honestly? My suggestion is go grab a big bag of any brand name potting soil and use that. Then spend the next year slowly and comfortably learning about why various ingredients are used in various soil mixes, what they contribute and what can be substituted.

There is absolutely no benefit in using a custom soil mix if you don't understand why the ingredients are what they are and what can be used to substitute. When you are at that stage in your knowledge it is a lot easier to go buy an off the shelf mix that will work just fine for you.

Commercial potting mixes sold for $5-10 for a 2 cubic foot bag work spectacularly well for everything other than acid loving plants. They can be improved upon, but my suggestion is start year one using a commercial potting mix while learning. Spend year 2 adding things to the commercial mix to improve it and observe results. Year 3 is for making your own if you are so inclined.

I'll agree with username on this one--there's no sense beating your head against the wall if you can't find exactly what you want, just move to the next best thing. A good commercial mix will probably work fine, they are just more expensive, and because they are usually peat based will also break down more quickly (adding to the expense).

Pine bark fines--usually sold as pine bark mulch or soil conditioner--will probably be easier to find in the spring. That's the way it is in Texas, even though fall is a better time for gardening. There may also be places you haven't checked such as feed stores and independent nurseries.

I've noticed that the good commercial mixes are usually sold by volume rather than by weight. If the bag says 40 lbs. and it's dirt cheap, then it's probably dirt.

Jason

Hi, Amy. Folks have been growing in containers with what's commercially available for a fair number of decades now, so it's obviously not too difficult to get things to grow in commercial mixes. The more you know about a soil's physical and chemical properties the easier your job is. It's also easier to recognize the shortcomings of particular soils and adjust accordingly to compensate.

I have several friends in the nursery business. About 12 years ago, when I first became interested in growing plants on for bonsai, I realized that bagged commercial mixes were entirely inadequate for plantings that were to last more than a year between repots. They simply were not capable of retaining structure long enough to guarantee good aeration and drainage for a full season. I had noticed that my floral container displays would always begin to suffer terribly toward summer's end when using a commercial mix as well. At the end of the season, I would shake out the root-balls & notice the roots wrapped round & round the outside of the root-ball at the container walls. Because I'm always vigilant about watering, I decided that air was what the roots were looking for. I tried amending with perlite the next year & the plants actually did worse. Perlite is only marginally effective at increasing drainage/aeration in a soil whose particulates are already too fine. I realized I had to find a way to get my soils to hold air for extended periods.

I had already studied bonsai soils with a considerable amount of progress in learning why they are so effective. The year after the perlite experiment, I decided to grow my floral displays in the same soil I used for growing on bonsai (essentially a nursery mix). I never looked back.

The mix I grow in is not a mix that is unique to me. It is a close copy of the nursery mix that almost all nurseries use. Pine bark, small amounts of peat, perlite, and some other minor ingredients that a grower might favor, or that particular plants might like are a staple in the nursery trade. If you think about the plants that you buy in a peat based mix - aren't they all or nearly all plantings that are for the short term? You find bedding plants, house plants & some fast selling perennials in peat soils, all plantings designed to be on the shelf for a very short time.

The pine bark really is worth the effort to find. Of the 30 or so floral containers I still have in the garden, only two are looking shabby right now & it's because of my choice of the plant material mix & water requirements of two dissimilar plants in one container. The rest look as good as they did in June. I'm still cutting petunias & geraniums (in containers) back by the bushel.

Don't despair if you can't find the bark this season. It usually comes from southern yellow pine in your area (so it should be even more readily available than it is here - lower shipping charges to distributors too, so less expensive), or in more northern regions from hemlock, fir, or redwood. It is available somewhere near you. Keep looking at nurseries or even big box stores. I have found it at Meijer & at least 3 nurseries near me as well as two wholesalers where I can always get it.

I have conversed with (no exaggeration) easily several hundred people from the GW and even just from people on the net who have questions after reading some of my posts about soil. Many of them made radical changes in their container growing habits and a good percentage of them are now growing in a bark-based soil. I regularly get reports attesting to the degree of improvement in their containers & haven't yet had anyone say they like their old ways better. Perhaps there are growers that are disappointed with their results but are only being polite by not saying so - I can't say.

Having grown in commercial peat mixes for at least 10 years before making the transition to a bark soil about 12 years ago, I think I'm in a pretty good position to make comparisons and observations based on first-hand experience with both (and many other) growing mediums. The difference in growing in a highly aerated mix is stark, from both the perspective of ease of success and the possibility for plants to grow very near their potential genetic vigor. Something to consider: So far, the only ones that have stood up to pooh-pooh the use of a bark-based soil are folks who haven't (or said they won't) use it. ;o)

Al

Amy: I get my "pine bark fines" at Lowes here in North Carolina....they call it "Garden Plus Soil Conditioner". when you actually look at it, it is actually really fine pine bark mulch....works fine for me, and I think this is what Al is talking about.

