I'm a little confused about what i should use to help build up my soil for certain plants. I'll be using composted manure for things like lilacs, mock orange and clematis, but what about acid-loving plants like rhododendrons and (i think) magnolia? I've got some rotting cedar stumps around, could i maybe mix some cedar in with manure to make it acidic, or is that crazy? Does anyone know of a good book that explains different soil compositions and which plants like what from an organic perspective?

The PH for Magnolia is 6.0-7.0 and Rhododendren is 4.5-6.0 I would use your composted manure.

I use composted manure for everything, with the possible exception of succulents around my walkways that live in the sand, & even THEY were originally planted in soil amended with compost. You might try covering any topdressed composted manure with a layer of pine needle mulch around your rhodos to add to the acidicity. Honestly, I pay very little attention to pH levels & I have very diversely planted borders. I think the organic gardening techniques of topdressing with compost & overlaying the soil with mulches attracts so many earthworms, & that the EARTHWORMS change the nutrients in the soil into forms so easily taken up by plants, that pH isn't the worry for us, as it might be for those using chemical fertilizers & persticides. Can anyone back me up here? My observation is from my own experiences over the years.

You speak Truth. In a polycultural garden, the soil becomes self-regulating. Only a few plants do better or need highly acidified soil, Blueberries, Rhodos, etc. A handful or two of dried pine needles right around them will help.

At one point I ran around with a pH meter, sample here, readout there....humbug! Soil is best at neutral pH and an enriched soil (compost) maintains a neutral Potential Hydrogen (the ability of roots to take up nutrients)

Earthworms live in a balanced soil. It's a chain-reaction. And it's far less complicated than simple common sense!

John / Ecologicals

Great advice everyone! Just building healthy soil will solve most of your gardening problems. One little thing I've done in the past with good results for acid loving plants is I work my used coffee grounds into the soil around the acid loving plants I'm growing. Also have given them a dose of cold coffee too. They seem to thrive and it's an easy quick boost. Of course the side effects are lupines that are all strung out on caffeine...but hey - better them than me!!!
Happy gardening!
Janet

Thanks, all. Well that's an easy answer, so i like it!
-johannes

Organic gardening truly is simpler than chemical-dependent gardening. truly.