Author Topic: Yet another soil thread  (Read 3535 times)

Peep

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Yet another soil thread
« on: February 19, 2023, 10:13:14 AM »
I try to do my own research but after using lava split/grit last time and this apparently being not the ideal choice for citrus, I wanted to make sure to make a good mix this time. Especially because I'll be repotting 50 or so plants.

What I have around at the moment is:
- Coarse perlite 2 - 6 mm 
- COMPO Bio Potting soil - Extra light (pic: bottom right)
- Pine bark mulch 10 - 25mm (pic: bottom left)
- Coco husk mulch - compressed blocks - (pic: top left)
- 100% Coco potting soil - compressed blocks - (pic: top right)





Pot sizes: 20 - 30 cm
Climate: Belgium
Winter: outdoors (wet)
Summer: hot rooftop
Rootstock: mostly Poncirus, few C4475

For the coco products I hear about a problem with salt. Some say it's fine, some say to rinse it with water, some say to rinse it with certain products... Is it worth the effort or better to use something else...

I'm only in my second year growing citrus so I hope I can get some advice from people with a little more experience :)

« Last Edit: February 19, 2023, 10:51:31 AM by Peep »

Millet

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Re: Yet another soil thread
« Reply #1 on: February 19, 2023, 01:40:34 PM »
The wood chips, coarse perlite and potting soil make a good useable 5-1-1 blend.  I have many container trees growing in such a blend, and they are all doing fine.  Also, about a year and a half ago I planted a lime tree in a 20 gallon container using a 50/50 blend of Turface MVP and peat moss.  This blend was first invented by Lazz several years ago..  Over the year and a half that the tree has been growing in it  has been EXCEPTIONAL..  It is a great mix, and has not shown one single problem, not even any  compaction.  It drains just as good now as it did on its first day. I really appreciate  all of i its .benefits.  I would point out over the last year and half, it has not broken down at all.  A great blend that I heartily suggest. Amazing.
« Last Edit: February 20, 2023, 11:15:55 AM by Millet »

nullzero

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Re: Yet another soil thread
« Reply #2 on: February 19, 2023, 02:34:24 PM »
I find citrus is not very sensitive to coir mixes, a good citrus rootstock should have decent salt tolerance.
Grow mainly fruits, vegetables, and herbs.

Peep

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Re: Yet another soil thread
« Reply #3 on: February 19, 2023, 07:19:35 PM »
The wood chips, coarse perlite and potting soil make a good useable 5-1-1 blend.  I have many container trees growing in such a blend, and they are all doing fine.  Also, about a year and a half ago I planted a lime tree in a 20 gallon container using a 50/50 blend of Turface MVP and peat moss.

I wish I could have gotten Turface, but that kind of product I couldn't seem to find unless buying 1m2 of it. Same for pumice. So I ended up with the perlite.

I'm afraid my pine bark mulch is too coarse. I used it in my previous mix and I have the problem that some plants are able to "wiggle" too much, the substrate seems too loose, they are not kept sturdy in their pots. I think maybe the mix is too coarse and it's not able to get in between all the roots when repotting.

This is what I made last time:

9 cups lava (5 cups fine lava 4-8mm and 4 cups coarse 5-15mm)
7 cups light potting soil
6 cups pine bark mulch (10 - 25mm)
1 cup sand

I liked using sand as well, but I'm afraid that it will wash down and not stay homogenous in the soil, does anyone have knowledge about that? I think it might be fine in regular soil, but because it is the goal to have airy soil, it seems the sand might be able to wash downwards.

I find citrus is not very sensitive to coir mixes, a good citrus rootstock should have decent salt tolerance.

I'm reading that it could be fine in smaller amounts, for example 30% coco in the mix, while 50+ percent could cause problems. But it's always guessing how high you can go unless you know how much salt is in the coco.


For example maybe I could do something like this:

25% perlite
35% light potting soil
10% pine bark
10% coco husk
20% coco coir

Still a little bit of pine bark, but not too much because it's coarse, the perlite will also help because it's smaller when compared to the lava I put in my previous soil. And using 30% coco might be fine without going through a whole treatment process. 


