That's fine - same stuff I use. You're mainly adding the peat to bring up the water retention in your bark/perlite to whatever level you want. Keep in mind though, that increasing water retention by increasing the amount of perched water the soil holds will end up being counter-productive from the plant's perspective. That's why I try to limit the sum of all fine particulates to somewhere around 1/6 of the mix or less.

Al

When measuring for the sphagnum for the 5:1:1, I'm assuming we are talking about a dry volume? i.e. If I buy a small brick of peat moss, I'd break it up into a dry powder and measure it like that. It seems that there would be too much of it if measured wet.

Yes - break up the clumps. I push mine through a 1/2 or 3/8" screen to do that, but you can do it with your hands.

Al

Well.......when I went to Lowes, they didn't have what their web site said they had. What they do have is a pine bark mulch by Gardenscapes. I went to the Gardenscapes web site when I got home, and the manufacturer states that it's 100% Southern Pine bark. I'm assuming this is usable for the 5:1:1 mix.

Yes, it's useable...and probably a little more durable to boot!
As long as the particle size is appropriate, it should serve you well.

Josh

Agree - what Josh said - sounds great.

Al

Thanks Josh and Al. Actually I should have put my previous post in my "How much fertilizer and/or lime initally?" thread, but I think you knew what I meant anyway. I'm still on my quest for the best product locally for the "5" in the 5:1:1. There are a couple of good possibilities at Home Depot also. I'll probably go there on Mon. or Tues. They have one product on their website that's 100% Southern Pine bark fines, and another 100% pine bark product that's

Use your mind's eye to picture what happens when you mix sand into a jar filled with marbles. You can fill a jar with a quart of marbles, but still pour a pint of sand into the jar - so did you ACTUALLY fit 1-1/2 quarts of material in a 1-quart jar? If you envision this arrangement, sand and marbles, what do you think the drainage characteristics would be? There's a quart of marbles but only a pint of sand, yet the drainage characteristics AND height of the PWT will be exactly that of pure sand. The only thing that changed by mixing them together is the o/a volume of water the mixture CAN hold.

The same can happen with the bark/peat/perlite mix. If you start having to add significant fractions of fine material (over about 1/6 of the whole) to increase water retention, you end up reducing drainage AND increasing perched water. This is precisely why adding a little bark and perlite to peat or bagged soils won't work as well as starting with a favorable size bark when building soils, and why adding a lot of peat to large bark doesn't work well either.

I think this is probably the clearest example (I've offered) as to why particle size is so important to how container soils function.

Al

OK, thanks for the correction. Don't know what I was thinking, except that I was thinking late at night, which is dangerous. I've read your Container Soils-... several times and should have known better. So it's still "mud" season up here, and a good time to do a little leg work to fing the right pine bark size for the job. To be continued.....thanks.

Hi Al,
Did I read in a post awhile ago that you could leave out the peat completely if you used partially composted bark with fines? That would be a 6 parts bark to 1 part perlite? Is there any downside to this?
BTW I'm the 'gritty mix failure
gal'...still trying to source bigger grit and smaller bark...almost there I think.
Thanks!
Julie

Hi, Julie. I remember you. ;o) When you make a soil, keep the thought in mind that you're trying to build aeration and longevity into the soil. You want it well-aerated, and for it to stay that way as long as you have plants in it. That's the reason for starting with a large fraction of bark instead of peat. The peat fraction is only there to adjust the water retention - nothing more. If your bark has a lot of large particles and few fines, you might need a little more peat than a 5:1:1 ratio. Maybe 5:1.5:1 will work a little better. If the bark is very fine, you may only need a 5:.5:1 ratio of bark:peat:perlite, or possibly no peat at all. as in the case of using Fafard aged pine bark. When using that, you can probably use 5 parts of bark, no peat, and maybe 2 parts of perlite to actually REDUCE water retention, because it's quite fine - finer than I like, actually.

Being new, you don't yet have a good feel for how to wing it and use your judgment as to how well a soil will retain water or drain. You could try this: Make a very small batch (less than a quart) of 5:1:1 mix. Fill up a 12 oz plastic cup (with a hole in the bottom) with the soil and completely saturate it. Make sure it's TOTALLY saturated - then let it drain. Hold the cup at eye level over a pan or collection saucer, then move the cup downward quickly over the pan/saucer. Just before the cup hits the saucer, reverse it's direction and lift it smartly upward. The water still in the soil will exhibit a tendency to continue moving downward (inertia of motion) when you raise the cup, and will flow out of the drain hole. Continue doing this until no more water drips out the hole. If you get more than about 3-4 tablespoons of additional water to drain from the soil, you probably have too much peat and not enough perlite.

Hopefully, you have a good handle now on how water behaves in container soils, so by next year you'll be familiar enough with your soil that you can tell by feel & by just looking, what's required. I know that all I need to do is look at a handful of the bark I'm using after I empty the bag, and I know just how much peat & perlite to add, and I learned it just from how my plants did the first year in the 5:1:1 mix. There IS something of a learning curve, but you'll be fine, and we're always here to help if you get stuck. ;-)

Al

Thanks so much Al. When I get all my supply ducks in a row I will try the experiment. I cannot believe how much info/help there is on this forum. I'm so glad that I found it! You ain't just a kiddin' about the learning curve however :)
Julie

Don't worry - it will all 'click' - it's not as daunting as it might seem. ;-) I admire people who don't just throw it all together and hope it works. Knowledge gives you wings to try and do things that wouldn't have been possible if you weren't doing something to separate yourself from the pack. Lol - there's nothing wrong with being a member of the pack, but think of the view ..... is it better if you're lead dog or running with the pack, looking at the lead dog's behind? You're certainly not going to hurt yourself by acquiring knowledge and putting yourself at the front of the pack!

You're doing GREAT, btw! Ambition and determination are wonderful assets. The old maxim 'you get what you pay for' is pretty true. You're paying your dues now, but it will pay dividends down the road for as long as you choose to garden in containers; so good for you .... and for everyone else trying to advance their skill set!!

Al

I'll second that. :-) (what Al said. ;-) )
JoJo

I'll third that what Al said! :-)

Fantastic information here and such kindness!

Mike

"There is no effect more disproportionate to its cause than the happiness bestowed by a small compliment." ~Robert Brault

Al