Quick answer: 12 native Maryland plants have a recorded bloom range that includes October.
12 species
- Black-eyed Susan Rudbeckia hirta · 42 states
- Blue mistflower Conoclinium coelestinum · 26 states
- Cardinal flower Lobelia cardinalis · 37 states
- Great blue lobelia Lobelia siphilitica · 32 states
- Maypop passionflower Passiflora incarnata · 13 states
- New England aster Symphyotrichum novae-angliae · 18 states
- Scarlet beebalm Monarda didyma · 18 states
- Spotted beebalm Monarda punctata · 14 states
- Swamp milkweed Asclepias incarnata · 25 states
- Swamp sunflower Helianthus angustifolius · 15 states
- White snakeroot Ageratina altissima · 7 states
- Witch-hazel Hamamelis virginiana · 28 states