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I want to make my own potting soil

Posted by piper101 Z9 (My Page) on
Fri, Mar 21, 08 at 5:10

This is what I have in bulk; peat moss, pumice, organic compost starter/soil amendment (I forget the exact name right now) by Gardner & Bloome, Dr. Earth Oranic 7 complete fertilizer, sm. amount of perlite, chicken manure, alfalfa and sand. I was hoping to use the compost starter and amend that but when I opened it for the first time it just felt too woody to me. I know it has these mycorrhizae and other good stuff but it didn't seem like it was the right thing to start adding into. Maybe I'm so used to a clay type of dirt that I'm off track here but what else do I need?,,,No commercial potting mixes or super soil for me please,,unless they are gardner & bloome,,,maybe I just bought the wrong mix? I need it in bulk so when I saw the 3 cu ft block for this great price from the county farm supply I just grabbed them.

What do I need to get now? Thx.


Follow-Up Postings:

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RE: I want to make my own potting soil

What are you planning on growing?


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RE: I want to make my own potting soil

"Compost Starter" is a high Nitrogen product that would not make a good addition to potting soil, but you can make your own potting soil. The best material to use is compost, and that is what I have used for many years, just compost, no soil, no peat moss, no anything but the compost. A search of the internet will yield some 240,000 articles on making your own potting soil and many that I have looked at are soil based and soil is just to heavy to use in pots.


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RE: I want to make my own potting soil

ditch the peat moss, use compost in place of it - it's better anyways for your plants


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RE: I want to make my own potting soil

Compost is NOT the way to go for container plantings. See my response to your other post on the Soils forum or check out the Container forum for more appropriate advice. Container culture is a very distinct situation from inground growing conditions and requires a very different approach. Or google "potting soil recipes" for help. Contrary to what has been stated, most potting soils are "soil-less" mixes but it is most often recommended that compost play a very small role in these recipes.

And yes, there ARE excellent Gardner & Bloome potting soils. Look for their Blue Ribbon Blend. The soil building compost product you bought (the only one of their products available in a 3cf bale) is intended for amending soil in planting beds or mulching, however the "woodiness" is not a concern - you do want the texture and particle size that some woodiness provides but you also want lightness and increased drainage, so this is not the best choice. FWIW, ALL G&B products are innoculated with micorrhizae and other soil microbes so facilitate the use of organic ferts, which most other commercial mixes do not.


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RE: I want to make my own potting soil

soo... the 3 chili plants I have growing in straight compost, that have wintered over and produced hundreds of cayenne, habanero, and seranno peppers are not doing well?? I also make my own soil/soiless mix blends, but these three are an experiment that seems to prove that good, varied compost IS all you need. Granted, the mix has reduced in size, but I just add more on top of it, and off to the races we go. I bet you that I can take these peppers 4 years,with no other amendments than my compost, and they may not outperform my container mix plants, but will be just as healthy. Wanna bet???

BTW, all finished compost has an abundance of microlife in abundance, including micorrhizae, and my 8 gallon and 12 gallon containers that I am talking about, retain water yet DRAIN FREELY. While all compost may not be the way to go for container planting, there are millions of happy container plants that are growing away in compost everywhere. I probably will not plant in straight compost this year with the 36 or so 5 - 12 gallon containers that I will have planted, I wouldn't have enough compost for that and the garden but there will be atleast 10-20% compost in each container. You go and have yourself a wonderful day now - you hear? Good luck TiMo


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RE: I want to make my own potting soil

I love and will pay extra for products with micorrhizaes (sp?) so that is what turned me onto Gardner and Bloome products for bagged products. I've used EB Stone and Dr. Earth that I really like as well. I've switched to Dr.E for cost savings but I've gone thru potting soil fast over my short time delving into gardening so I didn't know any better. I'm looking to transplant all my hanging and potted plants in new soil to stretch out the time I get out of my perennials since I am such a flower and color type of gal. Now knowing that soil and nutrition can greatly get me to this goal, I've either got to make my own mix to save money (ideally) or buy the best I can get. Planting into my ground soil is not problem as I can amend it to what it needs but I don't have enough actual dirt to use that in my potting mix, thus the problem.

I just took 3 classes at my local specialized nursery and being the prolific note taker and hand raiser that I am, the guy said that compost lowers the oxygen which equals rot so especially for container pots that you need airspace and drainage and that commercial soils use to much wood product( don't know if fast or slow decomp wood product). So I had 3 huge cubes of compost builder (G&Bloome), I put 2 out thickly over a raised bed of perennials I have and will save the other bag for part of my "recipe".

