Brutal heat, tropical humidity, torrential downpours, or extended dry spells—welcome to late summer in the Mid-Atlantic region! We have plenty of excuses for our gardens looking tired and tattered now, but it doesn’t have to be that way. Building combinations around tough, adaptable plants means that our gardens can tolerate whatever the weather throws at us and still look good going into the later part of the growing season.
If bright and bold are your favorite garden themes, a vibrant purple-and-yellow combo is a wonderful way to go. Ironweeds (Vernonia spp. and cvs., Zones 4–10) are one of the best perennials I know for pure purpleness, and they are at their best this time of year. New York ironweed (Vernonia noveboracensis, Zones 5–9), in the 4- to 6-foot-tall range, pairs beautifully with a variety of late-summer yellows of a similar height. Try it with smooth oxeye (Heliopsis helianthoides, Zones 3–9) or cut-leaved coneflower (Rudbeckia laciniata, Zones 3–9)—two other Mid-Atlantic natives—for a pairing that’s beautiful to look at, a boon for late-summer pollinators, and a source of seeds for birds in fall.
New York ironweed’s rich purple flowers also look terrific with the clear yellow blooms of ‘Lemon Queen’ perennial sunflower (Helianthus ‘Lemon Queen,’ Zones 4–9), the quilled-petaled daisies of ‘Henry Eilers’ sweet coneflower (Rudbeckia subtomentosa ‘Henry Eilers’, Zones 4–7), the acid-yellow umbels of golden valerian (Patrinia scabiosifolia, Zones 5–8), and the golden yellow sprays of ‘Fireworks’ rough goldenrod (Solidago rugosa ‘Fireworks’, Zones 5–9).
If you prefer to keep your color combos on the softer side, how about some pink and white pairings? Late summer is prime time for Joe Pye weeds (Eutrochium spp. and cvs., Zones 4–9), and their tall stems make them a perfect match for the bobbing white “catkins” of white Japanese burnet (Sanguisorba tenuifolia var. alba, Zones 5–8). Another terrific late-summer combination is pink and white ‘Black Beauty’ lily (Lilium ‘Black Beauty’, Zones 3–8) against giant fleeceflower (Persicaria polymorpha, Zones 4–9), which tends to have a pinkish touch to its white plumes as its flowering season winds down.
Plant partnerships that have a tropical vibe are also right at home in our sultry Mid-Atlantic summers. Cannas (Canna spp. and cvs., Zones 3–11) are one of my favorite keystones for August and September combinations, as they contribute such bold forms and dramatic colors in both flowers and foliage. ‘Australia’ canna (Canna × generalis ‘Australia’, Zones 8–11), with practically black leaves and brilliant red blooms, is one of the best cultivars in my opinion, but my top pick has to be Tropicanna® canna (Canna indica ‘Phasion’, Zones 7–11). Its younger leaves are usually a rich mix of coral and orange hues; as they age, they tend to be more peachy-orange between the green striping.
Even before its bright orange flowers appear, Tropicanna® makes a beautiful backdrop for lighter-leaved partners, such as bright yellow ‘Golden Delicious’ pineapple sage (Salvia elegans ‘Golden Delicious’, Zones 8–11) or Giant Exhibition™ Limelight coleus (Plectranthus scutellarioides ‘Limelight’, Zones 10–11). Let a dark-leaved, low-growing trailer—such as ‘Purple Lady’ bloodleaf (Iresine herbstii ‘Purple Lady’, annual), purple heart (Tradescantia pallida, Zones 8–11), or a purple-leaved sweet potato vine (Ipomoea batatas, Zone 11)—pool around the base, and you have a border or large-container combo that will sail through the dog days and still look lush when fall finally brings us cooler weather once again.
—Nancy J. Ondra is the author of over fifteen books, including Grasses, The Perennial Care Manual, and The Perennial Matchmaker.