Knitting is as relaxing as working in the garden, and you don't need nature's cooperation for results. You can purl rain or shine. I can purl as meditation. Needles are key. They must have a smooth, slippery surface so that you develop a mental rhythm undisrupted by snags. Even slight snags distract. Bamboo needles are great for the environment, but not for my meditation, because they tug ever so slightly at the yarn.
Old metal needles work fluidly -- and it's easy enough to find old ones. I also like highly polished reclaimed wood, vintage, or Laurel Hill, which makes the most wonderful slippery needles out of fallen branches of Forest Palm.
I discovered a convenient, lovely little spot that carries Laurel Hill needles. The place is called Knit Haven in New Haven, where Church Street and Whitney Avenue meet, near the Dunkin' Donuts. Their selection of yarns is well-chosen, mostly wool, mohair and alpaca with some skeins of silk and cotton in colors from cotton candy and charcoal gray to earthy, hand painted patterns from artisans in somewhere in upstate New York. What they don't have is reclaimed yarn. That's the stuff that veteran, brilliant spinners make out of old sweaters, newspapers, plastic bags, T-shirts. They can turn amazing things into continuous fiber that knitters convert into cable knit cardigans. Etsy.com carries a lot of these and they are beautiful.
I would love to knit a sweater out of fiber from recycled water bottles or reused plastic grocery bags. These fibers exist, but they seem to be restricted to wholesale buyers such as Patagonia. If anyone figures out how to spin a skein of recycled water bottles, let me know.