EDIT: Also any tips on what the maximum percentage of perlite to use could be? I'm also a bit worried that everything will tip over with a gust of wind :p
« Last Edit: February 19, 2023, 07:41:38 PM by Peep »

pagnr

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Re: Yet another soil thread
« Reply #4 on: February 20, 2023, 03:40:29 AM »
Most coir brands should have an analysis, Ec for salinity, cation exchange capacity and K Potassium levels.
Here is an analysis sheet for an Australian brand using Sri Lankan product.
http://www.cocopeat.com.au/technical/productAnalysis/pdf/TechnicalAnalysis2001.pdf

Different grades and different sources will give different readings, and the pre processing quality controls will also determine levels.
Many types are ready to use from the bag, other types will be a component of other mixes so the analysis effect will be diluted by the % coir used in the final mix.
Most pot mixes get leached by pre watering before planting, and compressed dry coir is often wetted up with plenty of water.

Most pot mixes or pot mix ingredients should also have a similar analysis, or a generic one for the component.
ie pine bark will have a typical range of analysis that can be used in place of getting an analysis every time.

citrange

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Re: Yet another soil thread
« Reply #5 on: February 20, 2023, 05:23:59 AM »
I used to incorporate coconut husk chips into my citrus growing medium. They work well and provide reasonable drainage but only for a couple of years. After that they break down and encourage root rot. I no longer use them.
The same applies to standard bark mulch. The bark chips sold as 'orchid bark' or 'reptile bark' are much harder and will last much longer.
You should investigate the availability of Danish Moler Clay in Belgium. It is a form of fired clay granules which can absorb moisture while providing excellent drainage, and is often used by bonsai enthhusiasts. It does not break down. Here in England it is expensive if bought directly for horticultural use but can be found much cheaper when sold for use as cat litter or oil-spill absorbant. I now use it as the major ingredient in my potted citrus mixes.

pagnr

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Re: Yet another soil thread
« Reply #6 on: February 20, 2023, 07:19:48 AM »
I found a similar problem with large coir husk chips. When Citrus seedling root grow thru the chip it causes rot on the root section in the chip. They hold too much water.

Peep

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Re: Yet another soil thread
« Reply #7 on: February 20, 2023, 08:11:05 AM »
Most coir brands should have an analysis, Ec for salinity, cation exchange capacity and K Potassium levels.

It's a cheap product/brand so there is no information. It's Ä1 per brick. Coco coir is not used very much here it seems, because I haven't found it it in home improvement or gardening stores. I think I will put it in a bucket with holes at the bottom and run a bit of water through it, that wouldn't take too much effort.

You should investigate the availability of Danish Moler Clay in Belgium. Here in England it is expensive if bought directly for horticultural use but can be found much cheaper when sold for use as cat litter or oil-spill absorbant.

I have looked at the kitty liter as well, Linda Moler is supposedly a brand that has the good stuff. It's about Ä12 for 20 liters, still much more expensive than my perlite, but the problem is that I would have to find it in a local store in my city and I'm not sure I will. I'll keep an eye out though. Having it shipped to me makes it too expensive.

I found a similar problem with large coir husk chips. When Citrus seedling root grow thru the chip it causes rot on the root section in the chip. They hold too much water.

Yes, I didn't look for it, so maybe it's my imagination, but I feel like I've seen some less healthy roots that went through pine bark as well. I think the pine bark holds less water (at least when not decomposed yet), but maybe it can still suffocate.

I'm currently thinking in the direction of something like this:

30% coarse perlite
30% light potting soil   
30% coco coir
10% sand

No pine bark or coco husk, this will also help it to get between all the roots. My plants are still small, if they were larger I think it would be less of a problem to use larger chunks of material.

I'm still a bit unsure about how much sand I can use, afraid it will not stay mixed and start to fill in pores in the soil. For the other ingredients I think I need to mix them up and then see how it feels and if I want to adjust the percentages.
« Last Edit: February 20, 2023, 08:12:43 AM by Peep »

fruitnut1944

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Re: Yet another soil thread
« Reply #8 on: February 20, 2023, 12:23:55 PM »
I think 30% coir and 30% potting soil will be too wet. I realize that getting a coarse mix in around the roots may be an issue. But a wet mix that soon becomes fine and water logged is worse. Maybe thin out the roots?

