Depends. The bagged pine bark mulch which is small chunks mixed with shredded bark will, large bark mulch will fill around the chunks and not add very much drainage. The smaller chunks and fines with more irregular surfaces and more surface area provide passageways for better drainage and a looser mix.

bkay, it does for the first year and then in my experience it seems to decompose pretty quickly.

My experiences here in the UK are going to be way different to yours I'm sure.

I'm not familiar with Miracle Grow potting soil, what does it contain? and what ratio are you using?

I mix my own 5111 which is slightly different to some I've seen promoted here. Thats 5 Pine Bark Mulch/Chippings, 1 Peat, 1 Perlite/Vermiculite depending on what is cheapest and 1 John Innes No2 Potting Soil plus a measured amount of John Innes base fertilizer.

Certainly the next time I pot up all but the largest pieces of bark are gone.

We get a lot of rain here all year round. I think even though it drains well it has an effect, compressing the mix and breaking down the bark.

I imagine you must be watering constantly to keep your plants going.

Do you think this could be the answer?

Dave

be nice to SEE .. what you are actually using ... it comes in all sizes.. shapes.. forms.. etc ...

you would probably be surprised at some of the chunks chris uses ... i mean huge ...

i havent seen many reviews of MG media ... cant you track down promix BX ..???

https://www.google.com/search?q=promix+BX&ie=utf-8&oe=utf-8

some guy down the road sold me mine ... it stores dry.. in a garbage can.. for about 4000 years .. lol ... so go large ...

i though lowes carried it at one time ...

ken

What factors do you use to determine good drainage? My thought was if you water a pot where the media is pretty dry and it quickly starts pouring through the drain holes then you have decent drainage. I see all of the conversations here so I guess there's way more to it than that. In my three month period of 95-100 degree weather I was thinking that I didn't want a media that dries out too quickly, but then again there is the cooler weather times to figure into that.

If it is off and on rainy with no or little sun for an extended period I don't think any media is going to try out very quickly no matter what it is composed of. You mentioned having a rot problem this spring on the other thread. As you are in this unusual extended rainy period along with a pretty wet winter I wonder if that is as more of the problem for you that your drainage?

I started mixing one part expanded shale to five parts potting soil in my pots this year.

This jumped out:

" I've been mixing the bark with my regular Miracle Grow potting soil"

Are you using potting SOIL or potting MIX? Potting SOIL needs to be hugely amended before putting it in containers (IMHO) and even potting MIX needs to have some amendments because over a season it will become completely compacted and cause root issues.

I lost so many nice plants because I had them potted up last summer in MG Potting MIX (was planning to move, ended up staying in the house) and left them in them over the winter. That said I do know it is possible to keep hostas going nicely in containers for at least a few years before you need to refresh the container medium. I am going to try Al's Gritty Mix with a few to see if they do better over a winter. I know Al's Gritty Mix is touted highly in the Container Growing forum and I use it exclusively for my citrus trees.

Here is a link: http://forums2.gardenweb.com/discussions/1382584/als-gritty-mix-a-learning-experience

Good luck!

Alexa

Good explanation. Thanks, Ken.

he's backkkkk ...

i said: and become boggy ... so you put in large particles of things... to create air pockets...

==>>> and when you get to that part of the equation ... it can be just about anything ... one guy i knew used chicken grit .. only problem.. his one gal pots.. were like 20 pounds each.. but he said.. well.. they dont tip over in wind.. i said how do you avoid herniating a disc when you move 100 of them ...

some use perlite to excess [and trust me.. thats not good ..lol].. wood chips ... bark fines... there is simply a myriad of things you could use ... but go large.. rather than small ...

you are just looking for something somewhat light weight... and yet somewhat large in size ... comparing to media particals.. dont go all literal on me ...

thx santa for actualy saying it ..... i am getting real tired of the LIKE and THANK YOU Button replies... GW used to be a conversation .. now peeps come in.. and cant even type out THX and hit send ... and its pissin me off ... but i digress...

ken

lol

Ken-san ;-)

Yes - I am adding chicken grit as prescribed in Al's Gritty Mix - works wonders for the dwarf citrus.

