I never used it as I could never find pine bark fines. Must be good as Tapla swears by it. I wonder maybe a rolling pin over bark would work? Just kidding but some kind of grinder maybe? If so what kind? Possibly fines are available somewhere but where? Stuck in trying to use his mixture!

I don't understand why pot mixes have to be soil-less. I use a mix of peat, vermiculite and top soil and my plants have always done very well in their pots. When I potted up some seedling trees I used top soil and pine shavings. They loved it.

Carol

I too have read about "soil-less potting mixes and custom mixing your own. But I do not have the time nor the space to mix my own potting mixtures. I use plain old off the shelf potting mixes. I have always used MG potting mix (not moisture control) with great success. This year I am trying the Lowes brand of potting mix to see how the roses do and so far so good. The Lowes brand does have some mosture control but not as much as the true MG moisture control Lowes brand moisture control.

I have also heard and seen mixing potting soil with aged horse manure (50/50) is also a great mixture.

Also each winter I top layer each pot with organic compost to help feed the soil and fertlize with natural/organic products)

Liz

To get bark fines, buy the cheaper grade of pine bark (not the carefully screened nuggets) and shake it through a 1/4" mesh-- or just pick out the big pieces.

Doesn't Al at the Container Forum recommend a mineral ingredient such as Profile or Schultz Aquatic Plant Soil for semi-permanent woody plants such as roses? This is a porous ceramic, like cat litter but fired to a higher temperature so it can't melt. It retains nutrients and never breaks down.

I suspect all-organic or soilless potting mixes are used in America because they are cheaper to ship (being lighter) and consumers don't like to mix dirt. Europeans generally use homemade mixes that include about 1/3 mineral loam soil with sand (or other lightener) and organic matter. In effect these mixes are light sandy loams.

Ah HA! I knew it!!!

Well, I think I'll stick to what I have then!! It seems like a huge deal to find the fines, etc. I feel better now!!

Liz - compost is good too! Well good, Again I feel better! :)

CArol

The problem with soiless mixes, especially ones with peat moss, is that once they dry out completely, it is near impossible to get them completely wet again, especially the inner core of the plant. Mixes containing sand can be very heavy to carry around once the pot is completely wet...

Plants are happy in most mixtures as long as they stay moist...

Thanks Decobug!! They seem pretty happy! Watering is part of the fun, so I won't let them dry out.

Carol :)

The value of pine bark is that it is the most durable organic material you can use in a mix. It's chunkiness, which preserves air spaces, can last 5 or more years. Manure and compost either are, or will soon become, fine-textured muck that doesn't drain well and doesn't aereate until it dries out.

michael - How does it provide nutrients? Is it all in fertilizing? Does the pine bark provide enough stability to the structure of the rose during high winds? Do you use it? All in all I'll look for it next year and plant my new pots with it as a comparison. Thanks!

Carol

I've been using Wal Marts Expert potting soil for years. When Wal Mart runs out I'll go to Lowes and get their jungle potting mix. Have had great success using both with almost all my plants, especially the roses. I use a combo of pine bark, pine needles and oak leafs as my mulch. Throw some Black Cow on everything a couple of times a year. I use a lot of organic mixed with a little chemical fertilizers and I water a LOT. By the way, I exhibit and have been very successfull over the years using this soil mixture and mulch.

Canadian Rose,

Al's (tapla's) recipes contain around 50% pine bark, not 100%. His mixes are lightweight when dry. If you think more weight it needed for stability, you would add some sand or mineral loam.

For practical purposes you would consider bark non-nutritive, though eventually it becomes compost. Al incorporates coated, timed-release fertilizer and a micronutrient supplement. Or one could use Rose Tone etc.

I don't go in for container gardening and don't have any consistent practices. However, when I had a batch of potting soil a while back that I judged not chunky enough for big pots, I added 40-50% pine bark fines, and the results were very good.

Several years ago, I grew 7 roses in terracotta pots on my deck for 3-6 years. I used a Gardner & Bloome potting mix mixed with some sand and vermiculite.

Over the years, my roses deteriorated in this mix. Every time I'd turn around, there would be some ugliness in the leaves I'd look up in one of my many books -- some nutrient deficiency or disease. I learned about pH and started testing. My potting mix would be way too high pH, then I'd amend it with some recommended thing (coffee grounds, earthworm castings, earthworm casting 'tea', Dr Earth something something, Roger's Soil Activator, etc etc etc), then the soil would be way too low pH. With the resulting nutrient deficiencies, the roses were extremely vulnerable to diseases and insects as well.

