I'm waiting for comments on your post because I would also love to know what I should use to fill my new large pots..I've heard no native soil, garden soil or compost but use a bark based potting mix..have you heard similar thoughts?..

A bark based potting soil mix - like the 5-1-1 mix referred to frequently on this forum - is ideal for just about anything other than cacti and succulents. And yes, you want to avoid using garden soil, topsoil, raised bed soil or compost in any significant quantity as they will adversely affect the very fast drainage that is required for container plantings.

If the containers are deeper than necessary for best root growth (most plants will have roots that focus in the top 12 inches or so, often less), you can fill the base of the container with something to take up space other than the more expensive potting mix - plastic water bottles, crushed pop cans, styrafoam peanuts, etc., but be sure to use some sort of barrier, like landscape fabric or weed cloth, to keep the soil and the plant roots from migrating into these fillers.

Nicholsworth, I've been searching the internet and gardenweb. There are a lot of different medias suggested. Many people grow vegetables or annuals which is very different from growing perennials.

It is difficult to find the information that we are seeking. Unless you search for the exact words used by someone posting on a similar issue, you just can't find it.

As I did some reading of old threads, I learned from "tapla" that if the container is too deep, you can put large bark nuggets to reduce the depth of the media. I also found a thread where Al (tapla) suggests to another forum member that he has a "recipe" he uses for large containers. He did not give specific details but asked the forum member to email him. Here is what he said:

"If you decide you'd like to build the soil, I'll send you a photo of the soil I have in my raised beds. It is a mix of pine bark, peat, swimming pool filter sand, crushed granite, and Turface (a baked clay granule). The soil is 5 years old and yields fantastic growth and offers great aeration and superb drainage with very good water and nutrient holding ability. I've done nothing to it since building the beds 5 years ago aside from side-dressing the plants in it with Milorganite periodically. The only component that would take some searching is the Turface, but there will be several places near you that sell it. The components are all inexpensive & the soil will likely end up costing the same as or a little less than the commercial mix you're looking for."

I found that very interesting. I would love to have that recipe!

Gardengal, I have been stressing about what to fill the containers with! Time if marching on! I did consider that the 5:1:1 may just be the best option. I am glad you also agree! Only thing is that bark fines are not easy to find here. I am glad you mentioned about options for filling the bottom of the container!

newhostalady..who knew that filling a large container would be such a hassle?..I would like to avoid tracking down all the components to mix the right formula..is it too much to ask to buy a bag of potting mix and dump it in?..

That quote from Al refers to raised beds. These are not the same as a container and do not require the same sort of media - the two products are NOT interchangable.

Unfortunately, commercial producers of most potting soils have not seen the benefit of bark based mixes. Most tend to be peat based. These tend to be excessively water retentive and of too small a particle size. While they will work perfectly well for awhile (maybe as much as a full growing seaosn), they will begin to compress and compact and lose the aeration and fast drainage container gardening requires. This then leads to a higher and higher perched water table and the incidence of root rots.

So sure, you can just go out and "buy a bag of potting soil and dump it in"! It will work for a few months but eventually you will have a soggy, gooey mess and unhappy, unhealthy plants and you will need to start over again with a fresh mix. Take this advice from someone, who like Al, has about 60 containers of all different sizes, indoors and out, with both permanent and seasonal plantings, and has learned the hard way, over time, what works best :-)

I realize a raised bed with ground contact is different than a container with drainage holes..I have a few stone retaining walls where the plants are growing in raised earth..we used the soil from excavating and filled it in..and we compost so I used a top dressing of compost after planting..I didn't buy any soil to use for fill dirt..but I need something different for the pots..

I hear what you are saying Nicholsworth. I feel the same way.

That Organic Miracle Gro looks like a good product.

Gardengal, in regards to the quote, Al is not referring to raised beds. The post was asking for media for a large wooden planter. I could post a link to the thread if you like.

In regards to everything else you said, I agree!

There doesn't seem to be a bagged mix that will work well. I think that that is the case because most people are using the media for the outdoor growing season only. We are not supposed to be overwintering our plants in pots and containers! And that's a whole different ball game!

"We are not supposed to be overwintering our plants in pots and containers! "

Really?? Who says? Huge numbers of gardeners grow almost exclusively containers....simply because they have no or very limited garden space in which to plant. What about all those inner city urban dwellers that have only rooftop decks? Or those who rent but still wish to garden yet not spend al their time, effort and $$ on someone else's garden? Or those who grow tropical or very zone tender plants that won't survive inground? Or bonsai enthusiasts? Or all the many millions who grow houseplants??

