Soil for ground growing raised bed?

[Lars Grimm]

Hi All,

I am planning on building a small raised bed (4'x8') to put some new stock into the ground to thicken up. My native soil is very clay heavy, so I'll be buying soil components to mix together to fill the bed. Does anyone have any recommendations for what mix to use? I'll be putting mostly maples (japanese, trident, amur) into the bed.

Thanks,
Lars

 

[Cypress187]

Subscribed to threat (wait it's called a thread ), i would also like to know. I guess soil that leaves room for airand root development (perlite / lava rock?) , maybe some organic componentsfor food (pine-bark / sphagnum?) . This is speculation, in this video they explain their mix (she has really hairy hands btw. very funny If you like it you should also watch this).

 

[GrimLore]

I have had raised beds at our old place and a friend here has had success mid-state using the following without breaking the bank. We have done simple 4'x'8' boxes of Pine shelving 8 and 12 inches deep. We light sand, weather coat it, and simply screw them together in place using Zinc coated or stainless screws.

1) Make certain there is drainage at the lowest end. Even a 1/2 inch will prevent it from becoming water filled.
2) If you have voles loose rack a coat of PermaTil - very loose, 1 bag at the most(it seems like it would not work but it does for various reasons)
3) We mix top soil and Kiln dried horse bedding(coarse), go heavy on the horse bedding as it is inexpensive and holds up a LONG time. keep raking as you are filling.

The whole thing is quite simple an inexpensive that way and provides you with a nice loose semi organic mix.

Grimmy

 

[Dav4]

I've got raised beds for veggie growing and bonsai stock just south of you in N GA...I feel your pain. Honestly, most of my beds have been made from home made compost, horse manure/shavings and soil conditioner mixed in to the native soil. The clay soil is actually pretty nutrient rich and moisture retentive once you've broken it up and mixed in the organics. You can probably find the composted horse manure nearby. Good luck, as it's a lot of work. Well, it was for me, but I've got hundreds of square feet of raised beds I've been working for the last few years...you should be able to work yours in a few hours.

 

[Brian Van Fleet]

Here, we have a chopped pine bark sold as Soil Conditioner. That and Turface, along with sifted fines from my regular soil always found its way to my growing beds.

 

[Bunjeh]

I did the same thing last year and just ammended the soil I had. Final mix included soil, sand, bark and pumice. Everything is doing well.

 

[armetisius]

Lars,
As this smacks of all the makings for another "soil wars" episode ?, I will not comment on composition.
But I will give you some observations that I have noticed with raised beds. They do tend to become overly
wet if not "pitched" slightly to one end to aid in drainage [as GrimLore pointed out]; and they do need to be
very open/loose in their composition for the same reason and to keep the soil aerated; they also must have
a good nutritional retention factor to them but watch for phosphorus build up --soil test annually-- which
can harm your plants if it becomes too high; establish a "green-free" zone around it--bermuda grass runs
through one faster than a wild fire through November broom sedge--always mow the surrounding area
with the effluent blowing AWAY from the bed and it cuts down on weeds/grasses getting started.
Just some thoughts on the matter--Good luck

 

[Eric Group]

The only soil allowed for Bonsai in any state or level of development is 100% Akadama! You should be able to get a pallet shipped from Japan that will fill a decent sized grow bed and I bet it wouldn't cost more than about $20,000 for the shipping container (plus the cost of the Akadama, you prolly stay below $30k!)! The trees won't grow any faster than they would in dirt, but at least you would have the satisfaction of knowing you are doing it right!

 

[M. Frary]

The trees won't grow any faster than they would in dirt,

Probably slower. All that clay turning to goo.
I may try ground growing. Got a nice spot. I am going to actually use the ground. You know just dig a hole,toss in a tree,backfill and walk away. Novel idea,I know. Hope it works. Somehow the trees that live here grow in it. Imagine that.

 

[Eric Group]

Joking of course..

I used discarded potting soils from trees being bare rooted and sized down to smaller pots, compost and top soil- worked great and two out of the three ingredients were virtually free!

 

[Eric Group]

Lars,
As this smacks of all the makings for another "soil wars" episode ?, I will not comment on composition.
But I will give you some observations that I have noticed with raised beds. They do tend to become overly
wet if not "pitched" slightly to one end to aid in drainage [as GrimLore pointed out]; and they do need to be
very open/loose in their composition for the same reason and to keep the soil aerated; they also must have
a good nutritional retention factor to them but watch for phosphorus build up --soil test annually-- which
can harm your plants if it becomes too high; establish a "green-free" zone around it--bermuda grass runs
through one faster than a wild fire through November broom sedge--always mow the surrounding area
with the effluent blowing AWAY from the bed and it cuts down on weeds/grasses getting started.
Just some thoughts on the matter--Good luck

Another note on surrounding plant life- if you make a nice raised bed with good soil.. All surrounding trees and plants will send their roots searching for the increased nutrients found in the grow bed and fill it slam up pretty fast with roots if you do not creat a barrier below it, at the very least some landscape cloth can help prevent this for a year or two...