Michael

Amy,
Michael bring up a good point. I don't think you'll find a commercial product labeled "Pine Bark Fines". What I use is Earthgro "Decorative Groundcover Bark", which I got at Home Depot. It contains some shredded wood in addition to bark, but I figure that's no big deal. They also make "Mini nuggets" which is about the same thing without any wood, but it costs around $5 a bag (2 cubic feet) vs $3 for the groundcover bark. I'm pretty sure either will do the job (Tapla, please correct me if I'm wrong). Basically, you want something where most of the particles are 1/2 inch or smaller,whatever it's called.

Bark is sold as chunks, nuggets, chips, mini chips, fines or other names. These names refer to the size of the bark pieces. Fines, often sold as soil conditioners (as noted by jmhewitt) are what Al is calling for in his recipe.

As a soil conditioner they serve 2 purposes. Initially they improve drainage and since they are so small they compost quickly and loosen and slightly enrich the soil.

When used as the basis of a potting mix they provide outstanding drainage properties, but do so at the cost of drying out quickly.

Al is quite right to place an emphasis on drainage, but when contemplating using a custom mix I encourage understanding the ingredients and what effect they contribute to the mix. Make sure it is what you desire. Superb drainage is desirable, but unless you have the desire and ability to water daily you might want to choose a base for the mix that retains water well while providing adequate drainage.

Great drainage is vital, but using a mix that needs to be watered more often than you can keep up with leads to dead plants.

I do want to be clear that I have no objections whatsoever to the mix Al recommends. None.

I do, however, think that people who use custom mixes without the knowledge of what the ingredients actually do are doing themselves a disservice in not understanding why the ingredients are what they are.

When one buys a bag of name brand commercial potting soil one is buying a product that works well for a large number of plants. If it didn't it wouldn't be popular. When one wishes to move beyond this 'entry level' performing soil mix it is very good to understand why one uses something different before one uses something different.

Too often I see people using a custom mix recommended by an author or other personality with no knowledge of what qualities the mix will have. The end result is often disappointment and then folks come here or go elsewhere and post bout how their mix dries out rapidly or has some other issue. Please, if you want to use a custom mix, do so, but learn what the ingredients are and what they are going to do before you go custom. Otherwise you are just taking a long road to using a bag of commercial potting soil.

Either way you don't understand what's in it or why and have no way of knowing whether ingredient a or b would better suit your purposes.

Again, in no way am I criticising Al's excellent soil mix. Rather I am trying to encourage those of you who are using his mix or anyone else's mix without understanding why the ingredients in the mix are what they are and what they do to spend some time learning this information. Once you understand this, you can evaluate recommended mixes for their suitability to your purpose and cook up your own with no trouble. If you don't do this you will find no end of soil recipes from various places all of which will convince you they are the best and that they are certainly better than commercial potting soil.

Reminds me of the mythbusters episode where they served TV dinner entries at a high priced restaurant and the folks raved about how great the food was. Perception isn't reality, but it sure does influence one's perception of it ;-)

Well, anyone who has been reading this board for any time at all knows that Al has explained--at GREAT length--the properties of each ingredient. He has even given different formulas for different types of plants, such as trees and other woody plants, because they require different properties than herbacious plants that are commonly grown in containers.

I have grown many different kinds of plants in containers this year in several different commercial mixes, Al's mix, and variations of Al's mix (based on availability and my own "hunches"), and have found Al's basic mix to be the best performing and most consistant.

Thanks, Al.

Amy, like a couple of others have mentioned, look for bags of soil conditioner. It's almost always pine bark fines. If you can't find pine bark fines and want to try a commerical mix for your veggies, try Metro Mix 300 if you can find it (usually it's at garden centers, not the big chains). Of all the commercial mixes I've tried, it's properties seem to best exhibit the properties that Al has championed. I have two bell pepper plants grown in it that are still producing, and have been since May. Had a couple of cuccumber plants that did real well, too.

I'm always as clear about the drawbacks as I am about the benefits of using a highly aerated (fast draining) soil. I speak often about how we need to consider the amount of time we can devote to watering our plants & the compromise we often make in a soil choice.

I noticed Username mentioned "... at the cost of drying out quickly." Our perspectives are just different. I perceive a soil that dries quickly as a good thing. Roots can't suffocate, root metabolism remains optimum, the entire volume of soil can be colonized by roots, gasses in the root zone are exchanged at each watering, etc.

My aim, when I speak of soils, is to let folks know they are not limited to a pre-packaged choice. The "whys" of component choices run all through my posts, so any seeking an answer to why they might include or reject a particular component are close at hand.

Container gardeners that are less experienced make the error of over-watering more than any other. For this reason, I think if I handed a new container gardener a bag of soil that is and will remain well aerated at the expense of having to water and fertilize more frequently, in exchange for his/her brand name mix, I would be doing a great service. It takes a greater degree of skill to grow in a marginal soil than it does to grow in a good soil and the potential for plants to show good vigor for extended periods is, of course, greater in a good soil.