Alexa (who just picked up a large bag of pine fines and chicken grit at the local feed store)

When you say large, how large? This is a conversation that has been beaten to death in the last year+ since I've been on the forum. Lots of people with lots of thoughts on it. I think maybe it falls into the "whatever works for you" category.

whatever works for you

==that is the bottom line .. as long as you understand the variable.. and.. DO SOMETHING.. to address it ..

ignore at your own peril ...

hell.. you could probably use grandma old hair curlers.. lightwieght.. large.. add iron to the pot.. lol ...

ken

Ive started to use Napa Floor Dry(8822) 100% calcined DE as an additive to my soil/media mix. Still working on the exact portions but its cheaper than perlite and vermiculite and helps a lot with drainage and excess water retention issues.

Precisely! Turface is the other additive I often incorporate depending on what I can find and what is cheaper.

Well, it's not working for me.

No, Caliloo, I am not using dirt. I am using Miracle Grow Potting Mix about 1/2 and 1/2 with the smallest pine bark I can find. There don't seem to be any sources for pine bark fines around here.

It just doesn't seem like I should have plants I bought in 2013 rotting. Maybe if they had been in the same pot for years. That would make sense. I am losing OBL and Elegans that I just purchased in 2013. I did not bare root them, but just up potted them a little as they were in nursery pots. Francee is even rotting. I didn't think you could kill Francee with a stick. All three of those had really wet, dense media when I dumped them, as did Paradigm.

I'm not sure the roots died from rot, though. You would assume so. It's not southern blight, as there are no little orange balls. The roots that remained were small and stringy.

Another thought came to me. When I dumped the pots, I noticed one had salt build up. What made me think of it was when Babka said she had to soak hers and wash the salts out like I used to do when I had houseplants. We had a dry year last year and most of the water came from the hose. Usually, we have a fairly good rain amount of rain, so that keeps them washed out. Also, our city water is very alkaline.

BUT, I have 70 or so pots and just a few seem to have the problems. I can't blame it on the theory that they were expensive, so they die. Francee was cheap.

Santa, the ones that are rotting have been protected under the overhang of the shop. They haven't been sitting out in this lovely wet weather. (I'm not sure we are out of drought status permanently, but our lakes are overflowing.) I figured I couldn't lose anything, so I set them out in the rain over the weekend.

Ken, yes there is a local source for that Promix. Which one do you use? They are not close to me, but I'll drive a few miles to feed my addiction.

Thanks for listening and for all the help.

bk

You've been at this for a long time, bk, and I'm sure you know these things but I have to ask some "well, duh" questions.

Did you sift the bark to remove the smallest pieces(under 1/4 inch or less)?

Did you avoid putting pot shards or gravel over the drain hole because you know it really doesn't improve drainage?

Was it really salt build up or fungal hyphae from the bark (actually a beneficial thing)?

The more consistent the particle size in a mix, the better the drainage and I fear the dissimilar size may be a factor. Here, in my zone 5, I'd add at least as much perlite as the pine bark. In Texas, perhaps less. Turface will hold moisture and I'd avoid that for now with a peat based mix.

Pro-mix BRK is a peat/pine bark combo.

tj

No, I did not sift the bark.

I don't know about the salt build up question. There was a white substance on the pot, at about the soil level, in the pot when I dumped it. I assumed salt. Is that a fungus?

But TJ, I'm really ready for a ready made mix. I've switched what I've been doing several times and I don't remember exactly what I was making or doing at that time. The results of a certain mix are often years away. I'm ready for a consistent product and I'm not producing a consistent product with all this mixing.

Does the Promix meet that kind of specification?

bk

I've only heard good things about Promix. I mix my own, so no firsthand experience. The one I noted may not be good straight and might require more components. Hopefully a Promix user will chime in with a ready-to-go variety.

If the white was just on top then it was likely salts.
Just an FYI- I asked about sifting the bark because you want to sift out the tiny stuff.

tj

i like the promix but it is VERY DIFFICULT to find. I bought the last bags in the DM metro area and now have to go to KC area to find it. I use it in the 511 so it only uses a '1' in the soil cocktail concoction.