hydrophobic yamadori soil

[NaoTK]

I've been collecting pines from old river beds and a lot of the trees are in bone dry hydrophobic sand and decayed duff. Water just beads off the stuff yet the pines are happy. I'm torn about whether to remove this native soil (and potentially damage the root mass) and put in pumice or hope the field soil will eventually wet. It rains non stop here but the soil is still dry.

Anyone use wetting agents on bonsai soil?

 

[Lorax7]

Have you tried watering by immersion to try to get past the hydrophobicity to fully wet the soil? I know that, for example, peat is hydrophobic if it’s ever allowed to dry out completely and can be difficult to wet again by ordinary watering technique because the water just beads up and rolls right off it. Immersion watering can wet the peat again and then ordinary watering technique can be used afterward as long as the peat is kept at least a little bit moist, never allowed to dry completely. Perhaps it would do the same for your hydrophobic yamadori soil.

 

[Potawatomi13]

Lorax7 makes exact suggestion I would have. Also may help to add several holes in substrate. However suggest good repot in Pumice come Spring. Also what kind of tree?

 

[Wires_Guy_wires]

I know there's some yucca extracts available that act as a surfactant. Bonsai Nut uses a type of surfactant destined for plant use.
I use a drop of dishwashing detergent sometimes, in about a bucket of water, very dilute amounts shouldn't hurt.

 

[Bnana]

Some soils are hydrophobic and stay hydrophobic after wetting. That is not solvable like with peat. There must be some water in the soil but it is really hard to keep trees alive in soils like that long term. I would replace it with proper bonsai soil at the end of the winter.

 

[Bonsai Nut]

Anyone use wetting agents on bonsai soil?

I've used wetting agents for herbicides and fungicides, but not for soil. Because they reduce the surface tension of water, in theory it should help with water penetration, but I have no personal experience with it in that application.

 

[leatherback]

Use warm (NOT HOT) water to re-wet dry soil.

That being said: i woudl certainly aim at getting this removed over a period of time.

 

[PonderingSage:]

I place collected trees in a wheel barrel full of water, when they are still bagged up from collection. Then let them sit for a day or two. It seems to help break up the native soil.

 

[NaoTK]

Thanks for the suggestions everyone. I would try the water immersion method if I could; one tree's grow box is way too large to immerse. I will try the warm water at first. One website recommended dilute agar agar solution. I don't think I should replace the soil anytime soon as the trees were just collected.

The trees are lodgepole, subalpine fir, and mountain hemlock

 

[Flowerhouse]

My yard soil is hydrophobic if all the organic matter is removed, and the wind here removes organics from the surface pretty quickly. When I put wood mulch around my plants that seems to break up the surface tension and allows water to enter the soil. Maybe try some mulch or moss on the surface of the grow box?

 

[bwaynef]

I bought "spreader sticker" as a wetting agent a while back from a better nursery. There are also water-wetter products, geared specifically toward the 420 crowd, with prettier, if suggestive, labels.

 

[River's Edge]

Thanks for the suggestions everyone. I would try the water immersion method if I could; one tree's grow box is way too large to immerse. I will try the warm water at first. One website recommended dilute agar agar solution. I don't think I should replace the soil anytime soon as the trees were just collected.

The trees are lodgepole, subalpine fir, and mountain hemlock

All species I am familiar with and collect. As long as the soil is free draining, just keep watering until they hold moisture on their own. This time of year their moisture needs are less and you should be fine. You are correct in not changing the soil any time soon unless you have the facility to tent for humidity and protect from frost. For fall collection the least amount of disturbance is best. Spring collection is a different story.
Just be sure the root ball do not end up with water sitting in the grow boxes or pots being used! They all grew up in the Pacific Northwest so will be accustomed to lots of rain and high humidity at this time of year. If you have any questions, PM me.
Best in Bonsai

 

[Wires_Guy_wires]

One website recommended dilute agar agar solution

Don't use agar for water penetration. If it dries, it'll form a film that's hard to remove, like caked up hair gel. And it'll become insoluble. I've had my fair share of agar mistakes in the lab, it boils over pretty easily after you take away the heat.

You can use agar to increase water content in meals and food stuff like gelatin can, but in liquid mixtures it's not a very useful substance.

 

[NOZZLE HEAD]

My preferred wetting agent is polysorbate, (tween 20) is very well documented in plant tissue culture to have virtually no phytotoxicity by itself.

 

[Shogun610]

Interesting that it’s hydrophobic , what is the cause of the phobicity ? Well then there must be something in the soil or the soil itself that is causing nonpolar affect. You simply have to make the charge in the soil to flip, so when you repot use a higher percentage of akadama normally used for collected conifers , higher cation exchange capacity w the clay. You wouldn’t want to use surfactant that would just encapsulate the soil if that’s your goal overtime that would work,
Could be an accumulation of the decomposed waxy coatings of leaf matter for this cause.

 

[NaoTK]

In this case it is the microstructure of the sand that is making it hydrophobic. It is the finest sand I have seen. But it doesnt fall out like free sand, its sort of a stiff clump full of fine roots so I dont want to rake it out. In the photo below you can see the top humus layer is wetted, but 1 inch below the sand is bone dry. It has been raining for days here.

I tried warm water, agar agar solution, mild soap and nothing worked. I ordered some of the tween 20. I've been manually chopsticking the sand and pouring water into the holes but its still not wetting.

 

[Lorax7]

Thanks for the suggestions everyone. I would try the water immersion method if I could; one tree's grow box is way too large to immerse.

I doubt it's too big to immerse with this: concrete mixing tub

Having one of these around is handy for other things as well. A lot of folks use them for repotting so the soil remains contained and they don't make a mess in their garage. I use them in the winter time in the basement to capture the runoff from watering my tropicals. I just put the whole plant stand inside the plastic tub.

 

[NaoTK]

I doubt it's too big to immerse with this: concrete mixing tub

Having one of these around is handy for other things as well. A lot of folks use them for repotting so the soil remains contained and they don't make a mess in their garage. I use them in the winter time in the basement to capture the runoff from watering my tropicals. I just put the whole plant stand inside the plastic tub.

I have some of those tubs its just....the largest subalpine fir is 3ft by 2ft and must weigh 150 pounds. The central trunk is 4ft tall but will be jinned to ~3ft.

 

[hemmy]

In this case it is the microstructure of the sand that is making it hydrophobic. It is the finest sand I have seen.

Interesting your mention on sand. I had seen this once on wetting agents and sand on golf courses. Unfortunately, I don’t have any insight on its uses in containers.

https://www.gcmonline.com/course/environment/news/wetting-agent-differences

Sounds like you need a cheap inflatable kiddie pool for the immersion.

 

[Potawatomi13]

one tree's grow box is way too large to immerse.

Possible to dig hole in ground? Lack of H2O cannot keep tree alive. Desperation time.