Container Mix...mix your own

Ed of Somis · March 22, 2014

I have been studying what makes a good container mix...and there sure are many recipes! One thing is critical: drainage. Having a container that is muck on the bottom 4 inches smothers the plant and leads to death. Some people think putting gravel, glass, or even broken pottery around the holes helps. It is not true (seems like it should help...huh?). I will not get into the details and science behind why this happens...just know it does. We all have pulled out "mucky" plants that were dying....right? Creating a mix that is "free draining" simply involves eliminating small particles that plug up the mix. Adding larger particles like perlite, pine bark, gravel, etc....does not help a mix with small particles (like garden soil). How many bb's does it take to make pudding drain??? You get it....right? Adding a wick that is in the bottom of the mix and extends out the bottom hole is a great answer. Simply explained...the cohesive tension shared by the wick and the mix "fools" the mix into "thinking" the pot is deeper. Thus, perched water continues to drain. Not the scientific explanation...but you get it.
Today I planted many containers for my tomatoes using differing amounts of: pine bark (orchid bark), perlite, compost, amend, peat moss, and palm/cactus potting mix. I wicked most of my pots, as well.
Whatever you do...do not use MiracleGro "Moisture Control". It makes the muck factor worse (maybe for hanging baskets I suppose). Happy Spring!

rnewste · March 22, 2014

Ed,

What ratios of each did you settle on?

Raybo

aconite · March 23, 2014

Someone's been reading Tapla'a articles i see

RootLoops · March 23, 2014

my mother in law does the gravel in the bottom thing. she kills me she'll get a bucket with no holes in the bottom, fill it with a few inches of gravel, dig some dirt from the yard, plant something, and then spend the rest of the year complaining about how it wouldn't grow and that "all those plant companies are rip-offs". i used to tell her she had to have holes and good dirt but after a while i just gave up.

i would also like a good homemade container recipe i'll be checking this thread!

Cole_Robbie · March 23, 2014

I think there are three aspects to a mix - aeration, moisture retention, and organic matter/fertilizer. Perlite is almost always used for aeration because it is cheap. Moisture retention can be vermiculite, peat, or coir. Then the last element is where everyone seems to have their own recipe. Worm castings are probably one of the best ideas, but they are ungodly expensive. I bought some mushroom compost this year that I am going to use - it looks like black dirt, just like worm castings. I think any sort of compost would work; it depends on your budget. I like to mix in a little high-P guano and greensand as slow-working organic fertilizers. I also cheat and use Osmocote, too. (not the high-N, though, read the label) It's a pelleted time-release chemical fert.

My mix this year is going to be 7 parts perlite, 6 parts peat-based pro mix, and 5 parts mushroom compost/organic fertilizers. I also add a little mycogrow from fungi perfecti. I tend to add some sort of fertilizer at every watering, even if it is only a bit of alaskan fish, kelp, molasses, or epsom salt. When the plant is fruiting, I give it some of the two fertilizers I use in the fertilizer injector, calcium nitrate and another that is 4-18-38. Earth Juice sells a high-K organic product called "Meta-K" that would do the same thing for anyone trying to stay organic.

Ed of Somis · March 23, 2014

The University of Calif. and many other organizations have great literature/info regarding this subject of soil mixes. Also, there is info online with the "other" tomato site and the "other" gardening site. Trial-and-error is my best teacher. Cole has some good ideas above....As far as ratios...I think it is really NOT an exact science because of the many variables (ie: crop grown, weather, locale, available sun hours, etc). Many products like perlite and pine bark appear to simply be "aerification type fillers"...their biggest value is really to provide an area that allows the roots to grab water and nutrients within it's structure. This principle is where products like "MiracleGro Moisture Control" goes too far. The polymer ball-like structures retain too much moisture for most container applications, and the plants do not have the water/nutrients available 24/7...if you know what I mean.

PS (added later) We have not scratched the surface as to nutrients for containers. Again, Cole (above) has brought some good ideas to the table. I would recommend learning exactly what a "complete" fertilizer is. Trace elements added are of most importance when container growing.

