How to Grow and Care for Night Sky Petunia

closeup of dark purple petunia flower with white spots like stars on its petals

Samantha Locking/Getty Images

Petunias come in an incredible range of colors, but night sky petunias might be the most breathtaking. Big blooms in shades of deep purple, red, burgundy, and pink are spangled with white flecks to create an effect not unlike looking up at a beautiful starry sky.

Plant these gorgeous, low-maintenance flowers in flower beds, containers, or hanging baskets. The blooms start in summer and can last until the first frost in autumn. Here's everything you need to know about growing night sky petunias in your garden.

  • Botanical Name: Petunia 'Night Sky'
  • Common Name: Night sky petunia, starry sky petunia, galaxy petunia
  • Plant Type: Herbaceous perennial
  • Mature Size: 14 inches tall and 30 inches wide
  • Sun Exposure: Full sun
  • Soil Type: Moist, well-drained soil
  • Soil pH: 5.5 - 6.0
  • Toxicity: Nontoxic

Plant Care

Proper watering is key to keeping night sky petunias happy and flowering. Whether planting them in the ground or a container, you'll want to keep the soil evenly moist but not soggy. Check the soil occasionally, and if it feels dry to the touch, it's time to water. Night sky petunias may need more water than usual during hot, dry periods if planted outdoors.

Feed night sky petunias planted in the ground about once per month with organic fertilizer according to product directions. Those kept in containers or hanging baskets will benefit from receiving a slow-release, balanced fertilizer every couple of weeks.

As your night sky petunia's blooms fade, pinch off the dead flower heads. In addition to keeping your plants looking neat and tidy, regular deadheading helps promote new blooms.

red night sky petunia with white spots and green leaves

ewa saks/getty images

Best Growing Conditions for Night Sky Petunia

Plant night sky petunias in a place with rich, well-drained soil. They need full sun, at least six hours of sunlight per day, to bloom properly. The plants grow best in temperatures ranging from around 65 to 85 degrees.

Types of Night Sky Petunia

Ever since plant breeding company Selecta One developed the night sky petunia in 2015, they've introduced new color variations on the cultivar. These include Electric Purple Sky, featuring fuchsia petals with a white star pattern; Midnight Sky, with a rich, reddish dark purple; Crystal Sky, which has white spots over pale purple petals with dark purple veining; and bright red Strawberry Sky.

How to Propagate Night Sky Petunia

It's easy to propagate night sky petunia from stem cuttings. Take cuttings in the spring or early summer when the plant is actively growing.

What You'll Need

  • Healthy, mature plant
  • Sharp, sterilized scissors or pruners
  • Small plant pot
  • Soilless growing medium or seed starting mix
  • Rooting hormone powder

Step 1: Fill your pot with growing medium and water it well. Make a hole two to three inches deep with your finger or a pencil.

Step 2: Choose a healthy stem from the mother plant with several leaves. Make a diagonal cut just below a leaf node six inches from the stem tip. Trim away any leaves growing on the bottom third of the cutting.

Step 3: Dip the bottom tip of the cutting in rooting hormone powder. Plant the cutting in the pot so that the nodes of the leaves you trimmed away are below the soil line.

Step 4: Place the cutting in a warm place with bright, indirect light. Keep the growing medium moist but not soggy. In three to four weeks, the cutting will be rooted, and you should see new leaf growth. Transplant and care for your new night sky petunia as usual.

purple night sky petunias in garden

Irina Gelwich/Getty Images

Common Problems With Night Sky Petunia

The best way to avoid problems with your night sky petunias is to plant them in a site with the proper growing conditions and catch potential issues early. Like other types of petunias, they are susceptible to issues like insects. You can treat pests such as aphids with organic pesticides like neem oil.

Overwatering and underwatering can also cause night sky petunias to wilt or grow yellow or brown leaves. Yellowing leaves can also indicate a nutrient deficiency, so if you're watering properly but haven't fed your plants in a while, fertilizing could help.

How to Get Night Sky Petunia to Bloom

Ensure that your plants get at least six hours of sunlight per day for abundant flowers. Plants that receive consistent water, sunlight, and fertilizer will be more likely to put forth abundant blooms.

Deadhead spent blooms by pinching them off to encourage new growth. Light pruning in midsummer and early fall can also stimulate new growth and more flowers. Be sure not to cut away more than 20 percent of the plant's growth with each pruning.


Is Night Sky Petunia Easy to Care For? 

Yes. With ideal growing conditions and basic maintenance, night sky petunia is easy to care for.

How Long Can Night Sky Petunia Live? 

Night sky petunias are annuals, so they'll last for one growing season and die back in the winter. You'll need to plant new plants in the spring.

Can Night Sky Petunia Grow Indoors?

Yes, with the proper conditions. Night sky petunias require at least six hours of sunlight per day to flower, so keep them in a sunny, south-facing window or use an LED grow light to give them what they need.

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