Phlox Full Growing Guide: Everything You Need to Know

how to plant phlox

If you want to add a splash of dramatic color to your garden beds that will return year after year, look no further than phlox. Also known as “garden phlox” or “summer phlox,” this easy-to-care-for plant is perfect for borders and can thrive anywhere in your garden.

At MyGardeninn, we want to make you a phlox expert. In this in-depth growing guide, we will cover everything you need to know about planting and caring for phlox. From the ideal growing conditions to different varieties and when to plant them, get ready to become a pro in growing phlox.

What Are Phlox?

Let’s start with the basics. Phlox is a genus of plants in the Polemoniaceae family, with 67 different species and countless cultivars to choose from. The name “phlox” comes from the Greek word for “flame,” which perfectly describes the intense and vibrant colors of these plants.

As you explore different types of phlox, you’ll find two main categories: upright phlox and mat-like phlox. The mat-like forms of phlox are excellent ground cover options that spread quickly and are easy to manage.

Where Do Phlox Grow?

Most phlox species are native to North America, with one species found in Siberia. These plants can tolerate a wide range of climates and are found in various environments worldwide, from prairies to tundras. Phlox is truly a versatile plant that can adapt to different conditions.

Why Grow Phlox?

There are several compelling reasons to add phlox to your garden:

  • Versatility: Whether you want a carpet of flowers, elegant borders, or taller upright plants with fragrant flower clusters, phlox has a variety for every garden gap.
  • Beautiful Cultivars: Phlox comes in many colors, including varieties with petals featuring multiple hues.
  • Year-Round Beauty: Evergreen phlox has needle-like foliage that adds beauty to your garden throughout the seasons.
  • Pollinator Attraction: Bees, hummingbirds, and butterflies are drawn to the fragrant flowers of phlox, making it a pollinator-friendly choice.
  • Great for Bouquets: Cut phlox flowers make excellent additions to bouquets, filling your home with their fragrance and vibrant colors.
  • Extended Bloom Period: Phlox flowers can bloom for weeks, providing you with enduring pleasure.

Recommended Phlox Varieties

There is a wide range of phlox varieties to choose from, each offering different colors and characteristics. Here are some popular options to consider:

  • Emerald Blue: A lilac-colored creeping phlox variety that works well as ground cover.
  • Blue Paradise: A purplish variety with mildew resistance, making it suitable for humid climates.
  • Orange Perfection: A fiery orange phlox variety reminiscent of flames.
  • Candy Stripe: A creeping cultivar with pink and white candy-striped flowers.
  • Peppermint Twist: A tall variety with pink pinwheel-like clusters of flowers.
  • David: A form of tall phlox with white flowers.
  • Jeana: A tall phlox variety with small purplish flowers.
  • Bright Eyes: A variety with bright pink flowers and contrasting dark centers.
  • Nicky: A fragrant cultivar with darker pink blossoms.
  • Coral Flame: A dwarf cultivar with vibrant coral-red flowers.
  • Flame White Eye: Phlox flowers with white petals and pink centers.
  • Purple Beauty: A variety with purple blooms and bold dark centers.
  • Nora Leigh: Light pink phlox blossoms with darker pink centers.
  • Volcano Ruby: A versatile, mildew-resistant variety suitable for southern climates.
  • Grenadine Dream: A reddish phlox variety with globe-like clusters of flowers.
  • Little Boy: A low-growing variety with dark purple petals that fade to white.
  • Jubilee: A hue similar to Orange Perfection, but more prone to powdery mildew in humid climates.

These are just a few examples of the many phlox cultivars available. Explore further to discover pale lavender-blue flowers, jewel-tone blooms, and more.

When Do Phlox Bloom?

Phlox blooms in the spring and summer, providing bursts of color during these seasons.

How Long Do Phlox Bloom?

One of the best things about phlox is their extended bloom period. Tall garden phlox (Phlox paniculata hybrids) can bloom for up to six weeks or more, with some varieties starting in mid-summer and others blooming into late August.

When to Plant Phlox

You have two options for planting phlox: spring or autumn. If you choose spring planting, make sure the last frost date has passed. For fall planting, ensure your phlox has enough time to establish before the first frost.

Ideal Growing Conditions for Phlox

To help your phlox thrive, provide the following growing conditions:

Sun Requirements

Phlox prefers full sunlight for the most abundant blooms. However, they can also tolerate partial shade. Keep in mind that more sun reduces the risk of diseases in phlox. Good airflow is also essential to prevent disease, so ensure they are not crowded against walls or barriers.

Soil Type

Phlox thrives in moist, well-draining soil with a pH range between 5.7 and 7.5.

Watering Needs

Water your phlox regularly to keep the soil consistently moist. Avoid wetting the leaves to prevent disease.

How to Plant Phlox

Now that you know the ideal conditions for growing phlox, it’s time to learn how to plant these beautiful flowers.