I could easily say I grew roses with success, though, because during these years the roses were alive and produced some blooms. HOWEVER, when I read Al's observations about the drawbacks to potting mixes, I recognized the problems I have had. When I had my best results with potting mix, it was when I repotted EVERY YEAR. This was a huge pain to do with large heavy terracotta pots and roses, especially after I injured my back. So then when I didn't completely change out the old, spent, compacted soil every spring, the roses deteriorated: they had more nutrient deficiencies, more diseases, uglier looking leaves, and fewer blooms with each passing year.

Another (less important) problem with traditional potting mix was that brown organic sludgy stuff would continually drain out of the pots. If I let them drain directly onto the deck, the sludge would stain the deck and make a big mess. So I elevated the pots on feet and put saucers under them. Then at least the sludge was confined to the saucers. But it was always unsightly, growing algae and who knows what else.

It sounds like if I use the gritty mix, I can get several good seasons of growth before I have to change the mix in the pots; changing the mix will be much easier without the slime in the bottom/cement at the top; the pH of the medium will be much more stable, therefore easier to continually provide the optimal levels of nutrients throughout the changing temperatures of the year.

Al says that when using traditional potting mixes, the plant has a period of doing well right after being potted in fresh mix, and then slowly deteriorating. This is exactly what I have experienced over years of growing houseplants indoors and roses outside. As long as I managed to repot or pot up every plant every year, plants survived and even grew, but with roses, repotting every year is just not something I want to do.

I have roses in pots. The first year I made a mistake and used compost! I didn't realize..anyway this year I am using a rose mixture and putting quite a bit of peat moss. Drying out isn't as big a deal for me as I am in the Seattle area. I put about a handful of a mostly organic rose food in each pot. I will keep you posted on how it does. I am not going to strain pine needles or something!

I have used "Al's" mix for many years. For the pine bark fines I just use pinebark mulch, not the nuggets. Works fine. Perlite can be bought in big bales. Either order through your rose club or try and fine a busted bag that weighs about 400lbs (absorbs moisture.)

When it becomes soup you can get another year out of it by adding some more pinebark, the next year, however, it goes into the compost pile.

Theoretically I might doing everything totally wrong, so pay no attention to what I do in terms of advice... I just thought you might be interested to think that there might not be a single formula to shoot for that everyone must go by.

I have for the longest time understood that you were supposed to purchase potting soil because pot conditions are so different from ground conditions, and that for some reason sterile dirt was supposed to be ideal there too. I'm not into sterile dirt, though, and kind of like the idea of letting whatever beneficial organisms might be present in the soil do whatever they might want to do. Anyway, the only adjustment I've made to the kind of soil I put into a pot vs. what I'd put a rose or other plant into in the yard is to provide a little more sand or coarse bark, especially at the bottom of the pot. I've put all sorts of organic matter into the mix, especially leaf compost (with, I suppose, all those fungus diseases present there). For the roses, the mix is heavy on alfalfa, with a good bit of cutup banana skins too, and some bone meal thrown in to help the leaf mold component that's mixed in with the clay, sand, and woods topsoil mix. (I've never had the problem of a clay and sand mixture clumping into heavy impenetrable bricks, given all the organics mixed in with them.)

The roses seem to love the dirt they are planted in, and my houseplants do too. For the houseplants, I just keep adding more dirt on top as the organic components of the dirt in the pot decomposes enough to lower the volume of dirt. I haven't repotted the houseplants in more than 30 years, except for a few that weren't planted in large enough containers to begin with. Though I know you are supposed to repot houseplants, I don't do it. It might have made a difference that during most of those years, the houseplants were watered using well water, not treated city water. The roses here are all watered using well water too.

I haven't been into roses long enough to need to repot any yet, other than to repot to a slightly larger size what arrives from the nursery in a one or two gallon container if the spot in the ground isn't ready for planting them yet. Mostly all the roses will end up going into the ground, but those in pots for now really do seem to like their mix; growth is good and their leaves are a healthy green. We don't have any roses that are disease-prone varieties, and the potting experience thus far is with hybrid musks, floribundas, and polyanthas.

Best wishes,
Mary

I have lots of roses in pots and just use a good quality potting mix. I just use the normal fertilizers that I use in the ground (the measurements are diff for pots, I follow the packet instructions) and give them more or less the same treatments (fish emulsion, seasol, alfalfa tea, etc). I do not mix compost in the pots. My roses in pots actually have done very well. I have had them all under 2 years so probably might need to change the mix sometime in the future. But at the moment they seem to be growing better and better every day.
Cheers,
Sanju