Hey Containergirl,

If my math is correct a 20 quart bag is less than 1 cubic foot of mix. Potting mixes are sold in 2.2 cubic foot bags for around $7-$12 at most anywhere that sells garden stuff.

If the mix you are now getting is just peat, vermiculite and perlite with a little lime tossed in, that makes it pretty much the same as any other bag of peat based potting mix. Some store mixes may also contain other things like bark pieces.

Anyway, if you were pleased with the mix you used last year you can save a ton of money by buying from local stores in the 2.2 cubic foot size.

I, personally like Miracle Grow and Perfect Mix brands because they are the most common in my area and the least expensive that does what I want it to. Others have different brands they prefer.

Yes, you will save money mixing your own *if* you can find each ingredient in the bulk sizes rather than the tiny little bags. Just thought I would point out that the 'specialty' mix you used and liked last year is indeed hideously overpriced for what you are getting.

I bought a bag of Miracle Grow last year, and I didn't like how it felt. Gritty. Not nearly as nice as the Gardeners Supply stuff. But I guess it doesnt' matter what it feels like in my hands, it only matters how well stuff grows in it! I had no problems with that one Miracle Grow container, but I just have to get over the "yuck" factor when planting it.

Since it is essentially the same as an earthbox you can get a lot of helpful information by going to earthbox.com and browsing around. In short, they recommend any good brand of potting mix. You don't want anything labeled potting soil. Jmalt31 has posted links in this forum (search the forum for his name and you will find them) instructions for homemade self watering containers which contain a section on what mix to use and on how to mix your own.

One key thing to keep you on the right path is to only buy potting media measure by volume not by wieght. I run into this all the time at the garden center because people are shopping price not quality. I try to help them understand that a fluffier material that has better air and nutrient exchange will give you a muc better plant. Poor plants because of the wrong media is just a waste in my opinion and has many folks not wanting to container garden when it was all their fault just the stingy part of themselves got them in trouble. I love to mix my own media because I am using a given mix for a give plant or culture condition so I cater my media to that to perform its best be it short or long term its worth it to me to get what I want that no prepackaged material can offer. That being said I think sticking with a name brand be it miracle gro, schultz or sunshine any of these should serve your purpose and yes you are paying a premium price for what you got last year and you can do better price wise and your performance need not be hurt in the trade. 2 cu. ft or bigger will usually get you the best price. Remember that 1 cu. ft. equals 25.4 quarts. The companies are IMO always trying to take advantage of the public for there lack of knowledge and I for one think this is a terrible business practice but I can only help those I can reach.
We are all learning to work with what we know and what is available to accomplish our plant goals.
Good Luck and Happy Growing David

I mix up enough to fill 2 33 gallon trash cans at one time on my drive way. Shovel works just fine for blending the different ingredients together.

That way I always some soil around and it is protected from blowing weed and tree seed.

randy

I got my container soil costs down to around $2.75/cubic foot by mixing my own. I'll catch a Home Depot or Menards sale on peat moss and buy as many bags that will fit into my van. If it's a good enough sale I'll make two trips. There's a garden shop by Oprah's studio (1000 W. Randolph) that sells 4 cubic foot bags of perlite for $20. And there's a place (Farmers Market) on 40 something north Elston that has pallets of that pine bark stuff (at least they did last year).

I use two 20 gallon utility tubs for mixing, measuring and filling the ingredients in one tub and then dumping the soil from tub to tub to mix it all together. It can be a lot of work and takes time but I do save a lot of money and there's a certain satisfaction later in the season knowing that it was my soil that produced that not some big corporation's mix.

Mea - you figured out I'm in Chicago! Thanks for all the details. Excellent! Now I have to decide if I want to go through the hassle. It's so easy to point and click and have it delivered, LOL. Yes, I'm pretty lazy. I guess I could plant up the 20 gallon tubs when I'm done with the mixing to have a place to store them.

Oh Mea2214, I remember you now after checking out your page! Sorry to have forgotten. Love your pics of your rooftop container garden!