 

[GrimLore]

Another note on surrounding plant life- if you make a nice raised bed with good soil.. All surrounding trees and plants will send their roots searching for the increased nutrients found in the grow bed and fill it slam up pretty fast with roots if you do not creat a barrier below it, at the very least some landscape cloth can help prevent this for a year or two...

If his soil is virtually solid clay as it is here any liner will create a swimming pool including landscape cloth - I know. The beds I referred to are 8 and 12 inch deep and nothing grows up through the clay and then up another foot through the substrate. What does happen as with ANY type soil or mulch is that seeds will find their way to the surface via wind, birds, and squirrels. Our tiny front garden needs sprayed/pulled and it is covered with deep mulch as everything grows at the surface from unwanted seed... Now I can only guess you are referring to a shallow grow bed and not on clay?

Grimmy

 

[armetisius]

The only soil allowed for Bonsai in any state or level of development is 100% Akadama! You should be able to get a pallet shipped from Japan that will fill a decent sized grow bed and I bet it wouldn't cost more than about $20,000 for the shipping container (plus the cost of the Akadama, you prolly stay below $30k!)! The trees won't grow any faster than they would in dirt, but at least you would have the satisfaction of knowing you are doing it right!

If you are just hell bent on fired clay search out a manufacturing brickyard;
offer to buy their "breaks" and grog.Can usually be had by the truck load and
much more cheaply.Fired clay is fired clay and the brick leavings will hold up
a lot longer to more extreme freeze/thaw cycles. Though I personally think it
would be a waste of time, energy & money.
Enough of this nonsense.
You buy fat ass trunks from nurseries all the time. I have never seen a nursery
plant grown in aka-damn-[y]a and doubt I ever will. Learn to care for your plants
by learning to water and you won't need the idiot proof media. Yes it makes a
difference when they are moved to the development phase of bonsai but for growing out?
Waste of money.
IMHO.
(Cue the pile on of screamers)
Better wear your parachutes though; I won't be here
for your landings/to break your falls.
Going nursery shopping myself.

 

[GrimLore]

Joking of course.. I used discarded potting soils from trees being bare rooted and sized down to smaller pots, compost and top soil- worked great and two out of the three ingredients were virtually free!

Someone missed that one!

Enough of this nonsense.

But you told me everything you grow is in Akadama and you had the entire property filled with it 2 foot right over the top of the existing Come to think of it you never did answer me when I asked how the John Deere handles when you cut the lawn...

Grimmy

 

[Eric Group]

If his soil is virtually solid clay as it is here any liner will create a swimming pool including landscape cloth - I know. The beds I referred to are 8 and 12 inch deep and nothing grows up through the clay and then up another foot through the substrate. What does happen as with ANY type soil or mulch is that seeds will find their way to the surface via wind, birds, and squirrels. Our tiny front garden needs sprayed/pulled and it is covered with deep mulch as everything grows at the surface from unwanted seed... Now I can only guess you are referring to a shallow grow bed and not on clay?

Grimmy

Well, my yard "soil" is more of a hard packed sand with a really light colored clay underneath, but I have tried grow beds both ways- with and without landscape cloth under them and the one that had none under it got infested with roots from surrounding trees very quickly! The other has not had any drainage issues, but it is kind at the top of a little high spot in my front yard, so all sides slope away from the center and that may help it drain...

The "grow bed" I have had he most baffling results with has been my vegetable garden ( which somehow wound up with 4-5 permanent resident from my developing Bonsai family stuck in between the rows of veggies!).. The first years it would grow practically nothing but collards... I was maki my own compost and adding it as fast as I could produce it but that didn't do much... The following year I basically made the whole garden a raised bed by applying a pickup truck load of compost I bought from a local landscaping store- mixed it with some bagged compost "Earth food" I think it was called- and had better results THAT year the next year- last year I expected even better results... Annnnnd had the worst veggie garden ever! A small rabbit had a hand in that of course... So, now I have a dog, no more rabbits in the yard, and he is pretty good (PRETTY good) about not messing with my plants... I cut the garden short early Spring of last year, more lched a crop of beans down into the soil, mad three + BIG loads of compost I have been mixing into the dirt for almost a full year with nothing growing in most of the garden... I expect a big cropof veggies! Kind of an aside I guess... But still sort of on topic, because what I am getting at is over using the soil! Every year you have a small garden/ bed planted, the plants leach nutrients form the soil! So, if you do not let it rest long enough between plantings, your ground can quickly become barren. Not an issue for trees in the wild as they just keep sending out roots deeper, wider... To find nutrients button in a smaller area- even on a large farm- it can be a problem! So, you need to replenish soil frequently and add nutrients and let the soil rest and replenish between planting to keep getting a consistent crop yield... I know this should be applicable to Bonsai as well when growing them out, and how you take this advice and apply it to your situations is up to all of you! I am just passing on some of that "country boy" wisdom about "crops n such" gleaned from decades of living around farmers and master gardeners...

