annual [ AN-yoo-uhl ] noun: a plant that lives only one growing season
An annual plant completes its whole life cycle of germination, growth, flowering, setting seed, and dying, all in one year or growing season. Winter annuals are a variation of this type: they have seeds that germinate in late summer or fall, but do not flower until the following spring or summer, after which they die, returning their seeds to the earth, whence some of them will repeat the cycle. Some common weeds, like non-natives Cardamine hirsuta (hairy bittercress), Poa annua (annual bluegrass), and Stellaria media (chickweed), are winter annuals.
Left to right: Cardamine hirsuta basal rosette and flowers, Poa annua, Stellaria media.
The Mid-Atlantic Region is home to some familiar and lesser known native annuals that often persist in the landscape through self-seeding: Ambrosia artemisiifolia (common ragweed) whose pollen is a common allergen; Helianthus annuus (common sunflower), a nectar plant for myriad pollinators, larval host to the silvery checkerspot butterfly, and food for birds, livestock, and humans; Impatiens capensis (orange or spotted jewelweed), a larval host to various moth species; Nuttallanthus canadensis (blue toadflax), a host plant for the common buckeye butterfly; and Pseudognaphalium obtusifolium (sweet everlasting), a host plant for the American lady butterfly. The latter two may also be biennial.
Left to right: Ambrosia artemisiifolia, Helianthus annuus, Impatiens capensis with sweat bee, Nuttallanthus canadensis, Pseudognaphalium obtusifolium.
Many annuals in the Mid-Atlantic Region are non-native and can be perennial in warmer climates. Although indeterminate tomatoes are cultivated as an annual here, in their native habitat of Central and South America they are are perennial. Determinate tomatoes are annuals in all climates. Non-native annuals grown for their colorful foliage include Coleus and Caladium (elephant ears). Those that attract pollinators include easy to grow tropicals like: Calendula officinalis (marigolds), Gomphrena globosa (globe amaranth), and Zinnia as well as highly fragrant Mirabilis jalapa (four o’clock) which opens in the evening. Broadleaf evergreen shrub, Lantana camara (common lantana), is an annual north of USDA zone 7. Discover Five Things You Didn’t Know About . . . Annuals or that you may not have learned in this narrative.
Clockwise left to right: Caladium ‘Summer Pink,’ Lantana camara with duskywing skipper, Calendula officinalis with fritillary, Gomphrena globosa with monarch, Zinnia with eastern tiger swallowtails, Mirabilis jalapa.
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