From what I can read, it says the size is a inch or less. You want anything 1/2" down for 511, some prefer 3/8 ". The product you showed is likely to be to large, unless you break it up. My lowes has ine bark mulch, nuggets, fines, check out your local lowes! My home depot didnt have anything! Good luck!

Indeed, whether you are making 5-1-1 or the mix that Ray uses in his self-watering containers, you'll want bark that is 1/2 inch or less, with the majority of the fines in the 1/8 to 1/4 inch range.

Josh

The Hapi-Gro mulch has been discussed on this forum in the past. In one thread that I'll link to there were photos of what was in the bag that showed it is quite variable. But I think most of the experienced users of 5-1-1 thought it was a decent choice in either form.

Here is a link that might be useful: Another discussion of pine bark fines

This post was edited by Ohiofem on Sat, Feb 15, 14 at 13:08

Why exactly does the bark have to be small chunk fines instead of shreds and larger sizes as in your everyday mulch? Not arguing for that, but just curious.

The large chunks are problematic for several reasons: first, the large size reduces overall room for roots to grow; second, the giant bark makes for drainage that is too fast and dry in the top of the pot; and third, small particulate lodges between the large chunks in the bottom of the pot and actually impedes drainage.

Shredded bark, on the other hand, tends to compact and make a fibrous sort of mat, which holds an excessive amount of moisture.

Josh