Bob, The free arborist woodchips are what I use, it fits my pocketbook and does a good job. When I see trees being trimmed I stop and ask if they need a place to dump them, usually they do. Where I am now there is a kids camp, they have a lot of tree work done every year and I usually get it from them, dumped at my place. I have a lot of areas planted and I could not keep up with the weeds without it. If you get it from a arborist who has a good chipper it is pretty uniform in size and looks good. When I want something nicer I get some from a local saw mill, it is finer and breaks down faster, its the bark and wood that comes off when they cut to flatten the tree for slicing. They also have sawdust but I rarely if ever use that. Around here the electric company trims the trees along their line about every 2 years and they always need to have a place to dump them, they contract with a co. called Asplund, I have used their chips also. I understand the problem in dry climates, I have made a real rock garden, created a 15" layer of fast draining soil, 1/3 decomposed wood chips, 1/2 sand and 1/3 gravel-small. I grow as many small dry climate plants as will decide to accomadate me. Most purchased from Laport Ave. Nursery, Fort Collins, CO. In the rock garden I use a gravel mulch, I have a friend that has most of her garden mulched with the gravel. She is a nationally known rockgardener. So many things self sow very successfully in the gravel. I have not been able to do it that extensively due to budget, gravel is very expensive here, haven't found a way to get that free yet. Here we usually get up to 60" of rain a year, it's a temperate rain forrest according to the Nat. Weather Serv. Everything grows with abandon except the one plant I have had a problem with. On Sun, Mar 26, 2017 at 6:47 PM, penstemon <penstemon@q.com> wrote: > > >When using arborist's wood chips (not retail bark chips) in the garden, > the > >chips do not bind up nitrogen in the soil if you just lay them on top of > the > >soil. Here the arborist's chips are free but you do have to take a truck > >load, about 10-13 cu.ft. if you are spreading them yourself. > > In a semiarid climate like mine, wood mulches, like mulches of other > organic matter, prevent rainfall from reaching the soil. > I use gravel, or no mulch at all. > Bob Nold > Denver, Colorado, USA > _______________________________________________ > pbs mailing list > pbs@lists.ibiblio.org > http://pacificbulbsociety.org/list.php > http://pacificbulbsociety.org/pbswiki/ >