That mix sounds fine.. Always test it before growing in any ground or mix.. Add a gallon or so of water and see how fast it takes to drain.. Also take note on the water retention..

A mix that works for me is:

2 parts compost
1 part bark or perlite

You could always just substitute the vermiculite for compost in your mix..
Compost adds nutrients and beneficial microorganisms.. Vermiculite is just inert and doesn't do anything as far as nutrients for that soil.. It's just an expensive way of water retention.. Either way i think the mix would be fine.. But the compost would provide more nutients.. Remember always check drainage and water retention and adjust mix currectly before planting..

Joe

Compost in a container requires a whole lot more care than most people would care to take on.

2 parts vermiculite isn't a substitute for 2 parts compost...water would run straight through vermiculite, especially at 2/3rd of a substrate mix.

Most pine bark fines for container mixes contain a good amount of very fine particles along with the bigger particles. Generally, you want them around 1/2" - 5/8" on the large size...but you'll want some smaller/finer particles mixed with those larger pieces. The more fine particles, the more water retention...the more larger particles, the more aeration.

You can buy a mesh screen to filter your bulk bark fines or make your own with a quick trip to a "big box" store looking for 1/2" metal mesh...or you can eyeball and sort it out if you have the time. You can use the leftover larger bark pieces as a mulch elsewhere or crush it and sift again. Fwiw, I use 1/2" metal chicken wire mesh attached to an old large-ish picture frame I got at a flea market for a few bucks.

5 parts pine bark fines + 1 part spag peat + 1 part perlite or vermiculite (I personally prefer perlite) and 1 tbspn of lime per gallon is a general "all purpose" container mix.

This post was edited by nc-crn on Fri, Apr 5, 13 at 2:01

I used compost in all my container with great result.. What the hassle of using compost? I wod think buying these screens and picking through bark is much more of a hassle.. Why does compost in a container require so much care? I haven't seen that to be the case at all..

Thanks,
Joe

Most people do not want soil in their container mixes...it's a lot easier to regulate and time water + nutrients in a soiless substrate. It's not prone to soil-borne pests or soil-borne disease. It weighs less when wet. Root growth is usually more uniform...etc etc

There's a lot of reasons you don't see many people planting containers with compost/soil. It's possible, but it's generally not as easy to manage.

I have used nothing but the compost I make in containers for years with no problems.

I was going to say, I know I'm not the only on who uses compost.. I believe it's one of the best things you could add.. I could understand houseplants.. But even then, I add compost, and even some garden soil! Works wonders!

Joe

This is what shredded mulch looks like. Mine will be double shredded. Unfortunately I couldn't find a photo of double shredded mulch. Will this be too small?

I am concerned that using compost in place of the vermiculite will cause the soil too retain too much moisture.

I'd like to order shredded pine mulch online, it's not available locally. Does anybody know a site where
I can find it? I've tried searching and to no avail.

It would just be easier and less time-consuming to use single shredded mulch.

http://bradsherfarms.com/files/shredded_pine_bark_mulch.JPG

Yeah, people use compost...a lot of people don't. It's not a "bad idea" if you're using pH balanced and well aged compost...though I wouldn't use 2/3rd of a pot of it in a container. It's very important to properly source your compost/soil if you choose to use anything organic or mineral, though.

There's many ways to make a container substrate. I have 1/5th compost container mixes in some of my long-lasting/perennial mixes for stuff that I don't move around and expect to keep for many years. It's mostly because I'm not trying to push an ideal crop out of a non-ideal situation (a container). I don't monitor these crops as closely, and the compost addition is for supplemental holding/buffering capacity for nutrient exchange.