In looking back thru my notes just now, what do you think of a recipe of 85% peat moss and 15% perlite that will give about 20% airation?,,We have the heat to contend with. I also have written down 50% pumice for more airation since it's more poreous than perlite,,,I just have it written so fast that I may have missed something here. It is true that peat moss holds moisture for 5 yrs?

Now that I've been enlightened or just the tip of the iceburg to all this, I'm wanting to replace the soils in my potted and hanging plants since in So.Calif I'm having to water almost daily right now and it will only continue more so when summer gets into full swing.

I'm wanting to creat a soil for transplanting them so that I get a better moisture holder as well as maintaning drainage. I guess I know just enough to be dangerous at this stage but I'm learning!


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RE: I want to make my own potting soil

gardengal, According to Dr. Elaine Ingham President of Soil Foodweb Inc. properly mixed aerobic compost can be used as potting soil as long as it has protoza, fungi, and bacteria.


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RE: I want to make my own potting soil

"the guy said that compost lowers the oxygen which equals rot so especially for container pots that you need airspace and drainage and that commercial soils use to much wood product"
There may be a time in the composting process that that would happen and if one were to keep that compost in that container too wet that could happen, but then rot can happen even in the expensive potting soils I bet this guy sells. That statement is nonesense.
The mixture of 85 percent peat moss and 15 percent perlite is a common on in commercially available potting soils.


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RE: I want to make my own potting soil

Why can't you use compost in indoor soils? I always thought you could, although I do know that most mixes are "soiless" (but why?)


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RE: I want to make my own potting soil

I add perlite to my compost and use it for potting mix, it works great. The perlite helps keep it light. I am a passive composter, I have lots of room and so i move the pile every few years but it doesn't get turned much, just piles up and "composts".


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RE: I want to make my own potting soil

Oh please. Nobody have that amount of compost and it can get expensive in a hurry. Common sense folks...


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Go to Cointainer forum

Please go to Container forum. This topic has been covered many times. Better information too by someone who actually knows one or two things more than someone like Horrayfornuts and Kim-know-it-all.


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RE: I want to make my own potting soil

Compost works for indoors. I'm not sure what you're all talkin about.


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RE: I want to make my own potting soil

The problem with compost in containers is that it doesn't do any good.

What does compost actually do in soil that makes us want it? It immediately loosens the soil, it feeds soil organisms, it provides some nutrients etc, it can compete with disease organisms etc.

How would it do this in a container? There won't be any fungi in compost in a container, they get too hot for fungi to survive and the bacterial populations will fluctuate with the temp and moisture levels in containers.

It will also break down in a season to virtually nothing resulting in lost volume in the container.

I just don't see the point of compost in a container. At best it does nothing good and at worst it reduces oxygen as it breaks into smaller and smaller particles eliminating the air spaces in the planting mix and holding on to water to the exclusion of oxygen.

I am not saying there aren't those using it who are happy with the results they get, just that I don't see any value to it. The compost would serve a much more valuable purpose in the ground where it fuels a soil system.

A container is not a small piece of a yard, it's an unnatural plant enclosure subject to extreme temperature and moisture fluctuations. It isn't a system where water, oxygen and nutrients flow through in a natural manner. The water, nutrients and oxygen all have to be added throughout the season by the grower. Put a plant in a container and let nature take care of it and we have a dead plant ;-)

Compost=great in the soil and at best, pointless and wasteful in a container.


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RE: I want to make my own potting soil

How does finished compost get too hot?

How does it get broken down in a container at the same rate that it would outside? It doesn't because there's barely any biological activity in containers. So how's it gonna break down in a season any more than peat moss would?

Here's why compost is better - 1)it's easy and cheap to make, 2)it helps the environment by avoiding destruction of peatlands, which miners open up to severe drainage which unlocks enormous amounts of CO2 to go into the atmosphere (draining peatlands = decomposition of carbon sinks)

How anyone could say compost is wasteful in a container is beyond me, when compost could be made from waste, and when it's better than peat moss in terms of bulk density and soil structure:

"Compost has largely replaced peat moss for improving garden soils. Unlike peat moss, compost has only a slightly acid pH, between 6.2 and 7.2, is rich in essential nutrients for good plant growth and it releases its nutrients slowly. Because its nutrient release rate is highly dependent on soil temperatures, it does not release its nutrients except when the soil is warm and the plants are growing. Unless it is used in excess, it does not contribute to our water pollution problems.

Because its rich brown color is due to its high lignin concentration, it does not shrink like peat moss, thus its effect in reducing the bulk density is long lasting. Research has demonstrated that a single application of 100 tons of compost per acre will provide beneficial effects on soils for at least eight years. Peat moss, due to its low lignin concentration but high cellulose level, will only alter the bulk density of soils for approximately one year. Peat moss is void of plant nutrients and your must balance its use with the addition of limestone to counteract its acidity."

http://www.growit.com/Features/midatl504.htm

Anybody that cares about global warming shouldn't buy peat products, it is akin to aiding in unlocking thousands of years of carbon storage. That is one thing the peat industry has absolutely no way to spin, and something it can never deny.