ScottinAtlanta · March 23, 2014

Tania published a great container mix recipe a few months ago. I can't find it now - but perhaps she can publish it again.

aconite · March 24, 2014

when someone asks about how to prepare a container mix, usually with the idea that there absolutely MUST be some compost or similar small particle component, i always advise to first make about half a liter of whatever they want to use and put it into a completely see through plastic cup, with holes in the bottom. then to let through a couple of liters of water and observe what happens.
this will nicely illustrate what Ed wrote above: "How many bb's does it take to make pudding drain??". The more water you let through (which simulates the waterings during the growing season), the more you will see your dusty particle component sink to the bottom and clog the container. it will also raise the perched water table in the cup, and with it create anaerobic conditions in the bottom. A particularly bad combination is compost and perlite, because perlite floats and moves to the top of the container very fast, but it happens that sometimes people only have access to perlite.
there is much more to this, but this simple experiment usually gets people thinking and tinkering with their mix until they see satisfactory water movement in their test cup.

there is one beautiful article that gives a very good understanding of how water behaves in container media, i always link it in posts like these, take a look it, it isn't long or hard to read:
http://oregonstate.edu/dept/nursery-...roperties.html

there is also a sort of easy solution if you can find this material, dr. Mark Dimmitt wrote an article about using coconut husk chunks (NOT coco peat, that stuff is awful) as a universal container media: http://www.tucsoncactus.org/html/gro...June_2013.html
sadly i can't find coco chunks anywhere near me and i've had no success finding a source online in the EU who can ship for even a relatively decent price (if any of you from the EU know of one please please let me know?), but you guys in the US should be able to get this.

zipcode · March 24, 2014

I see on UK forums they mostly use compost over there in containers and they seem to have jolly good production. It probably depends what exactly is in the compost I guess, but I wouldn't dismiss it as something terrible that should never be used.
I myself have used flower mix, which is pretty much peat (preferably coarser), and I've been happy.

Ed of Somis · March 24, 2014

lively conversation here...and many excellent points to consider. Glad I started this thread! It really is an important subject for the container grower.

Sodak · March 25, 2014

I use homemade "Mel's mix" from the square foot gardening guru.
I found sq ft too jungle like but like the mix.
Basically 1/3 of each of the following:
Perlite
Peat Moss
Compost manure - differing manufacturers of this.

Dump similar amounts of each by volume on a tarp and flip back and forth several times. Then load your pots or raised beds.
I use Texas Tomato food with it and it works well.

Ed of Somis · March 25, 2014

I have tried to mix similar products as above. However, my compressed bales of peat moss are just impossible to separate and take apart.

peppero · March 26, 2014

does anyone have any thought/experience about using nut shells such as peanut, almond, pecan etc

jon

GrowingCoastal · April 27, 2016

Quote:

Originally Posted by Sodak

I use homemade "Mel's mix" from the square foot gardening guru.
I found sq ft too jungle like but like the mix.
Basically 1/3 of each of the following:
Perlite
Peat Moss
Compost manure - differing manufacturers of this.

Dump similar amounts of each by volume on a tarp and flip back and forth several times. Then load your pots or raised beds.
I use Texas Tomato food with it and it works well.

Bless your heart for mentioning the tarp method.

I was so tired of mixing in a tub and kept wishing for a small cement mixer. The tarp is much more convenient and a great way to mix many pots worth of soil in one go. Too heavy for me to flip a lot of soil at once but with the flat side of a rake to spread it out and then flip the edges inward it worked great and my old shoulders don't hurt as much as they would mixing soil the old way.

kevrow73 · April 28, 2016

I sieve the raw ingredients through a steel mesh placed on top of a wheelbarrow. You can then use the back of a spade to brake up larger peaces such as manure or compacted peat moss.
This produces a very light mix that you can shovel over again to mix even further if you need to. It works well for me and can be done with very little effort.

