To review the February newsletter CLICK HERE
GardenSMART Newsletter Signup
Visit our Sponsors! encore azalea Dramm
Visit our Sponsors and win.
Plant Phlox for All-Season Color

Plant Phlox for All-Season Color

By Susan Martin for Proven Winners
Photographs courtesy of Proven Winners

The genus Phlox is an incredibly diverse group of flowering plants that includes everything from low growing groundcovers to billowy plants for containers, hip-high perennials and several more types in-between. Most have roots in generations of native species that can be found growing throughout the Midwest, East Coast, Southeast, north to Ontario and Quebec, and south into Texas.

GardenSMART Article Image

Luminary™ ‘Ultraviolet’ and ‘Opalescence’ tall garden phlox light up this sunny border in midsummer.

It’s not surprising, then, to learn that the bloom times of all these different phlox species varies tremendously. By planting a few of each type, you can have some blooming from early spring all the way into fall.

Why would you want to extend the phlox show? Their flowers are beautiful and often fragrant, so they are a delight to have in bloom. But just as importantly, a wide variety of pollinators including bees, butterflies, moths, hummingbird moths and hummingbirds enjoy phlox, too. When phlox are always in bloom, they provide a continuous nectar source for these important insects and birds.

GardenSMART Article Image

Plant spring blooming phlox like ‘Purple Sprite’ someplace where you will appreciate the early show of color they provide in the landscape.

Spring Blooming Phlox

As the first to bloom in early to mid-spring, the Spring Bling™ series of hybrid creeping phlox usher in the new season even earlier than traditional creeping phlox. While much of your garden is still fast asleep, this phlox is a shining beacon in the landscape. Its low growing, mounded foliage becomes completely obscured with relatively large, bright pink or lavender flowers for many weeks, kicking off the new season in style. Varieties in this series include ‘Pink Sparkles’, ‘Rose Quartz’ and ‘Ruby Riot’.

Shortly after Spring Bling phlox come into bloom, Mountainside® ‘Crater Lake’ and ‘Majestic Magenta’ hybrid spring phlox begin. Tulips and other mid-spring blooming bulbs often flower in unison with Mountainside phlox. This is a groundhugging plant that spreads slowly, maintaining its refined shape all season. Try tucking a few in between stepping stones on a path or along the edge of a rock garden.

By mid to late spring, Sprite hybrid spring phlox are on full display with their bright pink or lavender blooms adorning the 6-8” tall mound of bright green foliage. They are perfect for the front of the border or edging a sunny pathway along with catmint, sedum and other low growing perennials.

These types of phlox prefer full sun, neutral pH soils and average to drier soils. Good drainage is essential for keeping their roots healthy. Just after they are finished blooming, shear the plants back to tidy them up and clean up any brown foliage to encourage them to grow denser. In zones 4-8, these types of spring blooming phlox typically grow 4-8” tall and 18-28” wide.

GardenSMART Article Image

Intensia® annual phlox has the distinct advantage of blooming non-stop from planting time until frost. It works well in containers and landscapes as long as the soil is well-drained. Find it blooming in three colors.

Annual Phlox

Once the cool, rainy weather subsides, it will be time to plant Intensia® phlox. Unless you live in zone 10 or warmer, this species will be an annual for you, meaning you’ll want to replant it each year. Unlike all the other types of phlox described here, Intensia is the only one that blooms non-stop without deadheading from planting time until frost. That fact alone makes it worthy of replanting, but you’ll also love how easy it is to grow.

This is a super heat resistant species and can even take some drought once its roots get established. It needs well-drained soil to thrive, so if you have heavy clay soil, you’ll want to plant it in a raised bed or containers. Plentiful sunshine will help to keep it in bloom all season.

Intensia phlox comes in patriotic shades of red, white and blue. You could plant up all three together in your porch pots or choose one of them to line the sunny path to your front door. They grow 10-16” tall and wide in a single season and play the role of filler in container recipes.

GardenSMART Article Image

‘Opening Act Ultrapink’ hybrid summer phlox is blooming beautifully here with Dolce® ‘Wildberry’ coral bells in early summer.

