There is one issue, there are 2 large evergreen Western hemlock trees that live there now that will be coming down soon. The ground under those trees is dry and of course covered with needles so nothing grows there now.

We are having the stumps removed too, but I think with raised beds I can deal with any old roots in the ground. What I wonder about is the acidic soil and any other chemical changes that those big trees might cause that prevent even weeds from growing there. I assume it is mostly due to lack of water with the big tree there, just wondering if there is something else?

Would you recommend I rake away all the tree materials and lime the area this fall or ??

I also want to create a berry patch - blueberries, raspberries and strawberries at least in the general area of my small garden. Blue berries like acidic soil, but any other concerns with them?

I am in King county - so thought to do the basic preparations as soon as the trees are gone - before it gets wet.

It is also a bit of myth that the fallen needles make the soil more acidic. That too is incorrect. There is some leaching from fresh needles but not enough to make a significant impact on pH and what impact there is is limited to only the soil surface. Conifer needles lose any acidity they may have with age and as they decompose.

As mentioned above, clear the area of the conifers and it will rapidly regrow with probably something you don't want. If you construct and fill the raised beds this fall, I'd plant with a cover crop for the winter. If leaving until next season, I'd make sure I mulched the area thickly and thoroughly.

Come to think, you could certainly plant the cover crop in the cleared ground as well. But it may not be as effective in keeping down the unwanted growth as would a standard mulch.