Christina Pax
Frederick County Master Gardener Program

Perennial sunflowers (Helianthus spp.), like their annual sunflower cousins, have a cheerful yellow bloom. They are typically smaller both in flower and stature, although some are still quite tall. They generally begin blooming in late August-September, then continue well into October and sometimes even November.

Finches and chickadees love the seeds of perennial sunflowers. As a group, they prefer good, full sun; a moist, sandy soil; and will usually require some room, as they can become tall. They typically have both opposite leaves (on the lower part of the stem) and alternate leaves (just below the flower clusters).

Helianthus decapetalus, Thin-leaved sunflower, or Ten-petaled sunflower, blooms from July through October. It likes full or part sun, prefers a sandy soil, and grows from two to five feet tall, depending on the circumstances. Helianthus divaricatus, or Woodland sunflower, is a good sunflower candidate for less sunny locations, as its name implies. It also prefers less moisture than the other sunflowers, preferring dry to moist soil. Both of these are native to Maryland.

Helianthus angustifolius, Swamp sunflower, has a pointy-petaled, yellow, daisy-like bloom with a dark center. This Maryland native blooms late August through October. Swamp sunflower prefers a moist, sandy soil of average fertility.

Butterflies will visit these flowers, and if you let them go to seed, birds will devour the seed heads. Once established, a single clump can take command of six to nine square feet of space in your garden, so plan accordingly! Swamp sunflower typically grows 5-7 feet tall, and is somewhat vulnerable to slumping over during a heavy rain, but if you cut it back in midsummer you should be able to keep it more compact and eliminate any need for staking. Another flower to consider would be Helen's flower…

Helen's flower, Helenium autumnale, is in the sunflower family. Also (much less glamorously) referred to as "Common sneezeweed," it has anything-but-common wedge-shaped petals that are broadest at the tip. To add to the curiosity, each petal has three teeth at the tip, making it one of the most interesting textures found in a yellow, daisy-like flower.

Helen's flower is a Maryland native that blooms July through November, when it has reached a height of three to five feet. This one also likes a damp spot in the garden, and is an excellent candidate for a rain garden. It will tolerate drier soils, but will be shorter and more delicate.

Hummingbirds like red flowers. For the deepest velvety-red color you can imagine, there is Lobelia cardinalis, Cardinal flower. Although Cardinal flower starts blooming already in July, its habit of opening up the flowers along its long stalk just a few at a time, from bottom to top, extends its bloom season long into October. This seems to suit the hummingbirds just fine…they will sometimes stake out a patch of cardinal flower and even fight over it because it provides nectar for such a long period of time.

Part sun is better than full sun for Lobelias, as both leaves and blooms will fade in full sun, and I have even seen the leaves burn where the sun exposure was very strong. In the wild, you might see this flower in small, damp clearings where a little patch of sun falls to the forest floor, often absolutely covered with swallowtail butterflies.

Although not as adaptable with sun requirements, Cardinal lobelia will forgive a departure from its natural, very moist soil preferences, adapting fairly well to dry locations once established. Since it is a short-lived perennial, many gardeners mulch lightly if at all around Cardinal flower, to encourage its seeds to sprout and also to avoid covering the overwintering crowns, which need to see sunlight through the winter months.

Cardinal flower's close relative, Great Blue Lobelia, Lobelia siphilitica, also blooms well into the fall season and is also popular with hummingbirds. Great blue lobelia is native to Maryland's piedmont and mountain regions. It starts to bloom a little later than Cardinal lobelia, usually in August. Both Cardinal and Great blue lobelia grow two to five feet tall, but often when they are grown together in a garden setting the Cardinal flower will be taller.

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