There ARE a few decent bagged mixes on the market that are bark based. But they are not widespread in their distribution and are expensive. For most folks it is easier and cheaper to find the raw ingredients to make your own. And that way, you know exactly what you are getting.

newhostalady, Al's quote specifically refers to a mix he used for his raised beds. I've known Al for nearly 25 years and feel quite certain he would not suggest a raised bed mix for a container situation. They are two entirely different conditions that call for different media - you just don't need an engineered soil media for a raised bed (but you do for a container). Plain old garden soil enriched with some OM works perfectly well in any bottomless raised bed. The same soil will provide lousy results in a container!

newhostalady..did someone already mention these?..seems a little familiar..available at Home Depot it said..I don't know anything about them..all 3 formulas say "containers"..don't know what's different about each one..

The Kellogg's soil products referred to above are actually one of the few bark based bagged soil products I recommend. I am very familiar with the company (they are local) and they sell under 3 different brand names with 3 different price points (and to 3 different types of retailers). I often use one of their bagged soils myself (not one the 3 shown, however) and have found it a decent product providing good results.

Of the three different bagged soils shown, I would stick wth the Patio Plus. It is closest to the 5-1-1 soil mix in its formulation and will hold up moderately well for at least a year or two before requiring replacement.

gardengal..good to know..sure would be easier..

Nicholsworth, I have not seen one of those bagged mixes in person. Probably not a product in Canada. I am glad Gardengal has some knowledge of them.

I don't think Al (tapla) is saying that the other kinds of media don't work. I read his comments about how his mix will last longer and resist compaction for a longer period of time. Who wants to amend soil after a year or two?

Say you decided to plant hosta in a large container with a good bagged media. Al says the media will compact sooner (than his suggested media) and lose the air porosity plants need. The soil level in that container drops. If your plants are not that big, you can remove them and add more media and replant. You wouldn't be able to just top up the container with the plants in it. Most hosta would not be forgiving of that.

Al (tapla) also says from all the variables---sun, water, fertilizer, drainage etc.---drainage is the one element most difficult to amend. That is why his media recipe stresses drainage.

Gardengal, when I said "We are not supposed to be overwintering our plants in pots and containers!" what I meant was that I FEEL like I am not supposed to be growing in containers and overwintering. And most certainly not with Al's gritty mix or 5-1-1. I feel like that because (1) I have never found pine bark fines in my area or anywhere near it, (2) I would have to travel 70 km to purchase Turface and (3) I have never found a bagged product made for containers with enough bark or the "right" kind of bark. So that makes me feel like I shouldn't be growing in containers.

"Al's quote specifically refers to a mix he used for his raised beds."

Let me know if I misunderstood. Here is the link which will bring you to the thread I am talking about:

https://www.gardenweb.com/discussions/1418502/best-potting-mix

After rereading it again, Al does mention that he uses the mix I mentioned above for his raised beds. But it sounds like he is suggesting it to Carrie for her planters.

By the way---if you have known Al for 25 years---where did he disappear to?

"By the way---if you have known Al for 25 years---where did he disappear to?"

He hasn't disappeared at all :-) Doesn't post as much on the CG forum (was hounded there by trolls for a while and I think he just got fed up) but he is still very active on the Houseplants and Bonsai forums. Occasionally on Citrus.

That really is a shame. Some people spoil everything for everyone else.

Nicholsworth, what size containers are you considering for planting?

I used the Kellog's Patio Plus, and was not too happy with it. There was a fair amount of bark, but a lot of "dust" that settled to the bottom and turned the consistency of chocolate pudding. That being said, I'm one of the lucky ones that can buy all the ingredients for 5-1-1 and gritty mix at one store, about a mile and a half from my house.

That being said GardenGal says it is a local company, and I'm on the east coast, so the product I get might have been made here on the east coast, and might be vastly different from what you may find on the west caost.

Were I not able to find the 5-1-1/GM components , I would consider using the Kellog's, but I would sift out the dust, and put 1-2 parts back in.

You make a good point about sifting out the dust mblan.

You are very fortunate to be able to purchase the ingredients for 5-1-1 and the gritty mix in one store!!!! What kind of store is selling all those ingredients? I'm so envious!

newhostalady..I have 7 new containers..4 different styles..all are 15" to 17" wide to 15" to 20" tall..not the biggest pots ever made but good sized and it will take quite a bit of potting soil to fill all of them..