Hybrid Summer Phlox

One of the newest types of phlox available are hybrid summer blooming phlox. Created by crossing several native species with a goal of retaining the best traits of each, the resulting cultivars make excellent garden plants. They bloom early for an upright phlox, are great rebloomers and have strong resistance to powdery mildew.

Opening Act varieties are a shining example of hybrid summer phlox. They flower in shades of white, pink and lavender in waves beginning in early summer, lasting well into midsummer and reblooming into early fall. When not in bloom, their glossy, deep green, narrow leaves provide an interesting texture for the landscape.

These phlox initially form a 18-26” tall clump, but then slowly spread and the clump expands to 24-32” wide. The result over time is a full, dense plant that is packed with flower power. Even in warm, humid climates, they have proven to hold up admirably. Grow them in full sun to light shade in zones 4-8.

GardenSMART Article Image

Luminary™ ‘Sunset Coral’ tall garden phlox draws in pollinating bees, butterflies and hummingbirds from midsummer into fall.

Summer to Fall Blooming Tall Garden Phlox

The latest blooming phlox may be the species you are most familiar with. Cultivars like ‘David’, ‘Nicky’ and ‘Bright Eyes’ have graced gardens for decades in zones 3-8. If they have one fault, it is that powdery mildew seems to be most prevalent in this species, especially in areas where nighttime temperatures and humidity remain high all summer. Growing them in a sunny to partially sunny spot where there is good airflow between plants helps prevent mildew. Breeders have been working to cultivate more resistant varieties with some success.

The Luminary™ series is a great example of tall garden phlox that exhibits resistance to powdery mildew. Blooming in shades of pink, coral, magenta and white, they form large panicles of fragrant blooms atop tall stems from midsummer into fall. Their deep green foliage and strong, 30-36” tall stems that don’t need staking make them attractive garden plants for the middle of the border even when they aren’t in bloom. Varieties in this series include ‘Backlight’, ‘Opalescence’, ‘Sunset Coral’ and ‘Ultraviolet’.

By selecting at least one phlox from each of the categories described above, you can have phlox flowers gracing your garden from early spring into fall. Spring and fall are both excellent times of year to plant phlox. Look for them at your local garden centers next spring.

Stay up to date with Proven Winners on Facebook, Instagram, Pinterest, YouTube and Twitter.

Patent Information: Luminary™ 'Ultraviolet' Phlox paniculata USPPAF CanPBRAF; Luminary™ 'Opalescence' Phlox paniculata USPP33295 CanPBRAF; 'Purple Sprite' Phlox USPP31272 CanPBRAF; Spring Bling™ 'Pink Sparkles' Phlox USPP33276 CanPBRAF; Spring Bling™ 'Rose Quartz' Phlox USPP33315 CanPBRAF; Spring Bling™ 'Ruby Riot' Phlox USPP34223 CanPBRAF; Mountainside® 'Crater Lake' Phlox USPPAF CanPBRAF; Mountainside® 'Majestic Magenta' Phlox USPP33006 CanPBRAF; 'Opening Act Ultrapink' Phlox USPPAF CanPBRAF; Luminary™ 'Sunset Coral' Phlox paniculata USPPAF CanPBRAF; Luminary™ 'Backlight' Phlox paniculata USPPAF CanPBRAF; Luminary™ 'Opalescence' Phlox paniculata USPP33295 CanPBRAF; Luminary™ 'Ultraviolet' Phlox paniculata USPPAF CanPBRAF

Susan Martin is an avid zone 6 gardener, garden writer and speaker who enjoys spreading her passion for plants to her fellow gardeners across North America.

All articles are copyrighted and remain the property of the author.

Article URL:

Back to Articles List                               

GardenSMART Featured Article

By Heirloom Roses
Photographs courtesy of Heirloom Roses

In many areas of the country this is an excellent time to prune roses. Although rose pruning may seems daunting, it’s not hard to learn and the results are well worth the effort. For an informative article on rose pruning, click here .

  Click here to sign up for our monthly NEWSLETTER packed with great articles and helpful tips for your home, garden and pets!  
Copyright © 1998-2012 GSPC. All Rights Reserved.