Yeah, mixing your own does take a lot of driving around to different places in order to find ingredients. Here in Chicago city proper I found that most nurseries stock the standard bagged soil and very few have the components. Where I used to get perlite last year stopped carrying it in the big bags and it took a lot of calling around to find the only place around here that has the big bags (1000 W. Randolph). I'm really hoping that that guy at the Farmer's Market orders pine bark this year or I'm going to be have a lot of problems this year. Next month I'll drive over there and have a chat with him. :-)

My biggest problem with mixing my own was figuring out a formula that works with my garden. I used a modified version of the formula tapla had posted here. Last year was a huge experiment for me and it seemed to work out well. I don't know anything about what kind of soil is required for self watering containers such that the water wicks up properly. I don't have any self watering containers. This year I'm going with a drip irrigation system instead.

As for the 20 gallon plastic utility tubs, the ones you can get on sale sometimes even at grocery stores, aside from mixing soil they also make for a nice temporary potting station so you don't make a mess when potting smaller containers. When done and washed out you can put stuff in them and use them as storage containers.

BTW: Make sure you update your website describing your garden this year too!

Perlite, wood chips and peat. Is that all, sounds a little void of nutrients. Did I miss some ingrediants?

Fertilizer, LOL! I'm still learning all about growing media, so I can't say much else except that this mix (sphagnum peat, perlite, vermiculite, and limestone) worked wonders for me last year. I have been considering a worm bin for my own compost, but I don't want to store that in the pantry. Eeuw.

Anybody want to endorse or bash Sta-Green from Lowe's as the potting soil of choice for earthbox container systems?

I am going to celebrate President's Day by starting seedlings of tomatoes in two (2) earthboxes. All I need are the seedlings, the soil, and the recommended amendments to guarantee my summer of lucious vine-ripened beauties.

Thanks for you input.

Anybody want to endorse or bash Sta-Green from Lowe's as the potting soil of choice for earthbox container systems?

I haven't used it, but understand it to be a peat based mix. I wouldn't consider it, or any other mix, the 'potting soil of choice' for earthboxes as virtually any potting mix (as opposed to the stuff with actual soil in it) works well.

The earthbox.com site has it's own forum and you can get a good idea there of what people are using and how they like it.

My personal philosophy when it comes to self watering setups like earthboxes is to buy whatever is the cheapest (on sale) that I know is suitable. About my only requirement is that it not contain any actual soil.

In an earthbox the potting mix itself really doesn't do much other than wick water and provide support. The design of the earthbox ensures even moisture and good aeration with pretty much anything other than the soil based stuff which is too heavy for containers period. The fertilizer strip takes care of the fertility.

Just add plants and water ;-)

Thank you for the timely reply.

My neighborhood Lowe's is selling the 3 cubic foot bag @ $11. As I want to get started tomorrow, I will not wait for a sale.

I take it you believe the rock phosphate and hydrated lime to be superfluous amendments.

My concern about adequate aeration is based upon the relative low air volume between the top of the water reservoir and the bottom of the potting soil layer. The small water drainage hole does not provide much air passage. The concept of adding ventillation (more than aeration) by using pipes with holes open to the sides of the container is fascinating, but maybe it is overkill.

Enjoy Presidents' Day! Happy Gardening for 2007, everybody.

"In an earthbox the potting mix itself really doesn't do much other than wick water and provide support."

Now this makes sense and helps me understand. You'd think I would have figured that out by now, but I learn more every day here at Garden Web. I have a long way to go to live up to my user name!

How do you think compost would do in an earthbox-like container? Does that get too heavy?

Thanks for the well wishes, Pistachioman. Good luck with your tomatoes!

I take it you believe the rock phosphate and hydrated lime to be superfluous amendments.

Rock Phosphate yes, Lime no.

The addition of lime is something I have doubts about if there is ample calcium in the fertilizer used (not a given) and I do not at all buy the idea that it is needed to raise pH of container mixes for tomatos. I don't know where the earthbox people got that idea from.