Are your pots the blue ones and the ones your husband was going to drill holes into?

From what I remember reading (tapla's posts), you have the option of putting water bottles, styrofoam peanuts or bark on the bottom of your pots instead of media. Stryrofoam and bark are lightweight. If you want more stability for the container, tapla says you can fill the water bottles with water and a bit of bleach. That would make your containers more bottom heavy. Then fill the rest of the pot with media. I think the 5-1-1 might be a good mix for your containers. What do you think? Or do you want to experiment and use different media?

nicholsworth, that looks like a very decent base for a good potting soil mix. But rather than adding peat to the mix, I would have added perlite or pumice. The added peat will decrease porosity and fast drainage whereas the perlite/pumice would increase it......a much better end product.

Yes..the blue ones in the pic are some of them..the black ones were emptied and drilled and are still empty..it took awhile for the soil I dumped out of them to dry out..I dumped it into 2 blue ones..just partially filled the blue ones..did it that way so they could dry out..the raised bed mix does remind me of the MiracleGro mix I used years ago..we'll see how the plants do..

gardengal..I'm glad you think it looks decent..I'll keep the perlite in mind..I used a very small amount of peat..just 2 handfuls..one at about halfway full..mixed it in..and mixed another handful in closer to the top..

Nicholsworth, I missed seeing the picture with your pots! I love elephant ears too!

Looks like you and me are learning a lot about container mixes! I think the larger the container, the more difficult it will be to mix media for it. But it will be an even bigger job to amend or replace the media in this 4 foot wide planter or any very large container.

Thanks gardengal for all your help!

newhostalady..I've been thinking about potting mix for weeks!..and I'm getting tired of it Lol..I'm need to empty the bags and try what I bought!..my husband said "you know these bags and pots are everywhere and it looks awful"..good luck with your planter..post pics when it's finished :-)

Nicholsworth, you really do sound like me. I've got bags of media and pots everywhere too. And my husband is complaining about it! My planter has been delayed. My husband hurt his arm. Not sure whether he can complete even one of the three wooden planters before fall (which may be too late to get the media and too late to plant).

You're funny mblan! I wish you more luck in love and money!

My husband may be able to complete one planter this month. My plan is to do the 5-1-1 mix. But as I stated above, I cannot readily get bark in the appropriate size. So I could get the smallest sized bark I can find and use that. I guess this is going to work out as an experiment. It's a heck of a lot of media to use as an experiment! Another concern is that the plants will go from in ground to 5-1-1. I don't think it will be enough time to settle themselves into this new mix. Maybe I should leave the container empty this winter and plant in the spring. Looks like I have a lot to think about!

I'm in the same boat!..I wish I could turn back time..some of my pots will be ready and waiting for spring..rain yesterday and for the next 4 days so it's not likely that I'll get much work done..working on big pots in the garage is so messy..so much easier outside..so until the rain goes away I'm inside reading lol..

Still continuing our heat wave here. Now the unsettled weather is coming with risk of thunderstorms. I don't know if the larger bark pieces will work for this container. I think I would be more successful if transferring potted hosta in the 5-1-1 already and placing them into the new container. That's just my gut feeling. Not sure what I will do.

Hopefully the weather will improve for you and you can get back to some serious gardening!

I actually used pine bark mulch and simply mixed it with fairly decent potting soil. I literally had to read the ingredients on all kinds of brand for potting mix before I think was the best. I simply went with 5 parts pine bark mulch and one part potting soil. That was for trees in 1-15g pots and they seemed to do fine. This is the most minimal effort I have done and I've been doing Al's 5-1-1 for a long time but it got to the point that it was just too time consuming trying to find source for the best stuff with a full time job and family so I just simply went for the easy stuff as long as you understand Al's reasoning behind 5-1-1 mix. Avoid too much peat moss no matter what. I know it seems like I have to water them everyday in the summer in Texas but that's what they like...

lou spicewood: what kind of potting soil do you mix it with?

The brand is Sta Green. I mainly looked for higher content amount of pine bark fines along with peat moss and perlite. Just have to look at the ingredients and look for highest amount of pine bark fines and mix it with bigger pine bark mulch ones. Lowe's hadn't sold Landscaper Mix in a couple years which is mostly pine bark fines with a bit of perlite. I did have to sift out pine bark dust but I liked it the best but they pretty much stopped selling it forcing me to find alternatives...