March 22, 2014	#1
Ed of Somis Tomatovillian™ Join Date: Jun 2013 Location: Somis, Ca Posts: 649	Container Mix...mix your own I have been studying what makes a good container mix...and there sure are many recipes! One thing is critical: drainage. Having a container that is muck on the bottom 4 inches smothers the plant and leads to death. Some people think putting gravel, glass, or even broken pottery around the holes helps. It is not true (seems like it should help...huh?). I will not get into the details and science behind why this happens...just know it does. We all have pulled out "mucky" plants that were dying....right? Creating a mix that is "free draining" simply involves eliminating small particles that plug up the mix. Adding larger particles like perlite, pine bark, gravel, etc....does not help a mix with small particles (like garden soil). How many bb's does it take to make pudding drain??? You get it....right? Adding a wick that is in the bottom of the mix and extends out the bottom hole is a great answer. Simply explained...the cohesive tension shared by the wick and the mix "fools" the mix into "thinking" the pot is deeper. Thus, perched water continues to drain. Not the scientific explanation...but you get it. Today I planted many containers for my tomatoes using differing amounts of: pine bark (orchid bark), perlite, compost, amend, peat moss, and palm/cactus potting mix. I wicked most of my pots, as well. Whatever you do...do not use MiracleGro "Moisture Control". It makes the muck factor worse (maybe for hanging baskets I suppose). Happy Spring!

March 23, 2014	#6
Ed of Somis Tomatovillian™ Join Date: Jun 2013 Location: Somis, Ca Posts: 649	More on containers The University of Calif. and many other organizations have great literature/info regarding this subject of soil mixes. Also, there is info online with the "other" tomato site and the "other" gardening site. Trial-and-error is my best teacher. Cole has some good ideas above....As far as ratios...I think it is really NOT an exact science because of the many variables (ie: crop grown, weather, locale, available sun hours, etc). Many products like perlite and pine bark appear to simply be "aerification type fillers"...their biggest value is really to provide an area that allows the roots to grab water and nutrients within it's structure. This principle is where products like "MiracleGro Moisture Control" goes too far. The polymer ball-like structures retain too much moisture for most container applications, and the plants do not have the water/nutrients available 24/7...if you know what I mean. PS (added later) We have not scratched the surface as to nutrients for containers. Again, Cole (above) has brought some good ideas to the table. I would recommend learning exactly what a "complete" fertilizer is. Trace elements added are of most importance when container growing. Last edited by Ed of Somis; March 23, 2014 at 03:54 PM.

March 25, 2014	#11
Sodak Tomatovillian™ Join Date: Mar 2013 Location: 5a SD Posts: 253	I use homemade "Mel's mix" from the square foot gardening guru. I found sq ft too jungle like but like the mix. Basically 1/3 of each of the following: Perlite Peat Moss Compost manure - differing manufacturers of this. Dump similar amounts of each by volume on a tarp and flip back and forth several times. Then load your pots or raised beds. I use Texas Tomato food with it and it works well. __________________ Fight the good fight, finish the course and keep the faith

March 22, 2014	#2
rnewste Tomatovillian™ Join Date: Apr 2007 Location: Campbell, CA Posts: 4,064	Ed, What ratios of each did you settle on? Raybo

March 23, 2014	#3
aconite Tomatovillian™ Join Date: Jan 2014 Location: Croatia Posts: 42	Someone's been reading Tapla'a articles i see

March 23, 2014	#4
RootLoops Tomatovillian™ Join Date: Feb 2014 Location: rienzi, ms Posts: 470	my mother in law does the gravel in the bottom thing. she kills me she'll get a bucket with no holes in the bottom, fill it with a few inches of gravel, dig some dirt from the yard, plant something, and then spend the rest of the year complaining about how it wouldn't grow and that "all those plant companies are rip-offs". i used to tell her she had to have holes and good dirt but after a while i just gave up. i would also like a good homemade container recipe i'll be checking this thread!

