Adding Sweet Scents to Your Garden with Annual Phlox

Adding Sweet Scents to Your Garden with Annual Phlox

Annual Phlox is a collaborative group of flowering perennial herbs. They are grown as an ornamental annual in most regions. Annual Phlox plants are adapted to abundant rainfall and frequent light refuges in similar climate conditions. Their loose growth habit allows easy mowing, clipping, or trimming of the foliage.


The annual Phlox has compound green leaves growing up to 4 inches long. The leaves have a white base and wavy edges with a few small teeth on each side. The flowers of the annual phlox bloom from June through August in the Northern Hemisphere but only from April through July in the Southern Hemisphere.

The flower of this plant is shaped like a bell and has five petals that range from white to pale yellowish-green or pinkish-green, depending on their age and location. The flowers may be accompanied by upright stamens called filaments, which are slightly longer than those on other members of the genus Phlox.

Growing From Seed

It would be best to cut existing plants from the same species to grow an annual phlox from seed. This is usually done in spring or early summer when the plants are actively flowering.

The first step is to cut down the parent plant and remove any dead or damaged parts of it before planting it in the soil. Then, place the cutting in a sunny location where it can receive plenty of sunlight for several weeks until it grows roots and produces new shoots.

After about three weeks, the plant should be ready to plant in soil or another container if you want to keep it indoors. You should wait longer before planting if you want more flowers later in the year.

Hardiness Zones

Annual Phlox is a perennial herb that is native to the United States, but it is also found in Canada. Annual Phlox grows best in USDA Hardiness Zones 4, 5, and 6. It tolerates temperatures between 40 and 40 degrees Fahrenheit during the day and 15-30 degrees Fahrenheit at night. Annual Phlox grows in every state except Alaska, where it cannot survive without supplemental heat from other plants or animals nearby.


When potting annual Phlox, plant them in well-drained soil with excellent drainage. The soil should be at least 6 inches deep, and the pH should be between 5.5 and 7.5. In addition, the soil should have enough lime to keep the pH neutral but not too much, as it may cause root rot or dieback of the roots.

Pinch off all but 2 inches of stem from each stem before planting them into the potting mix. This will make it easier for them to root once planted in their new location.

Place your annuals in a plastic bag and into your container with the bottom side up so that water does not run off during watering since this would cause your plant to rot from excessive moisture.

Light Requirements

Phlox is very light-demanding and will benefit from bright to moderate light. It likes its shade but will tolerate some sunlight if a cloche or other structure protects it. The plant likes cool temperatures and medium humidity, so it can be grown indoors in most areas of the country. You can also grow the plant outdoors in a warm area.

Water Requirements

An annual phlox needs a lot of water. Since they are not as drought tolerant as some other plants, giving them enough water to keep them healthy is essential. They will look sickly and won't flower if you don't.

Watering an annual phlox should be done weekly during the growing season or whenever the soil feels dry. These plants need at least 1 inch of water per week, but more is better. When watering your annual Phlox, ensure all the leaves are wet before watering again.

Soil Requirements

The soil requirements for this plant are pretty simple. The best soil for an annual phlox is well-draining, sandy loam with a pH between 6 and 7. This mixture of minerals and nutrients allows the plant's roots to grow without problems. If you have clayey soil or poor drainage, it's best to avoid planting annual Phlox in your garden.


Annual Phlox is one of the easiest plants to grow. It doesn't require much care and will bloom year after year. However, it needs fertilizer to keep healthy leaves and flowers. Annual Phlox is a reasonably heavy feeder and can be fertilized every few weeks during spring and summer. The best time to fertilize this plant is when the soil is warm and moist. You should also avoid fertilizing if there are signs of stress in your annual phlox plant, such as yellowing leaves or wilting flowers on top of the stem.

An annual phlox needs a balanced fertilizer that contains nitrogen, phosphorus, and potassium. If you use granular or liquid fertilizer, ensure they are labeled for annuals.

For desirable results, use a liquid fertilizer with iron (10-10-10 or 8-8-8) at a rate of 1/4 teaspoon per gallon. Apply the fertilizer every two weeks during the growing season.

Pests and Disease Problems

Annual Phlox has many pests and disease problems. The most common pest problem is aphids on the stem, leaf, and flowers. Aphids cause the plant to become covered with honeydew, which can attract ants. If you see a lot of aphids, try spraying with insecticidal soap spray or neem oil. You can also eliminate weeds along with annual Phlox to help keep it healthy and pest-free.

Another common pest problem is whiteflies. These insects suck sap from plants and can result in stunted growth. To control whiteflies, use insecticidal soap spray or neem oil and encourage good air circulation around your plants to reduce moisture build-up in the soil.

When To Plant It

The best time to plant Annual Phlox is after the danger of frost has passed. The plant grows best in full sun but does well in part shade. It can also be planted in containers and enjoyed as an annual.

How To Plant Annual Phlox in Your Garden

You can plant your annual Phlox when the soil is dry enough to dig. Fill a hole with potting soil or an organic potting mix. Water it well and then place the individual plants into their holes at about 3 inches deep and 4 inches apart (this will depend on the size of your plant). Space the plants about 6-8 inches apart each way, so they have room to grow.

Companion Plants

Companion planting is a great way to enhance the growth of your annuals and help them thrive better than they would if left alone. Here are some examples of companion plants that work well with Annual Phlox:

Fennel – helps repel beetles, attracts bees, and helps prevent aphids from attacking the plant.

Corn salad – helps repel insects, attracts bees, and attracts beneficial insects.

Marigolds – discourage aphids from feeding on the plant

Nasturtiums – attract pollinators such as bees and butterflies


Annual Phlox can be pruned in the spring. To remove dead branches:

  1. Use loppers to cut them just above a branch collar.
  2. Use secateurs to cut off the branch below the collar, leaving it attached to the plant.
  3. Once you've removed all the dead branches, clean up any leftover debris and mulch around the plants to keep them neat.


The best way to mulch Annual Phlox is to apply a generous amount of shredded leaves and bark. This will prevent the roots from rotting, which can be problematic if you are not careful. If you do not have enough shredded leaves or bark, use composted manure or grass clippings instead.

Not only is the annual Phlox a perfect garden flower, but it's also a symbol of good luck and prosperity. Whether incorporating this flower into your garden or decorating your home with a bouquet, there are plenty of reasons to rejoice in its presence.