Container Planting

If you prefer container gardening, phlox, especially creeping varieties, can be grown in pots. Follow these steps to transplant your phlox into a container:

  1. Choose a suitable container slightly larger than the original one. Ensure it has drainage holes.
  2. Add potting soil mixed with all-purpose fertilizer to the container, leaving enough space for the phlox plant.
  3. Carefully remove the phlox from its original container and transfer it to the new pot, filling it with soil so that the top of the root ball is just covered.
  4. Water the newly transplanted phlox deeply to help it adjust.
  5. Find a suitable location for your potted phlox, ensuring it receives full or partial sunlight. Avoid growing phlox indoors, as they tend to spill over the sides and are better suited for decks or patios.

Ground Planting

If you want to plant phlox in your garden bed, follow these steps:

  1. Choose a suitable spot that receives ample sunlight and has moist, well-draining soil.
  2. Prepare the soil by tilling it and adding compost.
  3. Dig a hole large enough to accommodate the phlox plant. If you’re transplanting from a pot, make sure the top of the root ball is level with the soil surface.
  4. Plant the phlox in the hole, ensuring the roots are covered with soil. Water thoroughly.
  5. Space each phlox plant 1-3 feet apart.
  6. Water the phlox regularly to keep the soil moist.

Starting Phlox from Seeds

If you prefer starting phlox from seeds, follow these steps:

  1. Start seeds indoors approximately eight weeks before the last frost date.
  2. Use a tray with drainage holes and fill it with potting soil, leaving some space at the top.
  3. Plant the phlox seeds ⅛ inch deep in the soil, spacing them 1 inch apart. Lightly cover them with soil.
  4. Use a spray bottle to keep the top of the soil slightly damp. Cover the tray with plastic wrap, ensuring it doesn’t touch the soil.
  5. Place the tray in a dark location with a temperature around 65°F for germination. Check the soil frequently and spray water to maintain moisture.
  6. Once the seeds germinate (within 5-10 days), remove the plastic wrap and move the tray to a sunny spot. Continue to spray water to keep the soil moist.
  7. After the last frost, transplant the phlox seedlings outdoors, providing 12-36 inches of space between plants.

Starting Phlox from Cuttings

If you have an existing phlox plant, you can propagate it from cuttings. Follow these steps:

  1. Dig up a phlox plant during the winter to expose its roots.
  2. Take root cuttings from larger roots, around 4 cm in length, cutting them near the stem.
  3. Plant the cuttings in the same orientation you found them, with the end nearest the stem pointing upward.
  4. Water the cuttings after planting.
  5. Come spring, new shoots should begin to form.

Dividing Phlox Plants

To propagate your phlox, divide the plants every few years. Here’s how:

  1. During spring, carefully unearth the phlox plants.
  2. Separate the plants and replant them.
  3. With proper care, they should blossom in the same summer.

How to Care for Phlox

Caring for phlox involves fertilizing, mulching, and pruning. Follow these guidelines to keep your phlox healthy and vibrant:

Fertilizing Phlox

Phlox responds well to fertilizer, especially a balanced formula like 10-10-10. Apply it in the spring when you see new growth and again at the start of the blooming period.

Mulching Phlox

If you plant phlox in the fall, protect it while it establishes by adding 4-6 inches of mulch over the soil when it freezes. Straw, pine needles, or other mulching materials can be used. Consider mulching in subsequent years to protect against winter cold and early spring growth.

Staking Phlox

Taller varieties of phlox may require staking, especially in windy or rainy climates. Set up stakes as the plants grow and tie them for support.

Pruning and Deadheading Phlox

Deadheading (removing spent or faded flowers) can encourage more blooms and prevent self-seeding. Use shears to remove withered flower clusters, supporting the growth of new ones. In autumn, cut back tall phlox plants to 1-2 inches from the ground after the first frost. Creeping phlox is evergreen, so it doesn’t require cutting back.

Disease and Pest Concerns

Phlox can be vulnerable to diseases like powdery mildew, rust, leaf spots, and stem canker. To prevent these, ensure proper air circulation by adequately spacing the plants and avoiding excess water on the foliage. Choosing mildew-resistant varieties can also help. Watch out for pests like stem nematodes, caterpillars, deer, snails, and slugs.

Recommended Companion Plants for Phlox

Phlox pairs well with a variety of other flowers, providing stunning combinations in your garden. Consider these companion plants:

  • Zinnias: Colorful companions for tall phlox.
  • Rock Cress: A mat-like plant that complements creeping phlox.
  • Cushion Spurge: Produces yellow spring flowers, contrasting with phlox in the fall.
  • Grape Hyacinth: Provides different textures alongside phlox.
  • Basket-of-Gold: Evergreen plant that spills over containers or rocks.

These are just a few examples—there are many more companion plants to discover and experiment with.

Frequently Asked Questions About Growing Phlox

Still have questions about growing phlox? Check out our FAQ section.

Where to Buy Phlox

Ready to add the beauty of phlox to your garden? Browse our colorful varieties of tall and creeping phlox here and get started on your phlox-growing journey.

Note: All images used in this article are from the original source.

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