Elderberry stems have soft pith that stem-nesting native bees can excavate; the Lady Bird Johnson Wildflower Center flags the species as providing nesting materials and structure for native bees.
Standing clumps and stems provide nesting materials and overwintering structure for native bees.
NC State documents stem-nesting bee use of dead Liatris stems through winter. Cut back to 12-24 inches in late fall and leave standing through the cold season.
Dill's hollow, pithy stems are the kind of standing structure stem-nesting native bees use when left over winter; this is the general habit of hollow-stemmed herbs rather than a dill-specific record in the cited sources.
NC State Extension notes native bees nest in the dead, hollow stems of roses; leaving some cut canes standing provides nesting habitat.
Dense clumps and standing stems through winter provide overwintering habitat for ground-nesting native bees.
Native bees nest in the dead, hollow stems through winter; the load-bearing reason NC State Extension advises cutting back stems to 12-24 inches in late fall rather than clearing flush to the ground.
The Lady Bird Johnson Wildflower Center lists Yucca glauca as providing nesting materials and structure for native bees, and food and nesting for small mammals, birds, and reptiles.
The Lady Bird Johnson Wildflower Center documents the species as providing nesting materials/structure for native bees; NC State Extension likewise notes native bees use this plant for nesting materials.
NC State explicitly notes "Dead stems are used by stem-nesting bees" and recommends cutting back to 12-24 inches in late fall to let the standing stems shelter overwintering bees.