Mary, if you're going to be the city of Chicago proper and on the north side I got all my pine bark fines at The Farmer's Market on 4400 (something) north on Elston. That was the only place in the city proper that I could find that had this. I bought my last bags for this season there yesterday and saw they have about 1/2 pallet left. I don't think they're going to order any more of that this year.

I'm not exactly sure why these Smart Pots appeal to me, but I am a rookie just getting started, and have a twist on the questions posed above. I have a fully hardscaped front yard, 3-4" of pea gravel over landscape fabric over the native soil that used to be a grass lawn. I am looking to grow fruit trees in Smart Pots, placed on top of the gravel, and utilizing a drip irrigation system as much as possible. I will basically be following Dave Wilson Nursery's suggestions for Southern California for low chill varieties of peach, nectarine, plum, pluot, citrus, almond plus some blueberries, pomegranates, and passionfruit. If I buy 2-3 year bareroot dwarf trees, and have 20 and 30 gallon Smart Pots, what is the best growing medium to start with, Al's 5-1-1 or Gritty or something peaty? Also, would it be best to leave the Smart Pots on top of the gravel, or to dig the gravel away and have the pots directly on the landscape fabric, or even go as far as to cut thru the fabric and place the pots directly on the soil? Once I get the growing medium sorted, I will have more questions on watering and fertilizing, but I am trying to read more topics about those first.

"Is Sphagnum, reed and sedge peat the same stuff just more or less decomposted?" Wikipedia tells me "peat" is an accumulation of partially decayed vegetation or organic matter that is unique to natural areas called peatlands, bogs, or mires. One of the most common components is Sphagnum moss (Sphagnum and the peat formed from it do not decay readily because of the phenolic compounds embedded in the moss's cell walls), although many other plants can contribute, like ericaceous shrubs, and sedges. 'Phragmites' peat is composed of reed grass (Phragmites australis), and other grasses, and is denser than many types of peat. Peat material is either fibric, hemic, or sapric. Fibric peats are the least decomposed, and comprise intact fiber. Hemic peats are somewhat decomposed, and sapric are the most decomposed. I hadn't heard of the Von Post Scale until your post: A – Young peat, very light – Von Post scale: H1-H3 B – Standard blond peat, slight decomposition – Von Post scale: H2-H4 C – Brown peat, medium/advanced decomposition – Von Post scale: H3-H6 D – Black peat, very advanced decomposition – Von Post scale: H7-H10 E – Organic sediments and mineral subsoil From UC Davis's Peat Moss Fact Sheet, "Sphagnum peat can adsorb 20 to 30 times its dry weight in water, while hypnum peat and reed-sedge peat can adsorb 5 to 7 times their dry weight." Being in Sweden, you likely have access to different types of peat than we do in the US. Dale's been posting porosity data and moisture release curves of various substrates lately; if there's a way you could test the various grades of peat you have access to there, I'd be very curious to see what their actual characteristics are. If you're going to grow hundreds of bags, you might as well use a few different soil mixes, and see what works the best. Please take pictures and report back! :)

Comparing the gritty mix or 5:1:1 against soils such as those packaged with the Miracle-Gro label is like comparing grilled fish with raw veggies, steamed, to a double bacon cheeseburger with onion rings. Many will favor the flavor of the burger/rings over the fish and plant matter, but there's little question about which is better for the body. Extended intervals between waterings are a convenience to the grower, but a limitation to plants whenever it's perched water providing the extension. There's no judgement to be made if someone chooses the convenience over what will provide a much better home for roots, but there is no way to deny that the excessive water retention that provides those long intervals requires the plant to pay a price in the form of unrealized potential. There's a considerable margin for error built into the dosage suggested on the packages of almost all fertilizers. When temperatures allow (65-75* range), I fertilize plants in both gritty mix and 5:1:1 at 2 tsp of 9-3-6 per gallon at weekly intervals, the result being very strong growth; and, so far I have observed no indications plants are having difficulty tolerating the more concentrated solution. During the winter when my trees are under lights, I had been fertilizing at every watering with 1/4 tsp/gallon of r/o water. I got a LOT of winter growth, but it was rank growth that had no place on trees that are being worked to increase ramification (more fine branching and smaller leaves). I decided to try fertilizing every other time I water at the 1/4 tsp/gal, and that seems to work well. I'm not getting as much growth, but my trees are packed so tight the shade produced by excessive rank growth is a major problem for me. If you're using a fast draining medium, you have lots of options and near total control over what your plants get and when they get it. If you are using a medium that precludes flushing the soil when you water, the job gets much tougher and the kind of control you might want to enjoy just won't be there. It's very important that you are able to flush the soil w/o the planting remaining saturated for extended intervals because the saturation affects root function/health. Al