i just started using granular sulphur for this purpose. my property is on top of a columbia river mega flood bank, my soil is not acidic in the least bit. takes a while to take effect from what i have read, but its decently cheap and does not need constant reapplication like other methods (cottonseed meal etc)

eeldip, can granular sulphur be purchased at most garden stores and how much do you use? Do you use any bark mulch or other kinds of mulch? Im wondering if the chicken manure I applied at one point, made it more alkaline? Thank you so much!

granulated sulphur is pretty hard to find. its not that heavy so mailorder would make sense if no one around you carries it. i got mine from Concentrates Inc, a great farm/garden store here in portland (well, they recently moved to milwaukie).

i follow the directions for application. you don't need much at all, and it lasts a long time.

i also do use bark mulch around my blueberries/huckleberries. mostly for aesthetics. its not a long term solution.

also, definitely buy a device to test your soil acidity so you know when enough is enough. they are not expensive.

link to sulphur below.

Here is a link that might be useful: follow the directions on the box!

Are your rhodies near concrete? that can make soil alkaline, enough to bother rhodies.

any kind of conifer mulch should help lower the pH. I mulch mine with whatever blows down out of the trees over the winter. Bark mulch won't make your soil alkaline and doubtful the store bought compost would either. You don't lime your soil do you, or add any kind of calcium fertilizer?

Steer manure can make soil more alkaline.

Not all soil in the same general area will be the same; here in western WA most soil is very acidic but I have yet to have a garden that didn't have near perfect pH for whatever reason. Soils that didn't form under coniferous forest or in a wetland will not be as acidic, so if you're on a floodplain or on glacial till you won't necessarily have acidic soil.

Maybe dig the dirt out and give the shrubs a new area of acidic soil to grow in. Or move them to another spot, that is not alkaline, unless your whole place has the same condition.

Down here there are some areas near salt water where the soil contains sea shells or is derived from old sea beds and is now limestone based. Maybe you have this kind of situation there.

I don't think manure is recommended for rhodies. Too darn hot for their delicate roots.

Ground bark makes a great mulch. If your plantings are large enough you can use prunings from your other shrubs and remove the branches after the needles or leaves have fallen off. That is what nature would do.

If you are wealthy leaf mulch would probably do a good job.

I have used cocoa hull and rice hull (not at the same time) will no ill effect. I thought the light color of the rice hulls would help to keep the soil over the roots cooler in summer. Don't know if it helped, but it didn't hurt.

Dried grass clippings.

Recycled potting soil.