Are pine needles a good form of mulch
Multnomah County Oregon
They can be, especially for acid-loving plants like blueberries. A key item would be to make sure they are fluffed up so you get the benefit of air for insulation as well as making sure water can drip through.
Can I amend my soil using evergreen needles and what else should I use? Also I just moved here to find my 3 raised bed filled with the ground soil i.e. clay how can I cheaply amend the soil? Thank you Penney
I would not 'amend' the soil with pine needles. Anything you want to use (leaves, needles, manure) should be fully composted to amend the soil. The 'cheapest' method is not the speediest. If you are primarily interested in preparing the soil for planting next spring, then using cover crops are a cheap and easy method. If it's really packed clay, then using something like oilseed radish is good because you can plant it now, it will grow until a hard frost and the roots will decompose adding organic matter and 'channels' for air and water. Other good cover crops are legumes (crimson clover, Austrian field peas, hairy vetch, fava beans) because they can all fix nitrogen in the soil. To retain the benefit, you need to cut the plants at the soil level and leave the roots (that is where the N-fixing bacterial nodules exist.) If you pull the roots, you are losing much of the benefit.
Here are several resources for vegetable gardening which includes soil improvements:
"Growing Your Own" https://catalog.extension.oregonstate.edu/em9027
"Raised Bed Maintenance" https://catalog.extension.oregonstate.edu/fs270