What Do Phlox Seeds Look Like – A General View

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Last Updated on December 29, 2022 by Sharon Vanessa

Most new gardeners need to find out what do phlox seeds look like so they can grow and harvest their own and keep them for the next season.

Phlox (Phlox paniculata L.) is a colorful, sun-loving summer bloomer that keeps its bloom on display for at least 6 weeks in mid-summer. It is available in pastels such as pink, lavender, intense shades of red, rose, purple, and white.

Phlox are perennials.  They are a favorite choice to many people because they have varieties that are either ground cover blooming in early spring to the tall phlox blooming in mid-to-late summer.

Phlox Flower

The plants display many star-shaped colorful flowers when in bloom.  There are so many various types, some native to North America making them available in almost every garden in America. These flowers’ versatility cannot be overlooked.

Phlox Flower

These flowers have outstanding qualities that make them favorable to many.  They include:

  • Low-growing phlox work great as an under-cover
  • Tall phlox works best as a colorful backdrop
  • Medium-height varieties can fill any gaps
  • They all have a lovely fragrance and beautiful blooms
  • They are low maintenance

Some varieties come in bi-colors with a sweet scent. It is possible to save phlox seeds at the end of the season from your mature plants.  You can use these seeds to grow a new phlox garden in the following spring.

What Do Garden Phlox Seeds Look Like?

Let’s first know how a seed pod looks like.  A phlox seed pod is a round welling flower-like pod that contains the seeds inside.  The thin-looking pods do not contain the seeds, rather the fat-looking ones.  The seed pods are few in each flower head so the majority is not seed pods.

The seeds when dry are brown in color and oval in shape.  They easily come off the dried pods without much effort.  Once you remove the dry pods, you can store your seeds in an envelope bag rather than a plastic bag.

A plastic bag attracts mildew while the envelope keeps them dry at all times.  You may also opt to put them in a container and add some rice to keep them dry for a longer period of time.

Harvesting Phlox Flower Seeds

Before you harvest your phlox, be sure to follow these steps to enable you to get mature seeds.

Step 1:  At the end of summer, leave your phlox blooms to remain on the plant after the flowers fade. Choose healthy blooms in order to get healthy seeds.

Step 2:  Allow the phlox to continue growing until the petals drop off and the seed pod that is located behind the petals shrivel and turns brown.  Again, don’t leave the pods for too long as the pod may break and spill the seeds on the ground.

Step 3:  Cut the seed pods from the plant and put them into a paper sack. Place them in a warm, well-ventilated place until they are completely dry.  To test if the seeds are dry, they will break when you poke them with your fingernail.  If you notice they are soft, that means they are not dry enough.

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Step 4: Remove the pods out of the plastic bag and break open the pods. Pick out any large pieces of leaves, stems, or petals and discard them.

Step 5:  Place the phlox seeds in a paper envelope for storage. Remember to write the name, date, and color of the plant on the envelope.  This will give you an idea of what type of seeds you have next season you want to plant them.  Store the seeds in a dark, well-ventilated spot until the next planting season.

How Long Does It Take For Phlox Seeds To Germinate? ///

Seeds should germinate in 5-10 days. Just cover the small seeds, and germinate at 16°-18°C (60°-65°F). Thin or space transplants at 20-30cm (8-12″) apart.Phlox is very easy to grow and maintain, and once it’s established, it’s fairly drought-tolerant.Put in a Warm Dark Location. Place the container in a dark, warm area of the house. Phlox seeds need a temperature of 65 Fahrenheit to germinate. Use a space heater for additional heat, or place a seed heat mat under the seed-raising container.Unlike most plants out there, phlox absolutely requires darkness in order to germinate. Like, complete darkness. Most other seeds require or are OK with being exposed to sunlight, but not phlox – if you sow them on the surface of the soil and exposed to sunlight, they won’t germinate.

