Garden phlox (Phlox paniculata) is a hardy, long-lived perennial with a romantic charm. From midsummer to early fall, the sturdy, upright plants are topped with large clusters of fragrant flowers that come in a fantastic range of colors including white, pink, fuchsia, red, lavender, purple and orange as well as dozens of eye-catching bicolors. The sweet-smelling, nectar-rich blossoms attract butterflies and hummingbirds and are beautiful in summer flower arrangements.
STEP 1 - KNOW
START WITH A BETTER BULB
When you compare two phlox plants side by side, it’s easy to see differences in quality. Longfield Gardens supplies grade #1 plants (shown at far left) with strong, healthy root systems. The bigger the plant, the faster it will settle into your garden and the sooner it will flower.
STEP 2 - PLAN
SUN AND SHADE: Phlox may be grown in full sun or partial shade. The plants will produce more flowers when they are grown in full sun.
ZONE: Garden phlox are winter hardy in zones 4 to 8.
SOIL CONDITIONS: Phlox should be planted in fertile, well-drained soil where the plants will get consistent of moisture throughout the summer.
WHEN TO PLANT: Plant phlox in spring when the weather is cool and the soil is moist.
WHERE TO PLANT GARDEN PHLOX
PERENNIAL GARDENS Garden phlox make great companions for other summer-blooming perennials such as lilies, bee balm, rudbeckia, Shasta daisies, yarrow, clematis, and daylilies. In flowerbeds, the taller cultivars provide a good backdrop for shorter plants.
CUTTING GARDENS The long, stiff stems of garden phlox are easy to arrange in a vase, where they complement and help hold up other flowers such as dahlias and lilies. Cutting the stems while some of the flowers are still in bud will extend their vase life.
STEP 3 - GROW
PLANTING IS AS EASY 1-2-3
1. Loosen the soil 12” and mix in several handfuls of compost and ¼ cup of all-purpose granular fertilizer (follow package directions).
2. Put the phlox in the hole so the crown of the plant (where the roots meet the stem) is right at the soil line.
3. Cover the roots with soil and water well.
PLANTING TIPS FOR PHLOX
Phlox need a consistent supply of moisture and will not tolerate drought. Before planting, add compost or other organic matter to enrich the soil and increase its ability to hold moisture.
Phlox should receive about 1” of water per week throughout the growing season. To keep the foliage as healthy as possible, water at the root zone and avoid wetting the leaves. Mulching around the plants with compost or shredded leaves will help keep the soil moist and reduce weeds.
Garden phlox is susceptible to a fungal disease known as powdery mildew. Though this disease rarely harms the plant, it can cover the foliage with an unattractive white dust. Powdery mildew is most troublesome in warm, humid weather. To minimize the problem, encourage good air circulation. This will help reduce infection rates by keeping the foliage as dry as possible.
To get bushier plants with more flower heads, you can pinch back the growing tips when the plants are 6 to 8” tall.
STEP 4 - AFTERCARE
CARING FOR PHLOX AFTER THEY BLOOM
After the flowers have faded, cutting off the spent flower heads will often promote a second flush of flowers. It also keeps the plants from self-sowing (volunteer seedlings will be inferior to the parent plant and should be treated as weeds). In the fall, cut back all stems to the ground and remove them from the area to help minimize future disease problems.
Fertilize garden phlox in early spring. Spread granular all-purpose fertilizer around the base of the plant, following package directions. Top dressing the plants with a couple inches of compost will add nutrients and help improve the soil.
When garden phlox becomes overcrowded, flower production starts to decrease. To maintain a good show of flowers, you may need to divide the plants every 3 to 4 years. As long as the plants continue to flower well, there’s no hurry to divide them.