Handful of redwood tree needles I collected in front of my house 

and placed on a green metal bistro table on my deck. Note the
caked-on yellowish redwood tree pollen on the table.

I like using redwood tree needles in making compost, but when you have literally hundreds of thousands, maybe even miilions of them here in Guerneville alone, available to all of us who live here, we cannot compost them all even if we wanted to. They can drop off the trees year round since redwood trees are evergreen and not deciduous. There is a very brief period of time in the spring, I believe, when they seem to be absent or we have caught up with the immense amount of debris that has fallen during the winter, but as the summer drags on, you can literally see them collecting in the boughs of the redwoods and you know we are going to eventually have a brown snowfall. Yep, that is what I call it - brown snow. The first heavy Fall rainstorm and gusty winds will bring down zillions of them. River Road, here in Guerneville, is covered, roofs are covered, and you can barely see your steps or deck. This process continues throughout the fall and winter until the trees are almost cleared. During the heavy brown snow season I have literaly swept up so many of the leaves from my roof, gutters, decks, steps, etc. and all around my house, that I usually fill at least four, 32 gallon plastic trash cans. When I first moved into my house and had no compost pile, all of these needles went to the dump.

Now, I regard the needles as garden manna from heaven. Also, as noted in an article (Garden Doctors, by Lozano and Kilchherr, February 16, 2013) in the Press Democrat out of Santa Rosa, CA, redwood needles can be used around very acid-loving blueberries and presumably, other acid-loving plants. But I do not worry too much about the acid issue. Most plants love a slightly acidic soil to grow if there is a full complement of compost and nutrients that keep the acidity within a decent level. Also, when you compost the needles like I do, and compensate for their innate acidity by adding in various types of manures and using "green" manures from scraps and leftover food in my kitchen that is going bad, the acidity is lessened, in my opinion. By the way, I agree with the mantra of one of my fellow gardeners which is if a human being can eat it, it is okay to put in the compost pile. I compost everything I can get my hands on that comes from my kitchen. (Here's a little secret: I even put water into an empty salsa jar, for example, put the top on and swish it around to get the bits left in the jar. Then the liquid is poured into a kitchen waste collector and that is later taken to be composted when it is full.)

Now, the brown snow decomposes vey slowly if you just spread it around on the ground as a mulch, so it is best to compost it (http://www.hort.net/lists/medit-plants/dec99/msg00249.html). This is the first year that I am not do any composting in a pile with my redwood needles. I am doing sheet composting or layered composting. That is, I am spreading the needles in a layer, then adding on top of that, animal manures, sifted garden soil (to get the rocks out), composted kitchen waste (that I do separately in large trash cans with air holes), organic fertilizer such as blood meal to speed up the process, and compost I purchase by the cubic yard from out landfill operation. As I collect additional needles (almost on a daily basis), I put them down in a new layer and continue adding layers of the other items. I want to do everything I can to not disturb the soil by doing too much tilling or digging.