BorisR

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Re: Yet another soil thread
« Reply #9 on: February 20, 2023, 02:30:06 PM »
I think I will put it in a bucket with holes at the bottom and run a bit of water through it, that wouldn't take too much effort.
Flushing with clean water will not get rid of the problem. Coconut works as a sorbing material and sodium ions have come into contact with it. When you apply fertilizers, sodium will be released, being replaced by magnesium. There will be a slight sodium poisoning and magnesium deficiency.
It needs to be soaked in magnesium salts. Magnesium sulfate or magnesium nitrate will do.
Or you can do nothing, give more magnesium when feeding. But it's less controllable.

Peep

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Re: Yet another soil thread
« Reply #10 on: February 20, 2023, 03:37:56 PM »
I think 30% coir and 30% potting soil will be too wet. I realize that getting a coarse mix in around the roots may be an issue. But a wet mix that soon becomes fine and water logged is worse. Maybe thin out the roots?

Yes, this is the also the doubt I still had.

I read that for sand to not clog up the soil, it's most important that it's coarse (sharp and large). I can buy 0-4mm sand and maybe see if I can have and easy/quick way to seeve out the finest particles / dust. Then I can use more sand and go to something like this maybe:

30% perlite
25% light potting soil   
25% coco coir
20% sand

Or even less organic matter:

30% perlite
25% light potting soil   
20% coco coir
25% sand


Flushing with clean water will not get rid of the problem. Coconut works as a sorbing material and sodium ions have come into contact with it. When you apply fertilizers, sodium will be released, being replaced by magnesium. There will be a slight sodium poisoning and magnesium deficiency.
It needs to be soaked in magnesium salts. Magnesium sulfate or magnesium nitrate will do.
Or you can do nothing, give more magnesium when feeding. But it's less controllable.

I read about using epsom salt to soak it, which is easy enough to find, but people also say you need to add Calcium Nitrate as well, which seems more of a hassle to find. If epsom salt can do the trick I will do that.

BorisR

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Re: Yet another soil thread
« Reply #11 on: February 20, 2023, 04:13:34 PM »
I think magnesium alone should work too. It will bind to the coconut, and the more active sodium will pass into the solution. According to the concentration, probably 1-2 tablespoons of Epsom salt should be enough for 40 liters. Leave it overnight or for a day. Maybe someone will tell you more precisely.

Millet

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Re: Yet another soil thread
« Reply #12 on: February 20, 2023, 06:29:05 PM »
Most all coco distributors have already flushed the sodium out of the husks.  Coconut manufacturer's flush with calcium nitrate and water to rid the sodium.  Further, I totally agree with Citrange, that hard wood chips are much much better than husks.  I have used both wood chips and husks, wood chips last a lot longer.  Husks brake down into a texture similar to peat.  However, I have found that Turface MVP and Peat is far superiors as a medium for container citrus trees..
« Last Edit: February 23, 2023, 11:24:09 AM by Millet »

pagnr

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Re: Yet another soil thread
« Reply #13 on: February 21, 2023, 01:50:22 PM »
Making soil mixes is a lot like baking or cooking, following a recipe, measuring and proportions.
You can have great ingredients in the kitchen, but if the proportions aren't measured well and in balance to the others it won't work.
Similar to baking, soil mixes need a balance of moisture and air ( fluffyness ) like a sponge cake, not a dense mud cake like texture.
A chocolate sponge and a mud cake use fairly similar ingredients to achieve different results, by using different proportions of ingredients ( and technique ).

My point is that the % of each component in soil mixes is highly important, and how they fit together to balance air and water holding.
Also the size of the pot they are going into is important, as the same mix will behave differently in flat punnets or large pots.

1rainman

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Re: Yet another soil thread
« Reply #14 on: February 21, 2023, 08:00:49 PM »
Most of the sand where I live is sugar sand very small. Some larger particles but mostly small. It works well in a mix but over waterings it settles downward until.the roots are dense enough to hold it in place. I sprinkle some on the top of the dirt and it makes it's way down. But we also have a lot of small shells that are larger than the sand particles.