Your mixture seems good lou_spicewood. I just want to mention (to others) that we need to be aware of the zones that we are in. What might work in one zone may not work at all in other zones. It also depends on what plants will be in the container.

I'm still around. The 2 overriding reasons I don't post as much here A) my brother partner is critically ill and hasn't worked since last Oct, so I've been working long hours to compensate for his absence; and B) there are a number of very knowledgeable container gardeners at this forum whose advice can always be relied on. They catch and correct a very large fraction of the advice that might be considered myth or simply wrong. A man more wise than I, Robert Ingersoll, posits: "The destroyer of weeds, thistles and thorns is a benefactor, whether he soweth grain or not.", and I've found that to be true, over and over. I sort of don't mind dealing with the trolls because they aren't doing themselves any favors with antics that naturally establish a pecking order, and, there is a lot of good information that comes from disagreement. I love it when something they say provides an opportunity to expand on why a POV/opinion is wrong.

Not sure what I can add here to help, but I will say that large containers that have perennial material in them (trees & shrubs are perennials, too) will suffer a lot of shrinkage over time as the organic fraction of the soil breaks down and gasses off or is flushed from the soil. For that reason, I think a medium with a large inorganic fraction (like 75% or more) would serve best. If that's not in the cards, then a bark-based soil is the next best bet.

Ballast for the planters that are essentially containers will work very well in controlling excess water retention, but you still have a compaction issue to consider.

I hope everyone is having a good weekend.

Al

Thank you so much Al for weighing in! I am sorry to hear that your brother partner is very ill. It sounds like a difficult time for you now, but it looks like you are coping as best you can.

I am glad that you can see something positive in regards to the trolls!

As my container is very large, 4 feet wide x 2 feet deep x 2 feet in width, I find it rather daunting to come up with a "recipe" to fill it. (In other words, I am scared to death!) I would really like to try a more inorganic media (as you mentioned) but am lost as to what proportions to use. Can you help?

I am able to purchase:

Turface

Granite (#2 growers or hen grit which is a somewhat larger)

Swimming Pool Filter Sand (probably---Is there only one size?)

Peat

Pine bark (generally in the quarter size (25 cent coin only)

Here is my planter which is almost completed.

I am eager to plant perennials in this container!

I am gardening all this weekend. What could be better! Hope you all are having a good weekend too.

Water perches in soils when there is a layer of soil with particles more than 2.1x the size of the particles in the layer above it. An example would be water perching in silty loam situated above a layer of coarse sand mixed with gravel. You can actually approach this using a couple of different strategies, but I'm wondering if the planter will sit on the deck, and, if so, is the deck reinforced to handle the weight?

If it is, you might consider layering the soil like this:

6" of 2 parts of #2 granite and 1 part bark (granite: grower grit or #2 cherrystone if either are available)

6" of equal parts of unscreened Turface, granite, and bark

6" of equal parts of unscreened Turface, granite, bark, and sphagnum peat

6" of 2 parts of unscreened Turface and granite + 1 part each of bark and sphagnum peat

After you lay down the first layer, smooth it out and add 1" of the next layer and scuff up a bit and mix it into the top 1" of the lower layer. Repeat as you work through the layers.

If you wanted to use ballast, you could use a more water-retentive soil, but the ballast would reduce the volume of soil available for root colonization, a blessing or a scourge, depending on your perspective.

Al

Wow! Oh my goodness, what a "recipe!" I am so impressed--- and blessed to have your help! Truly!

The container has a bottom because I desperately wanted an area where no roots would invade! I am so, so tired of tree roots limiting growth or stunting growth in my plants and also compacting my soil! That was the whole reason for the planter. (Please don't tell me to cut down the tree/s. That is not an easy endeavor.) I had not seriously considered what the media for it would actually be. Silly me!

The planter is to have legs to help with drainage. Underneath would be concrete slabs. The concrete slabs will be placed on soil, not on the deck. I suppose the legs could be eliminated. Also wanted to put foam insulation around the inside of the walls of the planter to try to moderate temperatures of the media but not on the bottom.

I went out to measure the planter and found that the working inside area will be only 15 inches in depth, not 24 inches.

If the planter has a bottom, then it would require a different "recipe?" And if one does these layers, don't they get all mixed up when planting? Or are we trying keep these layers intact? The larger pieces of pine bark (25 cent coin size) will work for this recipe?