Sow annual phlox seeds indoors to get a head start, or you can plant the seeds where you want the plants to grow two weeks before your last spring frost is expected.

When Is The Best Time To Plant Phlox Seeds?

Plant phlox in the spring after the threat of frost has passed, or plant in the fall at least a month before your first frost.Phlox are easy-to-grow perennials that come back reliably every season. Phlox comes in two forms: Garden Phlox (Phlox paniculata) and Creeping Phlox (Phlox subulata). Both Garden Phlox and Creeping Phlox produce fragrant blooms that attract a variety of pollinators, including butterflies and hummingbirds.It spreads slowly, growing in mounds that get 4–6 inches thick. The whole plant turns into a carpet of color in spring, when flowers cover every square inch of foliage.Annual phlox dislikes root disturbance, so direct sow in spring, as soon as the ground can be worked. Otherwise, start indoors in coir or peat pots 4-6 weeks before the last frost date, and then carefully transplant outdoors when the first true leaves appear. Seeds should germinate in 5-10 days.

How Many Phlox Seeds Per Pot?

Depending on the pot size, 2 to 4 seeds is ideal.

Seed Spacing: Plant or thin 1′ apart in dryer conditions; 2′ in humid regions or when planting in consistently-irrigated beds.Garden phlox should be planted about 18 inches apart, while Creeping phlox should be planted about 2 feet apart. Giving these plants lots of room for air circulation is the key to limiting the appearance of mildew. (Although most varieties available today have been bred to resist mildew.)Plant each of your seeds 1/8 of an inch deep in the potting soil. Separate them by 1 inch each. Then, lightly cover them with soil.When growing perennial phlox from seeds it is best to do so outdoors. Sow the seeds into flats, and lightly cover the seeds

Phlox makes a great container plant. Creeping varieties are a good choice for the spiller role in container gardens. Tall phlox may be used as the thriller role, but their height may limit them for use in only larger containers.Be sure the container has at least one drainage hole in the bottom. Allow at least 6 inches (15 cm.) between each plant so the creeping phlox has room to sprawl. Add a small amount of all-purpose fertilizer if the potting mix doesn’t have fertilizer pre-added.

Can You Plant Phlox Seeds In Fall?

Phlox can be planted in spring or fall, and should be planted immediately upon receiving. Light: Both varieties of phlox enjoy full sun, although the upright Garden phlox can take a little afternoon shade, particularly in the south.While container plants tend to dry out faster than those grown in beds, and therefore should be watered more frequently, phlox withstands short periods of drought. Still, we recommend consistently moist soil when possible.

Phlox is a sun-loving plant, but it likes a little afternoon shade in the hottest climates. Ceramic containers tend to absorb a lot of heat, so we recommend placing potted phlox where it can be out of the sun in late afternoon.

Peak summer temperatures will cause annual phlox to turn brown and drop its flowers, but if you deadhead them and cut the stems back by about 60%, chances are good they’ll get a second wind later in the season.Don’t fuss too much about soil quality. Phlox thrives in poor to medium soils, as long as it drains well. You can plant it in consistently-irrigated beds, too, with careful spacing. Prepare the soil with plenty of aged compost to improve drainage, and throw in a little peat moss or similar acidic material; phlox likes its soil on the slightly acidic side with a general pH between 6.0 and 8.0.


Identifying phlox seeds is the first step towards harvesting your own and saving them for the next season.  If you don’t know what the seeds look like, the video attached herein will be of great help to you.

Remember not to leave them for too long on the plant as they may end up falling and begin growing again, rather harvest them at the right time.

Learning how to save your own seeds will save you from spending more money on new seeds next season you want to grow them.  It also enables you to grow the same great flowers you had in the past season especially if they matched well with the climate and soil of your area.

Now that you know what do phlox seeds look like, go ahead and harvest your own following the steps above.  Then you can laugh your way to the garden next season and grow your amazing phlox flowers.

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