When it comes to annuals and veggie crops, I want total control in order to push the maximum production out of the container crops. I want total control over my substrate pH/BS/CEC, watering, and nutrient scheduling. It's a lot easier to do this in a soilless substrate. If you're the type that wants to water and walk away, it's not much of an issue. If you're the type that goes around doing CEC/BS/pH tests on your containers every month+ you're not going to get an easy pour-though on a soil-filled medium (or lift the heavy container easily). For me, it's the difference of a few pounds of harvest on a pepper plant (my main annual use of containers). Sure, I could get a good harvest without all that...but I want the best harvest I can get.

It's also way easier for me to schedule water/nutrients based on rainfall, supplemental watering, expected nutrients leeched/used, and heat/sun effects on the container. This may seem like a lot of "work" but if you've been doing it for years it's as easy as looking at a few points of data and knowing where you should be with it...and doing a pour-through if you're unsure or there's been an odd weather event.

I'm not saying compost is impossible or stupid...it's just not ideal for some people for a variety of reasons. For me and some others, it's a control issue...from water/nutrient control to weight/ease-of-movement of the container.

If you're going to use bulk inconsistent-sized shredded pine bark, I suggest you screen it.

The big problem with huge pieces of shredded bark is that a root cannot move through it...it's like putting rocks in your substrate (without the weight). If these chunks get randomly distributed in one part of the container it can lead to uneven distribution of roots, water, nutrient availability, etc... A container is a rather finite space...roots can only do what they can do in the exact space you give them to do their thing.

You can buy some 1/2" chicken wire cheaply...even if you don't want to make/buy a frame for it you can get a piece big enough to fit over a container or roll up the sides for a "handle" or sorts. The 1/2" chunks will fall through (and a few bigger/longer ones), but overall it lets all the ideal fines fall through while stopping the huge chunks that throw off the container substrate mix.

Nc crn- I agree with you for the most part.. But you make it seem like soil less mixes yield much more and is the way to go for productivity.. But, that's not quite the case.. The world record tomato holder, Charles Wilbur uses only compost in his containers and he gets dozens of pounds, if not more off one plant! Not even considering what he does in the ground.. He could feed his whole block, if not town off one plant! He doesn't test for pH or any of that good stuff.. "how to grow world record tomatoes by Charles Wilbur" will give you a better understanding.. Yes you could control your everything about a plant, but I don't thinknthats neccesarily the way to go.. If it was we would have soil mix container gardening holding the world record for container crops.. But sometimes spending your time and money on all the intricate and complex variables doesn't pay off.. Charles Wilbur didnt do anything to special to his soil mix, just added his compost and watered.. Sometimes we need to get out of this scientific "intelligent" thinking and realize the simplicity of everything, it is amazing how much you will learn..

Joe

"Sometimes we need to get out of this scientific "intelligent" thinking and realize the simplicity of everything, it is amazing how much you will learn.."

It's amazing how many controlled experiments I've been involved with using same-cultivar/variety plants and different substrate mixes...it's more amazing to pay attention to what I've learned rather than ignore it.

{{gwi:281255}}

Here's one such experiment I've been a part of with 6 different substrate mixes (3 of them using compost, compost/sand mixtures).

If you're willing to regulate and control your water/nutrient levels the soiless substrate "wins" the health and yield game in this case (raspberries and blackberries, 2009-2010, central NC)...and was less prone to disease. If you're not into that...it may do you little to no good. To some people it's "work"...to some people the simplicity in scheduling and expectations make it easy.

I've also done greenhouse melons and ornamental plantings in container experiments using multiple substrate types. In some cases there's little/no difference except container weight...in some cases there was a notable difference in substrate mixtures. It shouldn't be surprising that the melons hated the container soil/compost mixtures...most ornamentals didn't like it, either. Trees/shrubs (except some evergreens) seemed to like it.

It's almost important to know that what works in one area maybe/probably/more-often-than-not doesn't work in other areas. Growing tomatoes in the Pacific North-West is a different beast than growing tomatoes in the South-East no matter how much container mixes match. There is no "universal care" formula...there are, however, known regional/cultural knowledge and undeniable facts about how plants use water/nutrients based on those regional/cultural factors.

