If you are filling a raised bed several mixtures of sand to compost should be considered based on the type of plants you wish to install.
50-50: Herbs, Ornamental plants.
75-25: Vegetables, Fruits.
90-10: Heavy feeders (Cabbage family, Root crops.)
Pseudofumaria lutea (syn. Corydalis lutea) - Yellow Fumewort
Yellow Fumewort is one of those perennials on par in structure with Astilbe, Bleeding Heart and some of the Ferns. While it's foliage is a interesting greenish-gray yet it's stems can be tinged with red generally it forms a fine textured mound of foliage. The Interesting part about this particular Fumewort is it's flowers which as the name suggests are bright yellow and borne in racemes. For note a raceme is a type of flower cluster that is indeterminate, unbranching and bears flowers with very short stems that come off a central stalk. At the rear of the flower where it attaches to the stem the flower takes on a bright green coloration that adds to the visibility of the overall flower stalk. It should be noted that Yellow Fumewort is a short-lived perennial that heavily self-seeds. The name Fumewort is derived from the aroma the foliage releases when handled and imparts on your hands and equipment with contact. The odor somewhat resembles the glue you use with airplane models. Dormant seed can travel quite a distance too which can be a pleasant surprise when paired with heavy volunteer plantings of Lupine which takes similar conditions. Generally Yellow Fumewort prefers partial shade decent soil that drains well and seems to do better in cooler weather. Fumewort unfortunately is not native to this continent, as it originates in the region of Switzerland but it has made itself at home and thankfully unlike wisteria is well-behaved.
Lupinus perennis - Wild Lupine
Lupines in general are rather attractive garden perennials, though their cultivation is somewhat difficult as they do require particular care varying on the individual species. One native species to North Carolina is the Wild Lupine, which can be acquired as seen in those 'Wildflowers of the Blue Ridge' postcard/seed packet seed collection packs. I was first acquainted with the patience required for lupines with the actions of a neighbor back in New Jersey, she planted from see3d a group of lupines which were of a cultivated variety. These lupines sat and produced only sparse foliage for a year or two. Admittedly the fine radial foliage full of fine leaflets was attractive exotic and resembled nothing else on the entire block. When the little Lupines finally bloomed what a bloom, I don't know if it was the Russel hybrids or the tutti frutti mix but the colors were cheery and were like fireworks streamers flying skyward in garden form. Wild Lupine is quite a show if you get a chance to pass through the back roads of Fort Bragg towards Candor in late spring/early summer. The clusters of blue break up the rich green of the pines effectively and can be seen quite well even at forty miles an hour. The biological advantage to planting lupines is simple, they provide ample nectar to bees and butterflies at a great time of the year. It is worthwhile to mention Lupines are of the Pea family and are likely to fix nitrogen in the soil, improving soil quality over time. The issue with Lupines is they simply do not transplant well which in turn suggests that it might be wiser to start from seed and be patient. As far as culture goes lupines just need average soil with good drainage and a fighting chance.