Phlox (Phlox paniculataor tall garden Phlox)

Don’t discount Phlox as a “grandma” plant that comes down with terrible mildew in late summer. There are so many mildew-resistant varieties to choose from, you will have trouble deciding which ones to grow. One new variety that holds onto its blooms the longest is ‘Maiden America’, a two-footer that comes into bloom in mid-July and stays that way for a month. Check out Perennial Pleasures Nurseryin East Hardwick, Vermont, an online and on-site nursery that specializes in Phlox.

According to When Perennials Bloomby Tomasz Anisko, some of the varieties that bloom late in the season include ‘David’, ‘Eva Cullum’, and ‘Norah Leigh’. Whether you want blooms in early July or late August, it’s a good idea to cut the plant back by a third some time in early June. This encourages branching, which means the plant will have more flowers.

GROWING TIPS: Mildew resistance doesn’t mean mildew-proof, so good cultural practices are a good idea no matter what varieties are used. Give the plant good air circulation, and be prepared to supplement its moisture at the root zone, not the leaves. In the spring, remove all but about five strong stems at ground level.

Phlox     Photo: Jean Starr

Helenium

Unfairly referred to as “sneezeweed,” Heleniumgets a head start on autumn russets and golds, typically beginning its bloom in mid-August. The plants have daisy-like flowers with adorable raised button centers. Thanks to hybridization, plants can be found from two feet to five feet tall, with shorter varieties tending to bloom earlier in the season. Warm climates and rich soil could contribute to the taller varieties flopping, so those over three feet tall might need to be staked.

For those with smaller gardens, the Mariachi Series of Helenium is ideal. Varieties in this dwarf group go by names that include Helenium ‘Salsa’, ‘Bandera’, ‘Fuego’, and ‘Siesta’. Both ‘Carnival’ and ‘The Bishop’ stage an in-between show at just three feet tall.

GROWING TIPS: Helenium is prone to a bit of mildew on its lower stems. Cover them up by planting something shorter in front of it to hide the bare stems.

Helenium     Photo: Jean Starr