan palm, akupuka, variegatum Japanese privet, some osmanthus, photinia, cabbage palm, Awabuki sweet viburnum, weeping blue atlas cedar, Chinese & Japanese plum yews, fernspray cypress, slender hinoki cypress.

No mention of Japanese Black Pine though from the “Suitable” lists I am researching.

Is planting a JBP safe there?

What about a SJ Juniper as a possible alternative? (I really want a JBP there though!)

Any help greatly appreciated!


I’d guess it’s a matter of how conservative you are about keeping the area around the pipe clear. I wouldn’t expect trouble if you keep the tree relatively small (a full size pine can definitely cause problems), but if you need access to the pipe it will be trickier with the tree nearby.

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I’ve decided to just plant it (sometime soon, when I’m not procrastinating/being-lazy). Main reason - I’d rather do it sooner than later, as they’ll just get heavier. Also, I really dread the idea of re-potting these huge half-wine-barrels in the future, and I’d rather just have them in the ground and never have to deal with re-potting them ever again.

Now, the questions are…

I want to reduce the rootball so it is a little easier and lighter to plant (for things like lifting it in&out of the hole to adjust for height, positioning, etc.).

Is it safe to reduce the rootball back to the original, smaller 15gal pot size when I bought them? (the current half-wine-barrel is about 28-30gal I believe).

I don’t even know if the roots have filled the entire barrels yet (it’s been in them for almost 2 years) or if it is pot-bound.
I am guessing it isn’t pot-bound yet, as it’s only been 2 years and the barrels are quite big. Irdk though.

Also, timing (I’m in zone 10b, with no freezing winters)…
Is now/fall, or winter, or spring best to do this rootball-reduction by 50% and plant in ground?

Also, it still needs its’ annual momiage/old-needle-removal and reduction of new branch tips (bifurcation)…
Can I do this around the same time as the rootball-reduction and planting in ground?
Or, should I do the momiage/pruning a season before, or after, the rootball-reduction and planting?
Which to do first - momiage/pruning or rootball-reduction/planting?

I would suggest the normal fall routine, needle reduction and minor cutback is still fine in your location. Knowing that you plan on repotting should influence the amount of work you do now to stay on the cautionary side, but still progress in maintenance and development.
I would save the replant until February/March and take a couple of extra steps. Place a barrier over the pipe to prevent root encapsulation of the pipe. Perhaps a heavy scrap of pond liner or similar barrier. The other step would be reduce the root ball as little as possible to reduce the recovery time. Get someone to assist you with placement if the weight is difficult to manage. If you judge the hole depth and place loose fill in the hole initially, one can place a lighter plastic sheet or garbage bag around and under the root ball to manage shifting for position prior to finalizing placement. Then simply pull out the plastic sheet or remains of a garbage bag.
This process works well in reverse for collecting yamadori and handling the root balls with little damage.
Best of luck

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Thanks for the nice tips!

I was planning on maybe using granite tiles (I have plenty spare 1’x1’ and 2’x2’ tiles); but pond liner sounds nicer! Just gotta see if I can find scrap material of it now.

Also nice tip with plastic bag. I have 40-80 heavy-duty plastic bags I kept (from the rock/pebble landscape renovation I did 2 years ago).

It seems to be difficult to source/find “scrap” pieces of pond-liner. I really don’t wanna buy huge sheets of it just for this project, ha.

But, I just remembered, I do had a lot of scrap black ballistic military fabric that I used to patch a convertible top several years ago. It is 1680D Cordura nylon fabric, DWR water-repellent coated, very strong and tear/abrasion resistant, and meant for outdoor exterior, RV, marine, tarp, etc.

Do you think the ballistic fabric will work? Idk of roots will grow through/into it. But, I’m thinking it won’t grow through it… as it’s meant for outdoor applications (like my convertible top) and water-resistant.

Of course, I have spare weed/landscape-fabric too… but I already know roots will grow easily right through that, lol.

Hmm… or perhaps use those heavy-duty plastic bags I saved that I mentioned would also work as a barrier (they’re meant to hold 75lbs of rocks). I can cut them into a sheet.

Perhaps simply combine the two, use the fabric material on top of the tiles! That will limit roots running between tiles and assist with containing rootball if it becomes necessary to remove down the road. Would also suggest some coarser material on top of fabric to aid drainage at the base of the rootball. Compensate for that area being cut off to drain directly below. Perhaps taper off the drainage tiles and fabric to allow gravity to do its thing in support of your drainage. Higher in the middle, lower on the edges.
Lots of options, degree of detail up to you of course.
Have fun

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Hard part over, lol - moving them heavy af barrels, removing pines from barrel and reducing rootball (so it’s easier/actually-possible/manageable to plant).

Never wanna do this again, lol. F big pots. Never gonna mess with anything bigger than a 15gal pot ever again.
These half barrels actually felt heavier than the small 20-28” boulders I placed before.

At least I don’t need to worry about the barrels anymore. And I can sell them too.

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The 2nd pine…

Not sure if that white stuff is the JBP’s beneficial michorrizae, or root aphids. Anyone know?

2nd step - momiage and pruning (bifurcation tips) tomorrow and Sunday or Monday.

3rd step - planting in ground (perhaps next wknd).
Gonna be easier/doable now, now that the rootball is realistically manageable.
They’re still heavy though… I can hardly lift them 6”.

(pics are jumbled and not in order)

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Wow - quite a project!

The yellow stuff is some kind of fungus, not root aphids. I don’t see any reason to worry about it.

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One done, one more to go tomorrow.

I’m thinking the momiage and light pruning should help in less transpiration… the newly reduced rootballs might not be able to support all that previous foliage properly.

Another reason I did momiage and pruning now instead of wait until spring… because I don’t wanna be standing on the soil while pruning in spring if they’re already planted in the ground, as it might shift/move/damage the newly establishing roots.

Also, it is much easier to do in garage… instead of being outside for hours (like I usually do).

2nd one all done pruning & momiage. Guess it takes about 6-7hrs per tree (I always forget, since I only do it once per year).

At least I don’t need to do this again until Nov2021-Feb2022.

Would have been easier if I didn’t need to move the big barrels and re-pot the day before, lol.
I’ll continue with the planting next weekend or maybe Wednesday.

Gonna be harder outdoors in front-yard once planted (like last time I did this).
Kinda makes me reconsider and think about keeping them in pots (but smaller than half wine barrels of course), since it’s much easier to do momiage in garage. But, the JBP just doesn’t look like it’s part of the landscape when in a pot. Meh… I guess I’ll plant them.

The trees look nice thinned out!

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After a few years of having them now, and after 3 annual bifurcation-prunings and momiage… I noticed it finally has tertiary and even some quaternary branching… should have quinary ramification in a year! :smiley:

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Finally done.

I’ll continue with backyard plantings (smaller plants) maybe next wknd. Need a break lol.

(Photos are probably out of order due to batch ULing)

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