Citrus don't like mulch generally. But it also depends how hot it is and how much you water. If you have good drainage you will need to water more often. That's ideal, really good drainage let it dry between watering but in the hot summer probably water almost every day. If you are going to be gone for a long time you might need to add clay or something that will hold water. Otherwise perlite with a small amount of sand and compost is pretty good. The perlite floats upward and the sand downward.and the perlite is bigger. If it's not hot perlite can get soggy but in hot weather dries really fast. In Europe with cooler weather I would go heavier on sand and only a small amount of perlite perhaps. Though sand will make it heavy and perlite is light. Citrus grows in Florida in almost pure sand so it won't hurt it just moving the pots is more difficult with more weight. Even small rocks at the bottom of the pot can be good. There is no perfect soil because you have to consider the temperature how frequently watered etc. Just keep the dirt from staying wet for prolonged period because citrus doesn't like wet roots though they like a lot of water as long as they can dry between watering

Peep

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Re: Yet another soil thread
« Reply #15 on: February 22, 2023, 08:55:44 AM »
I think magnesium alone should work too. It will bind to the coconut, and the more active sodium will pass into the solution. According to the concentration, probably 1-2 tablespoons of Epsom salt should be enough for 40 liters. Leave it overnight or for a day. Maybe someone will tell you more precisely.

Nice, should be cheap and easy enough.

Most of the sand where I live is sugar sand very small. Some larger particles but mostly small. It works well in a mix but over waterings it settles downward until.the roots are dense enough to hold it in place. I sprinkle some on the top of the dirt and it makes it's way down. But we also have a lot of small shells that are larger than the sand particles.

From what I read the downside of small sand can be that it fills the air pockets in the soil and clogs everything up. So it still helps in the sense that the particles themselves don't soak up moisture, but it can downgrade the amount of air in the soil and also how quickly it drains.

Citrus don't like mulch generally. But it also depends how hot it is and how much you water. If you have good drainage you will need to water more often. That's ideal, really good drainage let it dry between watering but in the hot summer probably water almost every day. If you are going to be gone for a long time you might need to add clay or something that will hold water. Otherwise perlite with a small amount of sand and compost is pretty good. The perlite floats upward and the sand downward.and the perlite is bigger. If it's not hot perlite can get soggy but in hot weather dries really fast. In Europe with cooler weather I would go heavier on sand and only a small amount of perlite perhaps. Though sand will make it heavy and perlite is light. Citrus grows in Florida in almost pure sand so it won't hurt it just moving the pots is more difficult with more weight. Even small rocks at the bottom of the pot can be good. There is no perfect soil because you have to consider the temperature how frequently watered etc. Just keep the dirt from staying wet for prolonged period because citrus doesn't like wet roots though they like a lot of water as long as they can dry between watering

I don't want to have to water everyday, but I think the coco coir and potting soil can take care of that. I also want to influence this by using fairly large pots, then they hold more water, but using enough perlite and sand so that it can't get oversaturated or have a lack of air in the soil.
My plants are small though, so pots will be 20 - 35 cm I think. 

In summer it should still be possible to have it (almost) dry out once a week. In winter it will rarely or never dry out, even if using small pots, so I don't think using larger pots would change anything in winter. I think in that case it would actually be better to have larger pots with lower saturation point than small pots.

I don't like using rocks or anything at the bottom. I tried that at the beginning using some gravel, mostly to make the pots a bit heavier and also thinking it might help water to flow out of the holes at the bottom of the pots.  But what happened was that the citrus liked this thin layer of gravel and grew all it's roots there instead of in the soil. So when the weather started to become hotter, the plants had a lack of water because most of the roots had grown inside the layer of gravel, which didn't hold much water. And even with daily watering it would just cause the soil above it to stay wet and risk root rot. Because of this I prefer to make the substrate as homogenous as possible. Which also means I don't want sand to move to the lower half of the pot and perlite to move to the top half.


@Everyone

Some good information here in the topic, comments are still welcome of course, but I think I will have to experiment to really get further now. Buy a bag of sand and see how coarse it is, see if I can easily sift out the finest particles / dust. Will have to wait a few weeks before I have time for that unfortunately.