That's why I prefer compost over buying an indoor soil mix with peatmoss.


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RE: I want to make my own potting soil

How does finished compost get too hot?

It doesn't.

How does it get broken down in a container at the same rate that it would outside? It doesn't because there's barely any biological activity in containers. So how's it gonna break down in a season any more than peat moss would?

Compost breaks down faster because it is easily digestible by microorganisms and peat is not. This makes compost great for soils, not so great for containers. Do you really want to start with a potting mix filled to the container brim and end with a mix 6" below the brim?

Here's why compost is better - 1)it's easy and cheap to make,

I know only a few people who can make enough compost to meet their gardening needs and they live on acres of land. This is a fairly rare thing in the modern world of cities and suburban subdivisions.

2)it helps the environment by avoiding destruction of peatlands, which miners open up to severe drainage which unlocks enormous amounts of CO2 to go into the atmosphere (draining peatlands = decomposition of carbon sinks)

Yes, but as was pointed out in another thread leaving the peatland produces methane gas which is much worse than CO2 as a greenhouse gas. You aren't taking a balanced look at this and I am not arguing for the use of peat moss anyway, just pointing out the pointlessness of compost in a container compared to it's value in feeding soil. You don't need peat moss or compost for indoor potted plants. Heck, all my indoor plants are grown in water and hydroton balls. No soil or soilless mixes. Google 'hydroculture' and you will see how all my indoor plants are grown in a permanent growing media.

How anyone could say compost is wasteful in a container is beyond me, when compost could be made from waste, and when it's better than peat moss in terms of bulk density and soil structure

On what do you base your statement that compost in a container has a better soil structure than peat moss? On what do you base the statement that it is better than vermiculite, perlite or any other common potting mix ingredient in terms of retaining structure? Compost is food for microbes, it breaks down quickly as a result. Of the many fine qualities of compost, retaining structure is not one of them. If it did retain it's structure most of it's value as a (ground) soil amendment would be lost.

It almost pains me to be debating this as I use mostly organic principles for in ground gardening, but when it comes to house plants and outdoor container plants I do understand the the mere act of containing the growing media means I don't have a working soil system. This means I don't bother with the negatives heavy, tiny particled organic matter would introduce to an incredibly unnatural means of growing - containers.

I really don't get why organic gardeners don't grasp this concept. Organics are for the soil. They work great there.

Containers aren't the earth, nor are they tiny equivalents. If you really want to be 100% organic, don't use containers at all. If you do want to use containers, stop trying to pretend they are the earth or work anything like it. Containers work like the earth just like a fish aquarium works like a lake. We can grow the same things in both, but the methods have to be different because one has a natural ecosystem working for it and the other does not.


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RE: I want to make my own potting soil

"Yes, but as was pointed out in another thread leaving the peatland produces methane gas which is much worse than CO2 as a greenhouse gas."

That's just not true, at all. Peatlands do not harm the environment, tampering with them does.


Anyways, if compost isn't great for indoor containers, get coco coir. Don't rape the ecosystem by supporting peatland harvesting, which is unsustainable in every aspect.

To me it's more worth it to use compost for my containers and just repot when needed. Buying coco is ridiculous, buying peat is ridiculous, when compost is free and works just as fine. I'm not so physically incapacitated that I can't find the time to repot the plants I use so I'd rather do what's best for the environment.

Coco lasts just as long if not longer than peat, if you can't afford it at the expense of the environment, that's on your shoulders I guess.


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RE: I want to make my own potting soil

There are some great products you can add to your soil that are all organic and easy to get ahold of. One thing I'm fond of is humus... I've experimented with some different kinds and have found that Alaska Humisoil works really well in all my soil mixtures. Try some of that Root web or a similar product, as it has also helped me out. There are just so many things to use, experimenting is really a good way to go.


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RE: I want to make my own potting soil

  • Posted by byron 4a/5b NH (My Page) on
    Fri, Mar 28, 08 at 19:01

A couple comments

1. Coco coir kills dogs
2. Harvesting peat, makes moose move south and endangers humans. They are now in my area.
3. I make about 1 cu yds of compost per year, more than I need for starts. Plant waste and leaves. Kitchen scraps get composted in the soil


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RE: I want to make my own potting soil

So do you use compost indoors, byron?