I'm not sure I've heard enough to convince me that "... people who use custom mixes without the knowledge of what the ingredients actually do are doing themselves a disservice in not understanding why the ingredients are what they are." While it's true that they may be short-changing themselves if they don't make an effort to learn about soils, it's also true that we all establish our priorities; & learning about soils is probably not high on most lists. ;o) After all, how many take advantage of good things like refrigerators to keep food cold and micro-waves to make it hot without having a clue about the whys of how they work.

Al

I started writing this earlier in the evening, but got called away for awhile. I see Scott has posted in the interim.

Well, I have done a lot of reading (hence the overload) and my problem is not trying to understand what the ammendments do, rather trying to find the ammendments I think I'd like to use. I have called and then personally visited all the big boxes, two private nurseries and two wholesale suppliers and have seen nothing like the fines. Or soil conditioners. I even cornered a Scott's rep at HD today and asked him about such things. He said it was probably regional. But not here.

I did find one guy who could special order me the fines. Said he had done so for someone else a while back. But would have had to buy a pallet of them. That's 70 bags. Just can't manage that! So, I am settling for Jungle Growth, which seems to be the chunkiest of potting mixes. (I have been at every garden center, fondling the bags of this and that for several days now!) A close second was available at a private nursery, but the owner is a bit cagey about telling me what's in the mix. Bad vibe at that place...always has been.

So, I'm not really sure what is in the Jungle Growth either, lots of chips, some perlite and a bit of compost probably. Should I add more Perlite? I will put in some of my Fertrell organic slow release and some minor elements. I also bought agricultural limestone for calcium for my tomatoes. Anything else?

Thanks everyone for the continuing education!

I'd like some clarification from the resident soil experts on whether uncomposted bark should be used in container soil mixes. My understanding is that the decomposition process will tie up a lot of nitrogen, and that this in turn retards plant growth. Since it's hard to know how much nitrogen to add to compensate, I would think one would want to use composted bark. Comments?

You're right, Andy. Composted bark is better. I suggest fines because they are usually partially composted (I have a photo of the various barks I use if any are interested. The fines are easily seen as being partially composted) and nitrogen tie-up is less a problem than with uncomposted bark. When growers tell me they can only get small uncomposted chips, I usually suggest they compost over winter before using, but I regularly use uncomposted bark in some soils with no problems.

Conifer bark isn't as bad as you might think it to be. Pine bark usually runs about 300:1 carbon to nitrogen ratio. Sapwood products and chipped hardwood are usually about 1000:1 C:N ratio. Also, the high amounts of a lipid called suberin (often referred to as nature's water-proofing) in conifer bark make it extremely difficult for micro-organisms to cleave the hydrocarbon chains, so the little extra tie-up of N is worth the extra water and fertilizer applications I always mention.

It's no more difficult to judge the need for N in a bark medium than it is in a peat medium. Watch the old leaves, lowest on the plant. When they start to show the first signs of chlorosis (o/a yellowing or light-greening of foliage, beginning in oldest leaves & progressing to the younger leaves) it's time for a N application. If you're concerned about natural senescence (aging) of leaves, which includes yellowing, tug on the leaf. Leaves that are "dying of old age" will have formed an abscission layer at the base of the petiole & will release from the plant more easily than chlorotic leaves. This is a good way to estimate N needs regardless of what soil you are growing in.

Al

Hey Al, I get CEU's for this right? ;-)

I give up. CEU's?

Al

Continuing education units, I think.

Not never havin' much of an education, I wouldn't never of guest. ;o)

Al

You see, I am married to a physicist. I have always joked with him that I should be getting CEU's at the dinner table. Yes, Continuing Education Units...described on one website as folows:

"The Continuing Education Unit (CEU) is a nationally recognized method of quantifying the time spent in the classroom during professional development and training activities. The primary purpose of the CEU is to provide a permanent record of the educational accomplishments of an individual who has completed significant non-credit educational and career enhancement experiences."

Surely, my many hours spent here on GardenWeb must qualify!!

Amy,

I was at HD and Lowes yesterday. Both of their "regular" bags of pine bark mulch are much finer (maybe even finer than the "fines" in Al's pic) than they were earlier this year. I asked the lady working at Lowes if it got finer as the year went along, or if this is what one could expect for next year. She was under the impression that this is what once could find. Either place sells for about 75cents/cf.

This year, I bought my pine bark mulch from HD (Scotch Brand). The pieces were 3/4 to 1 inch big. I used them uncomposted and had tremendous growth from most of my trees. The difference between those that did very well and those that did well was the color of the container. White ones very well, black ones did well.

~james

Bumping an ancient thread.
I'm also having this same trouble. I've been to Home Depot, two Lowes, Ace Hardware and a large local nursery. No luck finding small pieces of pine bark. Anything that's small enough is cyprus pulp, eucalyptus or rubber, and the pine bark that's available is all nuggets.
Any new advice after 3 years? None of the stores I went to had any of the soil conditioners listed in this thread. Have things changed since then?
Thanks for any advice!