Wow! What a great site. I have two questions right off the bat:
Hydrangeas mine are about two feet tall and are an ugly pinky-mauve fronting my orange brick house; friend says I can change the color to green/white (which is what I prefer) by adding coffee grounds at soil level. Will this not, if anything, change blooms to blue because of the acid? Is there anything I can do to get rid of the mauvey pink and get the green/white blooms?

Hostas: Plants are around a year or two old, very long spires with very little flowering on some of them. Should these spires be removed or should I just leave them alone?

Thanking you in advance, and I promise to research the site to avoid redundancy.

Hostas, the spires are the flowers. Some people remove them, others let them bloom, some of the hostas have lovely flowers. After blooming, then cut down to the bottom of flower stem.
Hydreangea...if you have a pink one, then it depends on it changing colors. Some pink ones stay pink regardless. To make them lavander or purple, I put coffee grounds, apple peels and cores, and citrus fruit on the ground under the plant. Or you can buy a chemicle to do that. I use the above as it is free. A pink or blue hydrangea will not turn white or any other color, because that is not in their gene pool. If you hate the color, in fall, move it, and put something else there. Do a search on the net for white hydrangea. There is pee gee which is a bush/small tree. Then there is climbing tree hydrangeas. Oakleaf hydrangea, white, gets huge. If you want deep purple, then go to starbucks for used coffee grounds to put under your hydrangea. That pink may be clashing with the color of your brick house.
Darlene