I asked this question to one of the chemistry oriented earthbox employees via email as well as on the earthbox.com website. The individual I was corresponding with eventually agreed that their (earthbox) stated reasons for adding lime might not be entirely accurate, but he would have to look into it more. Subsequently he left the company and nothing further has been said on the issue. My concern about adequate aeration is based upon the relative low air volume between the top of the water reservoir and the bottom of the potting soil layer.

The size/volume of the air layer isn't very important. The ability of the growing media to allow air into itself matters though which is why I have no use for heavy, soil based potting mediums. As far as the peat based mixes go they all seem about the same to me. If you want, try a really porous mix like 'Al's mix' in an earthbox and compare it to an earthbox with 'regular' mix and see what happens.

Some folks have modified their earthboxes by drilling a hole opposite the overflow hole. This will allow greater air exchange within the air layer of the earthbox, but whether this adds up to any difference in plant performance I really don't know.

How do you think compost would do in an earthbox-like container? Does that get too heavy?

I haven't tried pure compost in an earthbox so really can't say. In general though I am not a fan of compost (in high amounts) in containers.

Primary reason is it breaks down so quickly that by the end of a short season I am left with a container originally filled to within 1" of the rim that is now 4+" below the rim. I don't care for that.

I also think filling a container with compost is a waste of perfectly good compost that would perform mini miracles in the soil based gardens.

Having said that if you have access to sufficient quantities of compost to meet all your needs go ahead and use it. Only you can determine what you do and do not like based upon your own experiences and results. I don't really care for compost in containers, but I know of those who use nothing but compost in containers and appear to be perfectly satisfied with the results.

Maybe try one container with and one without and compare the two. Fun little experiment.

Hydrated lime? In containers?

Containergirl, I don't know if this will help you at all, but for my soil this year I'm going to try an experiment. I'm planning on adding to my old soil from last year perilite, compost, peat moss, some bark and lime. I'm not sure of my measurements yet. I'll probably just wing it once I'm putting it all together. I made my own compost this year and as I will be using last year's soil, I'll be saving some money. Just a thought.

Containergirl, I agree with mommie rose. There is a lot of life left in last year's soil, so amend it with a little more of the stuff you like, then fertilize, fertilize, fertilize. Unless you threw it out.

Since you don't already have a lidded tub for storing your garden tools in winter, buy one to do the amending in, then store your tools in it next winter. Or plant it.

I have no experience with self watering containers but after seeing jmalt's instructions for building one decided to try them this year. I have learned a lot about them by browsing around the earthbox.com site visiting the forums and reading the faq's. The point of my post is this faq:

Is the EarthBox reusable? How do I replant my plants?
Absolutely. Simply remove your old plants, the old fertilizer strip and some of the surrounding potting mix. Decide what you are going to plant in your EarthBox and refer to the plant placement guide to know where the fertilizer and plants need to be placed. Top the EarthBox off with some fresh potting mix; create a mound with the fresh potting mix where the fertilizer strip will be placed. Pour 2 cups of fertilizer in a 2-inch-wide strip on top of the newly created mound, recover the box and replant. You can use the same potting mix for 5 growing seasons and the EarthBox for many years.

If you keep the previous year's soil mix, and amend it with 50% new mix, after 2 seasons you end up diluting the original mix to 25%, and after 3 seasons to 12.5%, etc...this is an effective way to maintain a reasonable budget without sacrificing too much in terms of soil-mix quality.

Keep in mind that most commercial mixes have high %'s of peat, which tends to breakdown into a useless muck after about 2 growing seasons, so it must be amended adequately with large particle aerating media such as perlite, bark chips, fine gravel, turface, pumice, whatever you can get your hands on will suffice. The additon of some organic matter (compost or topsoil) in small amounts will not be detrimental, but do not rely on it for the plant's nutrition.

The mix should drain as quickly as you water, that's how you know it drains well. It should not hold together if you grab a handful, instead it should crumble apart.