No ballast, I think.

For 15" depth, change the ht of the layers to 3,3,3, and 5" respectively.

It doesn't matter if the planter is on legs or a concrete slab, water retention and drainage will not vary so you could notice.

If you set the planter on a slab, you'll gain some geothermal heat through the bottom, and you can retain some of it by way of the insulation at the sides and by mulching heavily for the winter. If you set it up on legs, you might as well not bother with the insulation. You'll have eliminated the heat gain via conduction through the bottom of the planter. While the insulation might cause a lag in how fast the soil temperatures move upward and downward in the planter, it won't offer enough protection against ambient temps of say 0*F to save plants for which that represents a killing low. In order for insulation to work, you really need an extraneous heat source you can trap in the planter. Example: Take a plastic cup of water and put it in the freezer. At the same time, put a cooler with a plastic cup of water in it in the same freezer. Within 3-4 hours, the cup alone will have reached the same temperature as all the rest of the freezer's ingredients. The cup/water in the cooler that's in the freezer will take much longer to freeze and to reach the same temperature as the rest of the freezer's stores, but within a day or so, it will be the same temperature as the frozen water in the cup that's unprotected by the cooler. Wire a small light bulb so it's inside the cooler (an extraneous heat source), and the story changes markedly. Example: If you have a plant in an unheated garage over-wintering at head level, and one setting on the garage floor, which is warmer? The one at head level, even though there is SOME heat rising through the floor. Now, cover the plant on the floor with an over-turned cardboard box to trap extraneous heat rising through the floor. NOW, the plant under the box is warmer by 10-15*F than the plant on the head level shelf.

Al

newhostalady..your planters are so attractive!..they'll look great with plants!..Al gave you such detailed info!..I need to read it again to fully understand it all..nice elephant ears!..I figured those elephant ears are in a pot sitting in the planter temporarily right? (since your planters will have perennials)..hope your soil layers turn out well..

Thank you Al for explaining in depth and so clearly so that I can understand! I am sure that this is helpful to so many others. Here is what I understand:

So I will change the layers to 3, 3, 3 and 5 inches.

There will be no legs on the planter but the planter will rest on the concrete slabs in order to gain heat conduction through the bottom.

Mulch heavily for the winter. This will help to trap heat.

_________________________________

My plan is to also cover the planter with heavy plastic or glass (an old window). Wondering whether there needs to be a bit of air circulation within.

Is it important to screen the granite?

When planting, should I be trying my best to keep the layers intact?

Nicholsworth, it is great to have Al help out with my project. I am so thankful.

My elephant ears are in a pot in the planter. I have four other pots of the same. We were just running out of room so I figured I would just place one in there. We don't have the area where the planter will be placed ready yet. So the planter is just sitting on our deck. I will need to remove some plants, place the concrete slabs and then set the planter in that location. And then I will be preparing the layered media. I will also have to make sure I prepare the planter for winter. This is quite the project!

newhostalady..I never got a notification for your comment!..aren't elephant ears fun?..like super sized hostas..I hope the hardest work to finish your project is over..what's ahead will be the most fun part :-) I'm going out to "move stuff around" ..pots..plants..soil etc Lol..

Yes nicholsworth, they are so much fun. Each leaf getting bigger than the last.

I cut a print of my hand and placed it on the biggest elephant ear I have!

My husband added some wooden boards on the bottom to reinforce it. Those boards are running the opposite way from the bottom boards of the planter. The boards are quite spaced to allow for drainage. Insulation has been inserted on the sides.

We've decided to place the planter directly on the soil. Any space on the bottom will be covered up for the winter to allow for some bottom heat.

Yes, it's time to move stuff around. Sadly, I feel the end of summer coming soon.

newhostalady..WOW!..what a big leaf..mine are Jack's Giants..is yours a Mammoth?..or Thai Giant?..those are bigger than mine..a hand cut out is a clever way to show their size!..your husband builds nice planters..such good craftsmanship..I have the same feelings about summer ending :-( why is summer so short and winter so long?..

Nicholsworth, I am not sure which EE I have---can't find the tag. I don't believe it is a Jack's Giant---but it certainly does look similar. I'll let you know if I find it.

I've always thought that it would be perfect if we could eliminate two months of winter and add the two months to summer.

newhostalady..I would LOVE a shorter winter..but since we have no control let's get busy EVERY day and get the most out of summer and fall right? :-)

You are absolutely right!