Rose mallow (Hibiscus moscheutos)

This hardy hibiscus looks more like its exotic cousin, with its huge, bright flowers. But rose mallow is not only hardy to Zone 5, it is an American native. Newer hybrids are compact, usually growing no more than three feet tall by four feet wide; and have more flowers than the older varieties. New introductions began to hit the garden centers right after the turn of the century. These have included larger, thicker, ruffled and bi-colored flowers on stems more substantial, with better branching and darker leaves.

Hibiscus SUMMERIFIC ‘Perfect Storm’ came on the scene in 2016, a more compact version of a previous variety called ‘Summer Storm’. The latest introduction by Proven Winners is SUMMERIFIC ‘Holy Grail’, boasting the best combination of all–deep red flowers, compact size and mahogany leaves.

GROWING TIPS: According to Walters Gardens, keeping Hibiscus hybrids watered will result in larger flowers and lush foliage. Deadheading will improve the appearance of the plant. Hibiscus is always one of the last late summer perennials to emerge in spring, so don’t assume you’ve lost it and dig it up.

Hibiscus     Photo: Jean Starr

Butterfly bush

Buddleia(pronounced BUD-lee-uh) is in the category called a subshrub, because, although it has the appearance of a shrub, in areas with very cold winters, it dies back to the ground and sprouts again in the spring. New hybrids have been bred for smaller size, bigger flowers and sturdier stems.

The Lo & Behold series by Proven Winners features a variety of very hardy plants that reach less than two feet tall, making them perfect to plant on a slope or at the feet of a tall hummingbird and butterfly magnet like Salvia ‘Amistad’. One of my favorites has been Buddleia Monarch ‘Prince Charming’, its bright pink color unusual in Buddleia.

GROWING TIPS: Leave the stems on the plant through the winter and wait until you see new growth from below ground before pruning them off. In years with mild winters, Buddleia can sprout from the previous season’s stems. However, it’s best to prune it back to encourage a bushier plant and more blooms.

Buddleia     Photo: Walters Gardens

 Final Thoughts on Favorite Late Summer Perennials

All these perennials will return with little encouragement. Most prefer to be planted in the spring, when the temperatures are cooler and they can become established well before their performance is scheduled. Think ahead when you buy your plants in the spring, or visit garden centers in late summer to find some of these plants in pots and ready to plant.