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RE: I want to make my own potting soil

I can't believe some of you are so against using compost for house plants. And why would you think you can't make enough to supply your needs? Another word I use for my compost is rich dirt and it is better than that bagged stuff that you get at Walmart. Perlite is all I add to it and my houseplants are all huge and healthy. They only problem I have ever had is with a few weed seeds that pop up when I am starting seeds. But this soil looks better than the bagged stuff and it's free. I don't think I have ever bought peat moss and I get great results from my plants, indoors and outside.


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RE: I want to make my own potting soil

I knew it was possible and my plants weren't crazy. I still don't know just *what* is with this craze of using peat moss for soil, or this craze of thinking that, somehow, compost doesn't work to grow great plants in, or that one HAS to use synthetics and will be OVVVVERRRUNNNNN!!! by swarms and swarms of evil insects!

Thanks spogarden for validating my sanity!


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RE: I want to make my own potting soil

Hoorayfornuts and spogarden -

you are completely missing the point but it's like trying to argue with Al Queda guys. They just refuse to listen.

Peat moss is great when used for the right reason. Like Container plants. Like only 10% by volume. Reason? Much more stable than compost. Compost is much better for the ground. I do it all the time. ya'll just trying to twist truth around to make yourself look good. Pathetic.


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RE: I want to make my own potting soil

Byron, I think you're thinking about cocoa bean husks and their toxicity to dogs, not coco coir (which is a coconut product). The cocoa mulch can be a problem.

I second what Justa says. ;-) Though I barely use any peat moss at all in my container mix.


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RE: I want to make my own potting soil

lou i actually was thinking you were using it 100%. sorry for assuming that.


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RE: I want to make my own potting soil

It's sad to see gardeners getting pissy with each other.


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RE: I want to make my own potting soil

Posted by JackNone 10 (My Page) on Sat, Jan 26, 13 at 21:23
"It's sad to see gardeners getting pissy with each other. "

ONLY what I DO is REAL. ONLY what the EXPERTS say is REAL. We can no longer learn from each other. Too many self-esteem children now own houses and computers and read garden books without understanding the essense of what is being said.

Q. Why can't compost be used indoors?
A. Because.


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RE: I want to make my own potting soil

I successfully raised thousands of daylily seedlings with this formula: 1/3 peat moss, 1/3 vermiculite, and 1/3 perlite. I used dilute liquid fertilizer after they had developed their second set of leaves. I bought one of those big blue tubs at Lowe's and mixed the potting soil in that with a shovel. You do have to wet it down thoroughly before planting your seeds.

Nancy


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RE: I want to make my own potting soil

Here's one from Cornell, they have others as one size does not fit all. Don't anybody get too carried away about defending a particular recipe unless it's for a specific crop at a specific stage of growth in certain containers, etc. these are all variables that impact what works best. I.E. In the greenhouse industry they use different pots and mixes depending on the crop grown and the variety of both mixes and pots is wide.

Just something to chew on. I like my mix for what I've been doing for years here, might be crap for you with what you're doing though:)

Here is a link that might be useful: Cornell mix


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RE: I want to make my own potting soil

Q. Why can't compost be used indoors?
A. Because.

There IS actually a very good and well documented reason why compost is not recommended as a major additive to container potting soil, either for indoor plants or outdoor plants. And that is how it affects good drainage, a quality that is pretty much paramount for any sort of container growing.

Compost continues to breakdown even as a component of potting soil. The longer it goes, the more frequently wetted and the warmer the container is kept, the faster the material breaks down. And when that happens, the individual particles become tinier and more uniform in size, the pore spaces (the empty cavities between particles) shrink and the whole mix compresses. Compression and lack of pore space has a big negative impact on drainage and soggy soil and rotten roots tend to be a result.

That's why most high quality purchased potting soils contain minimal - if any - concentrations of compost. It just doesn't hold up. If you are growing in containers short term, like very seasonal crops, compost can work as an additive (not the base) to potting soil. But for long term success - growing anything longer than 6 months - you want a durable, barky, textural potting medium that is not going to collapse and impact good drainage.

The Container Gardening forum has a detailed discussion on this very subject that is the longest running (march '05) thread on GW. More than 2500 posts have entered into the discussion and the knowledge base is pretty high - in fact, the original author is considered an expert on container soils and container gardening in general

Here is a link that might be useful: Container Soils - Water Movement and Retention


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RE: I want to make my own potting soil

Well said.


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RE: I want to make my own potting soil

Well said.


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RE: I want to make my own potting soil

Maybe my tired eyes missed in that link Gardengal, was any mention made of the importance of adjusting the mix to suit the crop and container, they are important variables.

Darned well thought out link otherwise.


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RE: I want to make my own potting soil

I'm glad 6 months was the number put to it before the texture of the compost becomes noticeably more compact, becuz here our winters only last 6 months and the compost component retains water better than vermiculite and charcoal.


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