If you are just hell bent on fired clay search out a manufacturing brickyard;
offer to buy their "breaks" and grog.Can usually be had by the truck load and
much more cheaply.Fired clay is fired clay and the brick leavings will hold up
a lot longer to more extreme freeze/thaw cycles. Though I personally think it
would be a waste of time, energy & money.
Enough of this nonsense.
You buy fat ass trunks from nurseries all the time. I have never seen a nursery
plant grown in aka-damn-[y]a and doubt I ever will. Learn to care for your plants
by learning to water and you won't need the idiot proof media. Yes it makes a
difference when they are moved to the development phase of bonsai but for growing out?
Waste of money.
IMHO.
(Cue the pile on of screamers)
Better wear your parachutes though; I won't be here
for your landings/to break your falls.
Going nursery shopping myself.

Yeah.... I was actually just kidding around there Armestisious... Thought it was pretty clear when I told someone to import $30,000 worth of soil to grow out a couple trees AND said it wouldn't make them Grow faster, that I might have been joking....
In case you or anyone else did not realize that- please do not go fill a whole grow bed with Akadama! I would hate to be the one to convince someone to cash in a retirement fund to fill their grow beds!

 

[GrimLore]

But still sort of on topic, because what I am getting at is over using the soil! Every year you have a small garden/ bed planted, the plants leach nutrients form the soil! So, if you do not let it rest long enough between plantings, your ground can quickly become barren.

That is exactly why I use little soil in a grow bed. With the addition of a large amount of kiln dried pine( very inexpensive) unlike soil conditioner. A 5ish USD bag of this stuff will 1/2 fill a 4'x8' bed - they sack blows up to a huge amount. As long as it all drains well over the clay base all works "simple" as it should.

In case you or anyone else did not realize that- please do not go fill a whole grow bed with Akadama!

No worries man - happens more often then we like and I myself am happy to get it clarified before it turned into a battle of sorts

Grimmy

 

[armetisius]

@Eric Group , @GrimLore @everybody else who may have been offended
I have re-read my posts of earlier today and still feel the same. It was not
directed at either of you personally and probably would not have occurred
at all if I had not looked up and realized that the OP had a big old total of
--hold your breath--11 posts. I am, however, sorry that it came off as
directed towards either of you or your posts because it was not intended to.
I respect both of you as people and as growers. But I have just reached my
point of frustration with "can you tell me how to pick my belly button because
I am too lazy to do any research/reading of my own. Why should you? because
I asked." NO. If you have a legitimate question about something that needs
clarifying that is one thing. BUT when it obvious that you haven't even tried
to find out anything about it yourself--p.o. We all spend time weekly answering
inane questions that have been discussed previously--some so may times they
are legendary i.e. soils-- and have no time to discuss anything of value anymore.

I took your post about a bed of akadama as the humor it was and thought mine
would have been obviously a "one up" on the ridiculous scale. Brick would require
welding gloves to protect your hands for even weeding. Not to mention the goggles
you would need as well if you used a cultivating tool. Right about there is when I
realized we had all chimed in without one bit of interaction from the OP and
frustration slapped me. I stated something I thought would kick start some shyte;
through in a brag over the fact that I can still find an open nursery down here, and
walked off. Sorry that it came off so acrimonious.

PS: Grimmy, you know what my soil is like here. It is akadama--hard pan version
but akadama "waiting to happen" none the less. And if I did have the entire property
covered in the stuff I would go broke adding in something I could actively grow in.
The water required would be prohibitive to begin with not to mention the ferts.
Good joke though; especially as many times as you have heard me cuss my soil
(actually lack of) here.

PPS: Did find some cool stuff today though. Love me some "penny acre lot" plant
shopping. Hands itching like crazy and not from handling to many needle form
junipers. Got back too late to even unload before dark.

 

[Andrew Robson]

Pumice would be my top choice. For a grow bed to strictly thicken up trunks, I would probably use a mix of 50% pumice, 25% decomposed pine park, and 25% of other organic mixes.

Cheers!

 

[vaibatron]

Chefs table w/ Dan Barber- taught me a great deal about rotation of crops and the health of soil .. Check it!

 

[Lars Grimm]

Thank you all for the very helpful advice. I am fortunate that I have several other raised beds in the area and have recently cleared out some smaller trees so I shouldn't have too much competition from surrounding trees/bushes. Based on the recommendations, I'll have to see what material can be purchased in large enough quantities at cheap enough prices.

@armetisius I thank you for your first post. The issues of regular soil tests and a green free zone are a very helpful insight. I had not found that information in my extensive online search for additional information on growing bonsai stock in raised beds over a clay base. It is very helpful that individuals like yourself are willing to give feedback on posts in the "New to Bonsai" forum for those of us with less than 357 posts besides our name.