We've long known what almost every plant out there needs, and at what point in their life cycle they need it, to have near-perfect production. For instance, the types of N applied and how using NO3 vs NH4 at different times of a corn's life cycle can dramatically effect your final yield and plant health... I don't expect most home gardeners to "get into it" on a level of having multiple N sources, but for those of us that do "get into it" on that level, it's as useful of a tool to use to grow a plant as any. Though it sounds "all sciencey" or something...it's little more than knowing a plant is this old, has this many leaves, is showing this part of it's production cycle...and when/what to apply during that part of it's cycle. It's a learned skill, but it's not anything that takes practice to master...just the knowledge of the method.

Sometimes we need to get into this scientific "intelligent" thinking and realize the simplicity of science, it is amazing how much you will learn..

A lot of research...and ultimately, findings...involves a massive amount of very simple "steps." It's not all test tubes, monitoring equipment, and expense. A lot of growing/nutrient research is massive plantings in a single culture/environment with subtle differences trying to hone in on what subtle differences make the most impact.

Those of us that want to use the knowledge gained from these experiments/results are of no greater or lesser standing than those people that are happy with what they get from their crops that just want to plant, water, and harvest being the end-all of their plant care.

This post was edited by nc-crn on Fri, Apr 5, 13 at 18:52

Just to clarify, the link with the photo of the mulch was single shredded. I will be using double shredded mulch.

I would have posted a link w/a photo of double shredded mulch, but all I could find were photos of single shredded mulch.

My concern is if I use double shredded mulch, will the soil retain too much moisture?

I'm confused because I've heard some say if the texture of the pine bark fines/mulch is too coarse it'll dry out too fast and won't be suitable for use in container gardening due to the size of the mulch being too big.

Others think if it's too finely shredded it'll retain too much moisture. I'm just trying to find a happy medium where it retains enough moisture that it doesn't dry out too fast, but where it's not retaining too much moisture.

Will using the double-shredded mulch accomplish this?

Also I'd like to be able to reuse it as well (for the following year). If I use the double-shredded mulch will this be feasible? Is it possible to store soil less mixes over the winter and reuse them?

Last but not least I'd like to add a little compost but the soil less mix I use calls for 2 cups of Oscmocote per batch. Should I omit it entirely or just reduce it?

If I'm using compost, how much per 30 gallon batch of soil? (that's how much one batch of the soil recipe I make uses).

I know I can't use gallons of compost per batch, it'll retain too much moisture (learned this the hard way).

The best thing I could tell you, is fill up a container and test your mix before going gung ho and planting all your plants.. Test is, test it, test! There is many variables to tell you if it will or willnot retain moisture,etc.. I wouldn't not use synthetic fertilizer... You could use a cup or two of compos per container 10-20% I say would work fine.. Th majority if my containers are full of compost, perhaps it's the quality, not sure why people have sonmany problems with it.. Now if you want to reuse it, that'll be tricky.. That's half the reason why I wouldn't us chemical fertilizer, the salts and harsh chemicals will accumulate in the soil, and you will have to "flush" your contains thoroughly with water after each season.. Now if you use organics, it is likely
that the bark and other amendments will decompose and you will have half the volume of potting mix you did when you started, this would even happen with synthetic fertilizer.. It is unlikely that you can reuse the mix without adding more of the mix each season.. I wouldn't even both reusing it if you are using synthetic chemical fertilizer, like a said it will accumulate in the potting mix, not a good thing.. The only way i could see you reusing a mix is if it completely inert.. I would use compost tea and other organic fertilizer,etc for your container plants... I had great success using these methods.. Like I said the best thing you could do is test the mix before you plant in it to make sure you are satisfied.. If not you could always amend and change it.. But if your plants are in it, your kind of stuck.. Test test and test!

Good luck,
Joe

Good luck,
Joe