News Gardening Trends How to Plant and Grow Night Sky Petunia With its white starry speckles, this gorgeous purple petunia is nothing short of otherworldly. By Andrea Beck Andrea Beck Andrea Beck served as garden editor at BHG and her work has appeared on Food & Wine, Martha Stewart, MyRecipes, and more. Learn about BHG's Editorial Process and Sharon Greenthal Sharon Greenthal Sharon is a writer and contributor at Better Homes & Gardens, where she writes, edits, and updates content on the website, refreshing recipes and articles about home design, holiday planning, gardening, and other topics. Before joining Better Homes & Gardens, Sharon began her career as a blogger, then became a freelance writer, focusing on home design and organization, midlife and empty nesting, and seniors and eldercare. Her work has been published on a range of websites, including Angi, Purple Clover, HuffPost, Grown and Flown, Seniors Matter, AARP’s the Girlfriend and the Ethel, and many other outlets. Learn about BHG's Editorial Process Updated on April 17, 2024 In This Article View All In This Article Where to Plant Planting Tips Care Pests and Problems Propagation Types Companion Plants FAQ Petunias are valued for their ability to bring long-lasting color to your garden or patio in the summer. Night Sky petunias, hardy in Zones 10-11, have vivid purple petals speckled with white, giving them a dappled, otherworldly appearance. Sometimes called galaxy flower or 'Starry Night' petunia, thanks to its resemblance to the cosmos, this variety is relatively new—it was introduced in 2016. Petunias are annuals, so they last only one growing season. Once they're blooming, they'll continue flowering for months until the first fall frost. Courtesy of @stabilityfarmgreenhouse Where to Plant Night Sky Petunia Petunias are drought-tolerant, but they don't like soggy soil, so be sure to choose a well-drained spot. If you plant them in a container or hanging basket, let the top of the soil dry to the touch before watering, keeping in mind that some planters may require watering every day. How to Make a Hanging Basket for Your Front Porch or Patio How and When to Plant Night Sky Petunia Near-constant blooming uses up lots of energy, so petunias need to be planted in rich, nutrient-dense soil with plenty of organic matter. If you want to start seeds yourself, follow the instructions on the seed packet—typically, they need to get growing by late February. If you prefer to buy flowers, most growers start shipping them in May, when many parts of the country have already had their final spring frost. For most regions, mid-May to early June is the best time to plant these one-of-a-kind petunias outside. To plant nursery specimens in the ground or in a container, dig a hole about the same width and depth as the planting container. Remove the plant and loosen the roots a bit from the root ball before placing in the hole. Backfill with soil, tamp lightly, and water well. Night Sky Petunia Care Tips Night sky is easy to care for and needs little pruning or special attention. Light Plant Night Sky petunias in a spot with full sun, where they'll get at least six hours of direct sunlight daily. If there is any less, your plants will likely produce fewer flowers. Soil and Water Night Sky petunias will grow in just about any type of soil, as long as there's good drainage and it's rich in organic components. The organic soil's nutrients will help them continue blooming throughout the season. Don't overwater in-ground Night Sky petunias, or their stems will grow weak. When the weather is hot, water once a week, adding 1 to 2 inches of water. Hanging baskets and containers will need more water due to extra drainage and greater exposure to heat and wind. The 6 Best Watering Wands of 2024 to Keep Your Garden Green Temperature and Humidity Nighttime temperatures of 55 to 65°F and daytime temperatures between 60 and 80°F are ideal for these plants. When winter starts, they'll quickly succumb to the cold weather. Fertilizer Fertilizing them regularly will help the plant keep producing flowers; use a balanced 10-10-10 fertilizer, following manufacturer's instructions, every two weeks for containers and every three weeks for garden petunias. Pruning Keep your Night Sky petunias growing and flowering by deadheading them regularly and trimming leggy stems. Potting and Repotting 'Night Sky' Petunia When Night Sky petunias begin to grow out of their pots, it's time for repotting. Don't use a container that's too large, as this can leave plants vulnerable to root rot. Choose a ceramic or terra-cotta pot with good drainage, and carefully remove the entire plant from its existing pot, keeping the root intact. Water the plant in its new container. Pests and Problems Night Sky petunia plants can be bothered by aphids, whiteflies, and slugs. Mix 1 to 2 tablespoons of liquid dish soap in 1 gallon of water and spray plants to rid them of these garden pests. Botrytis (a gray mold fungus) can develop when these plants get too much water. Good drainage in containers will help prevent this. Always wait until the top of the soil dries out before watering. How to Propagate Night Sky Petunia Night Sky petunia is a patented plant variety and cannot be propagated legally. Types of Night Sky Petunia Starry Sky Burgundy Petunia This version has deep red coloring with a yellow starburst in the center. Pink Sky Petunia 'Pink Sky' petunia has hot pink blooms. Night Sky Petunia Companion Plants Shasta Daisy All types of shasta daisies produce white flowers in various degrees of doubleness and size. The sturdy stems and long vase life make the flowers suitable for cutting. Zones 5-8 Daylily Daylily blooms in yellows, oranges, reds, pinks, purples, whites, and peaches, with many different shades and tints. There are many types, including the long, slender petals of spider-type daylilies and daylilies with ruffled double flowers. Some are scented. Zones 3-10 Coneflower Coneflower blooms are usually made up of a brownish-orange central "cone" and a ring of long, slender petals radiating out from it. It's native to grass prairies. Zones 3-9 Frequently Asked Questions Why does my Night Sky petunia have wilted leaves? Your plants are either getting too much water or too little. Check the soil before watering to make sure it's dry enough and needs moisture. Why is my Night Sky petunia completely purple? The pattern on each Night Sky flower can change with the temperature, so your blossoms might transform as the growing season progresses. In general, cooler temperatures yield more white spots, and warmer temperatures intensify the purple color. Usually, you'll see galaxy flowers swirled with the most "stars" in fall as the weather begins cooling down. Should I use epsom salts on my Night Sky petunias? While there's no proof and experts are skeptical, many gardeners believe adding epsom salts to these plants can help them grow and produce more blooms. Was this page helpful? Thanks for your feedback! Tell us why! Other Submit