Maybe I'll start with something like this:
25% perlite
25% light potting soil   
25% coco coir
25% sand

And then start changing the percentages and see how the soil behaves.

Like @pagnr says it will be a bit like cooking. I suspect that the ideal mix will also depend on the exact type of sand, potting soil and coco coir. I imagine the type of sand and soil / coco coir can influence how they cling to each other, same for the perlite.  Which may influence how the amounts of each ingrediŽnt will have an effect on if the mix stays homogenous
« Last Edit: February 22, 2023, 09:00:30 AM by Peep »

1rainman

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Re: Yet another soil thread
« Reply #16 on: February 23, 2023, 06:15:46 AM »
Sand and perlite will stay pretty mixed. It's just a slow process over time it settles downward or upward. The roots then grow and hold it in place. But if I mix it I try to keep most perlite away from the top layer and most sand near the top then it settles and evens out. You will need to mix it in because regular compost will be too wet and too acidic generally. The sand and perlite being neutral.

You could grow in virtually pure sand or gravel it just lacks nutrients then compensate by fertilizing. With your mix over time the organic material will be consumed by the plant and it will become a higher percentage of sand and perlite over time . Usually you just add compost to the top and fertilizer but this is like years in the future.
« Last Edit: February 23, 2023, 06:18:37 AM by 1rainman »

Millet

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Re: Yet another soil thread
« Reply #17 on: February 23, 2023, 11:34:23 AM »
For a long time it was thought that adding rocks to the bottom of the container helped in drainage.  However, it is now known that adding rocks to the container's bottom raises the perched water table higher into the container,.

1rainman

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Re: Yet another soil thread
« Reply #18 on: February 23, 2023, 11:55:01 AM »
Plants have done well for me both with rocks and without but often without rocks when I remove the plant there's a soggy layer of soil at the bottom like swampy. With the rocks even if there's water at the bottom it's clean it has air it's not all rotten boggy like. But I'm in Florida now so it isn't a concern everything dries out pretty quickly in the heat but in a cool damp environment I would do rocks or sand.

25% perlite, sand, compost, husk is a good mix as long as you fertilize.

Millet

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Re: Yet another soil thread
« Reply #19 on: February 23, 2023, 12:06:49 PM »
1rainman the soggy layer at he bottom of a container IS the perched water table.  Every container has a perched water table.  Adding rocks to the bottom just causes the perched water able to be lifted higher into the container.
« Last Edit: February 23, 2023, 01:08:04 PM by Millet »

poncirsguy

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Re: Yet another soil thread
« Reply #20 on: February 23, 2023, 12:31:09 PM »
I put small rocks/ stones in the bottom of my pot followed by window screening. then potting mix.  This allowed oxygen from down undr and above to penatrait the soil.  The perched water table did not last long.

Millet

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Re: Yet another soil thread
« Reply #21 on: February 23, 2023, 01:10:22 PM »
The reason that the perched water table did not last long in poncirusguy's containers, is because he sucks it out with a vacuum cleaner.

Vegan Potato Man

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Re: Yet another soil thread
« Reply #22 on: February 24, 2023, 11:35:48 AM »
The reason that the perched water table did not last long in poncirusguy's containers, is because he sucks it out with a vacuum cleaner.

Are you sure that would work? My understanding is its very difficult to remove except by evaporation and transpiration.

poncirsguy

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Re: Yet another soil thread
« Reply #23 on: February 24, 2023, 12:04:16 PM »
The reason that the perched water table did not last long in poncirusguy's containers, is because he sucks it out with a vacuum cleaner.

Are you sure that would work? My understanding is its very difficult to remove except by evaporation and transpiration.
Yes  I get an extra quart or 2 of water with the vacuum after the the pot was done dip draining.

fruitnut1944

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Re: Yet another soil thread
« Reply #24 on: February 24, 2023, 12:43:46 PM »
A wick out of the bottom of the pot works like the vacuum. Something like an old sock stuffed into the bottom of the pot where the perched water will be. Then run that under the pot unto the soil below. It wicks the perched water down into the soil. No need to get out the vacuum every time you water.

 

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