The north and east sides of my garden have pine trees surrounding them I have 6 hours sun and I can grow all vegetables except Tomatoes with very long DTM watermelon with long DTM. I have my plants in raised beds so the roots of the trees are not a big issue. If you have an in ground garden you will need to watch out for pine tree roots sucking away all the moisture. The main issue here seems to be the sun. I would guess you could grow all leaf vegetables peas and maybe bean successfully.

For the record, as your message states, these are Doug Fir trees not pines. The southeastern posters have never seen a doug fir before I'm sure. Not every conifer is a pine. Pines are rare around here actually. As one of my natural history books says, if you're in western WA or OR, and you're looking at a tree, 90% probability it's a doug fir. Pseudotsuga menziesii. Not Pinus. It does make a difference in how you garden under them. The issues are, shade and root competition. Yes the soil and leaf litter under a doug fir will be acidic, but the soil is anyway. pH below 5 is not uncommon here. Hardly anything grows under doug firs and red cedars (Thuja plicata) because their roots take all the water, and their canopies shade out all the sun. You're supposed to plant your tree climbing roses towards the edge of their branches and let them scramble up the branches, not the trunk. I once planted a Paul's Himalayan Musk under a small and scraggly doug fir, on the sunny side, and tried to keep it watered. It struggled for years until I moved and now it's probably dead without me there to haul water to it. It did grow, and bloom, some, but it kept reaching away from the tree. What does grow under doug firs? Take a hike and see. Sword fern, deer fern, lady fern; red and evergreen huckleberries; snowberry; blackberries; red flowering currants; salal and creeping mahonia; rhododendrons and azaleas; vine maples; wild ginger; trillium, fairy lanterns, false solomon's seals. Oh, and the native roses: R. gymnocarpa mainly as it likes shade, and some R. nootkana and R. pisocarpa, but they need more sun. My little greenbelt of 40 yr old doug firs is filled with salal, hazelnut, huckleberries, blackberries, indian plum, cascara, snowberry, serviceberry, cotoneaster, rosa gymnocarpa, mountain ash, big leaf maple, and english holly. It's pretty dense. The birds love it. I stuck a couple rhodies on the edge, and a rosa nootkana but they're struggling from too much root competition. And in any case hardly anything chooses to grow directly under a doug fir, near the trunk, except ferns. And nothing needs a specific pH, or nothing would grow anywhere.

My sweet little three year old deer fern are dying under the cedar. I have been told that shade isn't the only problem with cedar. Seems cedar itself is toxic to certain plants. Is that a significant issue? What grows like crazy under mine is wild ginger which planted itself, bleeding heart, and self planted sword ferns. I did not want the sword ferns because they are not evergreen so I purchased some autumn ferns and the deer ferns. I have some struggling rhodes on one end of the bench that gets more sun. They did well for several years, but I do not fully understand their struggles which seemed to have started two years ago when their leaves were nearly destroyed by what I think may have been some type of beetle. Last year the leaves were not touched, and the plants seemed to recover though the flowers were sparse and small. I feed them but maybe not often enough. They are small rhodes and were beautiful in their place until they sharply declined. There is a "tail" area on the shadiest bench that gets lots of sun but every plant I have put there has died. It is almost as if there is something toxic in that soil. I am about to put landscape cloth and river rocks there and call it good enough. Any suggestions for me? I want to purchase a new rhode, but am somewhat reluctant until I grow to understand what happened to the existing plants.

lilies and stonecrop do pretty well in acidic soil. lily of the valley thrives under my pine. if you tell her to mix in some organic mix, that should take some of the edge out of the soil. some hostas should be able to survive too. we have a bleeding heart on the edge of our pine's radius - it does very well.