Swamp milkweed (Asclepiasincarnata) grows 4 feet tall in full sun in normal to medium-moist soils and thrives in rain gardens. Image by Uli Lorimer/CC BY-NC-SA 2.0
New England aster (Symphyotrichumnovae-angliae) blooms in late summer and grows 5 feet tall in wet to slightly dry soils in full sun, although it will tolerate some shade. Image by Tom Potterfield/CC BY-NC-SA 2.0
Wild bergamot (Monardafistulosa) blooms midsummer and grows 4 – 5 feet tall in sun or part shade in dry or moist soils. Image by D.J. Sattler/CC BY-NC 4.0
Foxglove beardtongue (Penstemondigitalis) is an early bloomer that grows 3 feet tall in wet-dry soils in full sun. Image by DaveCZ2/CC BY-NC 4.0
Gray-headed coneflower (Ratibidapinnata) grows 4 – 5 feet tall in clay, marginal and normal soils with medium moisture in full sun.
Black-eyed Susan (Rudbeckiahirta) grows 2 – 3 feet tall in wet or dry soils in full sun. Image by Kevin E. Metcalf/CC BY-NC 4.0
Stiff goldenrod (Solidagorigida) is a fall bloomer that grows 3 – 5 feet tall in well-drained soils in full sun. Image by Aaron Carlson/CC BY-SA 2.0
Little bluestem (Schizachyriumscoparium) grows in compact 2- to 3-foot-tall clusters in dry to wet-dry soils in full sun. Blue summer hues turn pinkish or orangy in fall. Image by Susan Bury/CC BY-NC 4.0
Table for 200
The word is spreading: Monarchs need milkweeds. They’re the only plants their caterpillars will eat. It makes sense, then, that people concerned with the drop in monarchs in the U.S. are adding milkweeds to parks and backyard gardens. The plants’ stems and leaves provide an irreplaceable diet for caterpillars, and the flowers feed adult butterflies and bees. But as many gardeners will attest, those aren’t the only guests showing up for dinner.
Expecting to find only hungry caterpillars, many gardeners are alarmed when they see their milkweeds covered with tiny orange bugs: oleander aphids. Just like monarch caterpillars, these insects feed on the plants’ sap. They may be unsightly, but they’re typically harmless.
Still, many frenzied gardeners look for ways to rid their plants of aphids, from applying isopropyl alcohol, soaps, detergents and insecticides to bringing out the vacuum. But even the most benign methods — gently brushing the aphids off by hand or spraying them with clean water to wash them away — can harm monarch eggs and caterpillars, the reasons people planted the milkweeds in the first place.
Fortunately, ladybird beetles, lacewings and other native insects love to eat aphids. Lacewing larvae in particular are known as “aphid lions.” To keep plenty on hand, gardeners often plant asters and sunflowers — favorite foods for adult lacewings — among their milkweeds. Image by Brian Henderson/CC BY-NC 2.0