As every gardening situation is different, it helps to make suggestions or recommendations that are based on science rather than empirical observations that may be influenced by issues or variables about which we have no first hand knowledge. And the science is: 1) Organic matter does not raise soil pH, at least to any permanent degree (some OM, like certain animal manures, may be highly alkaline and provide a temporary bump until they are fully decomposed). OM tends to lower pH slightly, due to a) carbon dioxide from decomposing organic matter and root respiration dissolving in soil water to form a weak organic acid; and b) formation of strong organic and inorganic acids, such as nitric and sulfuric acid, from decaying organic matter. Once the decomposition process is pretty much complete, the resultant product is more or less neutral in pH. 2) Soils high in organic matter tend to resist changes in pH. This is because OM has a buffering capacity as a result of a high cation exchange capacity (CEC) that holds and binds elements - specifically hydrogen - that would ordinarily affect swings in pH. Thus, OM tends to be a stabilizing factor in soils rather a major activator in the adjusting of soil pH. 3) The addition of OM to a soil doesn't increase the range of plants that will grow in that soil except indirectly. And that's because of its physical properties that encourage the development of populations of beneficial soil organisms, its ability to improve soil texture and therefore its moisture holding capacities and its ability to bind and hold nutrients necessary for plant growth and health until they can be digested and made available by the soil organisms. But the bottom line is that unless the soil pH is in the range that most plants prefer (slightly acidic to neutral), simply adding large quantities of OM is not going to supercede or override a pH that is greatly skewed in one direction or another. Or at least not in any kind of rapid fashion. If the pH is not to the 'plant's liking', it is not to the plant's liking and simply adding OM is not going to make "plants grow quite well" irrespective of pH. If your soil is highly alkaline, adding recognized soil acidifiers is the only reliable way to make adjustments, which may very well be quite temporary and need to be repeated periodically. These would include elemental sulfur, peat moss, large quantities of not fully decomposed organic matter or ammonium based synthetic fertilizers. And of course, the last is not an option in an organic gardening context.

There is a chart at: How to Apply Sulfur to Increase Acidity that gives the amount in lbs/100 sq.ft. It would be .35lbs for 10 sq. ft. I would not apply it all at once. I would apply 1/4 now and 1/4 about every 3 months: (June, Sept., Dec., and when the ground thaws next spring.) The reason for this is that it takes a while for it to get down to the depth, so this would keep from getting too strong at the surface. Of course this needs to be applied under the mulch. Just rake the mulch back and then sprinkle it back in place. Here is a link that might be useful: How to grow rhododendrons and azaleas.

That really is their common name that almost all people use and also most information shows it as: Alaska cedar Sometimes called: Nootka False Cypress or Yellow-cypress and the best names: Nootka Cypress or Alaska Cypress. It's not correct calling it cedar like above because it's not really a cedar. It really is in the cypress family (Cupressaceae). It really should be called Alaska cypress, but very rarely does anybody call it that. Another example would be the Eastern Red Cedar (Juniperus virginiana) which is in the cypress family (Cupressaceae) and even though it is not a cedar and should not be called that, it is just the accepted common name by almost everybody. Quirkyquercus was not really wrong in a way because the ones that are wrong are the ones that started calling it a cedar many years ago.

Nikkos with morning sun and filtered afternoon sun should be more than enough. My mom's Nikkos get morning sun (7 to 12) and hardy any afternoon exposure, her Nikkos been blooming nicely all these yrs... I don't have good experience for my plants get from HD or Lowes..you often find badly wilted Hydrangeas in these centers. I think true Nikkos don't bloom on new woods, so if the Nikkos you got has exposed to some kind of freeze earlier this yr, you won't get a lot of blooms. My mom likes to force some of her Nikkos and Endless Summer with high phosphate fertilizers (Vigro - colorburst) when she see the buds and the ES really likes it...but one thing tho, if you want blue flowers, if you use a high phosphate colorburst type of fertilizer, you probably will need to treat the shrub once or twice with Aluminum Sulfate (as soon as you see the buds) - 1 tablespoon per gallon (no more than one application per two weeks, do it not on the same week of the fertilizer appliaction) - drench the plants (make sure the soil is moist before the drenching).. my expeience with BB is it being a better bloomer all season, they will get sun burn, less wilting tho..but my mom doen;t like the white blooms as much - oh well... the Cityline series of hydrangeas can tolerate a lot of sun, at least in New Jersey, almost full sun, except days over 90 and no clouds in the sky..and if you can find one that's loaded with buds, you wont be disappointed..the flowers are large, very bright red/pink blooms, and last pretty long on the plant...if you want blue flowers, get Venice, Vienna or Berlin..Paris is very deep red and hard to change color...I have seen violet-blue Venice, pale blue Vienna in some gardens but if you get one from the nursery, chances are you will get the red/pink ones... good luck.. jmho.