March 23, 2014	#5
Cole_Robbie Tomatovillian™ Join Date: Jun 2012 Location: Illinois, zone 6 Posts: 8,407	I think there are three aspects to a mix - aeration, moisture retention, and organic matter/fertilizer. Perlite is almost always used for aeration because it is cheap. Moisture retention can be vermiculite, peat, or coir. Then the last element is where everyone seems to have their own recipe. Worm castings are probably one of the best ideas, but they are ungodly expensive. I bought some mushroom compost this year that I am going to use - it looks like black dirt, just like worm castings. I think any sort of compost would work; it depends on your budget. I like to mix in a little high-P guano and greensand as slow-working organic fertilizers. I also cheat and use Osmocote, too. (not the high-N, though, read the label) It's a pelleted time-release chemical fert. My mix this year is going to be 7 parts perlite, 6 parts peat-based pro mix, and 5 parts mushroom compost/organic fertilizers. I also add a little mycogrow from fungi perfecti. I tend to add some sort of fertilizer at every watering, even if it is only a bit of alaskan fish, kelp, molasses, or epsom salt. When the plant is fruiting, I give it some of the two fertilizers I use in the fertilizer injector, calcium nitrate and another that is 4-18-38. Earth Juice sells a high-K organic product called "Meta-K" that would do the same thing for anyone trying to stay organic.

March 23, 2014	#7
ScottinAtlanta Tomatovillian™ Join Date: Jul 2011 Location: Atlanta, Georgia Posts: 2,593	Tania published a great container mix recipe a few months ago. I can't find it now - but perhaps she can publish it again.

March 24, 2014	#8
aconite Tomatovillian™ Join Date: Jan 2014 Location: Croatia Posts: 42	when someone asks about how to prepare a container mix, usually with the idea that there absolutely MUST be some compost or similar small particle component, i always advise to first make about half a liter of whatever they want to use and put it into a completely see through plastic cup, with holes in the bottom. then to let through a couple of liters of water and observe what happens. this will nicely illustrate what Ed wrote above: "How many bb's does it take to make pudding drain??". The more water you let through (which simulates the waterings during the growing season), the more you will see your dusty particle component sink to the bottom and clog the container. it will also raise the perched water table in the cup, and with it create anaerobic conditions in the bottom. A particularly bad combination is compost and perlite, because perlite floats and moves to the top of the container very fast, but it happens that sometimes people only have access to perlite. there is much more to this, but this simple experiment usually gets people thinking and tinkering with their mix until they see satisfactory water movement in their test cup. there is one beautiful article that gives a very good understanding of how water behaves in container media, i always link it in posts like these, take a look it, it isn't long or hard to read: http://oregonstate.edu/dept/nursery-...roperties.html there is also a sort of easy solution if you can find this material, dr. Mark Dimmitt wrote an article about using coconut husk chunks (NOT coco peat, that stuff is awful) as a universal container media: http://www.tucsoncactus.org/html/gro...June_2013.html sadly i can't find coco chunks anywhere near me and i've had no success finding a source online in the EU who can ship for even a relatively decent price (if any of you from the EU know of one please please let me know?), but you guys in the US should be able to get this.

March 24, 2014	#9
zipcode Tomatovillian™ Join Date: Jun 2010 Location: Romania/Germany , z 4-6 Posts: 1,582	I see on UK forums they mostly use compost over there in containers and they seem to have jolly good production. It probably depends what exactly is in the compost I guess, but I wouldn't dismiss it as something terrible that should never be used. I myself have used flower mix, which is pretty much peat (preferably coarser), and I've been happy.

March 26, 2014	#13
peppero Tomatovillian™ Join Date: Jan 2009 Location: selmer, tn Posts: 2,944	does anyone have any thought/experience about using nut shells such as peanut, almond, pecan etc jon

April 28, 2016	#15
kevrow73 Tomatovillian™ Join Date: Dec 2015 Location: Wales Posts: 66	I sieve the raw ingredients through a steel mesh placed on top of a wheelbarrow. You can then use the back of a spade to brake up larger peaces such as manure or compacted peat moss. This produces a very light mix that you can shovel over again to mix even further if you need to. It works well for me and can be done with very little effort.