How to Grow and Care for Galaxy Flowers

Jump to: Fast Facts | How to Grow | How to Prune | How to Repot | How to Propagate | Common Issues | Our Recommendation | FAQ

Galaxy flowers bring the dazzling beauty of the starry night sky into your home or garden. These deep purple flowers are sprinkled with brilliant white dots, which earned them the nickname night sky flowers. Gardeners grow these delicate but hardy plants indoors and outdoors across the country. They are easy to start from flower seeds, and they flourish with moderate levels of care and attention.

In fact, the galaxy flower won the prestigious FleuroStar Contest in 2015/2016. Held annually in the Netherlands and Germany, this contest identifies the “winner with the wow factor.” More than one-third of the contest’s 30 judges awarded the petunia night sky the maximum number of points for commercial potential and point-of-sale attractiveness. Today, its unique patterns make this flower popular with botanists and flower lovers around the world.

 

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Fast Facts on Galaxy Flowers

The galaxy flower is a type of petunia—a genus of more than 20 species of flowering perennials that is related to the potato, eggplant, and tobacco plant. Though petunias are native to South America, Italian botanist Antonella Capo first bred the galaxy flower in 2012.

Common name	Night Sky Petunia, Starry Sky Petunia
Plant family	Solanaceae
Native climate	None
Light level	Full, direct sunlight for five to six hours daily
Average mature height	14 to 16 inches tall
Soil type	Well-drained, neutral or slightly acidic
Frequency of watering	Once weekly
Toxicity	Nontoxic to humans and animals
Ideal humidity level	Average

Formally known as the petunia night sky, the galaxy flower grows best in warm, humid climates. The secret to growing petunias is a mix of full sun and well-drained soil. These flowers thrive in five to six hours of direct sunlight per day. You don’t necessarily want your plants to get too hot, however.

Temperature changes affect the white-to-purple ratio on the flowers. In colder temperatures, galaxy flowers show more white, and in hotter environments, they emphasize purple. The white dots will disappear entirely if the weather stays hot enough for long enough. 

Galaxy petunias enjoy a robust growing season that can begin in the spring and extend into the fall. When fully grown, these plants can be 14 inches tall.

 

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How to Grow Galaxy Flowers Indoors

Galaxy flowers feature some of the most beautiful blossoms in the world. They’re also relatively easy to grow, as long as you have the right conditions. To care for your galaxy flowers, water them regularly and fertilize them monthly. Pruning the plants back after they bloom will encourage new growth.

Fertilizing

Galaxy flowers need regular fertilization. Gardeners can use a balanced fertilizer at 150 to 250 parts per million (ppm) nitrogen supplemented with iron and minor elements in a constant feed. Your local garden supply shop can help you find and mix the right fertilizer.

If the pH balance in your soil is too acidic (yellowing leaves are a telltale sign of this problem), irrigate your plant with high-alkaline water.

Lighting

Galaxy flowers need a lot of light. Optimally, these plants would get five to six hours of full sun daily. If they have insufficient sunlight, galaxy flowers fail to thrive—their blossoms thin out, and they show signs of stem stretch.

For best results, place your galaxy flowers near a window with plenty of natural light, or you can DIY your light source by investing in some plant lights. LED lights and other artificial light sources can encourage your petunias to blossom, but gardeners should keep light intensity to 50,000 to 80,000 lux.

Soil

Like other petunias, galaxy flowers flourish best in rich, loamy soil filled with organic matter. However, they will grow in nearly any potting mix you put them in. Ask at your local garden center or search on Amazon for a product you like. 

Whatever potting mix you choose, create adequate drainage holes for your plants. If petunias sit in water too long, they can develop root rot. This condition cannot be reversed; if not addressed, it will destroy your plant.

Temperature

Galaxy flowers like to grow in warm temperatures. The temperature should run between 55 degrees Fahrenheit and 75 degrees Fahrenheit during the day and 55 degrees Fahrenheit to 65 degrees Fahrenheit at night. 

Temperatures dramatically affect the striking colors and patterns that make galaxy flowers unique: the colder the environment, the more white spots on the petal. The deep purple color tends to take over as the temperature warms up. 

When the weather gets hot enough, the flower’s distinctive white speckles may disappear altogether. Not to worry, though; the dark purple petunias are still beautiful in your garden.

Watering

Watering is a bit delicate with these plants. The soil should be moist but not too wet. Make sure to water your galaxy flowers frequently, but do not let them sit in water, or they can develop root rot.

 

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How to Prune Galaxy Flowers

Pruning your galaxy flowers is a crucial step in keeping them healthy and ensuring they bloom beautifully. It’s best to prune your plants once in mid-July, again in mid-August, and finally in mid-September. Don’t prune more than one-third of the plant’s stems at any single pruning.

To prune, cut off branches that are browning or dead, as well as any stems with flowers. If you want to encourage new growth, remove any buds inside of the flower that haven’t yet opened. These can be snipped with scissors or pulled off gently with your fingers.

 

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How to Repot Galaxy Flowers

Galaxy flowers enjoy a full growing season, and before it’s over, they may need a bigger pot to grow in. To repot your galaxy flowers, start by picking a pot one size larger than its current pot. Then, fill the new pot with a fresh, disease-free, and loosely packed potting mix. 

Gently remove your plant from its current pot, careful not to damage the roots. Finally, place the plant in the new pot, and fill in around it with more potting mix.

 

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How to Propagate Galaxy Flowers

While galaxy petunias are technically perennials, they rarely survive the cold weather. Consequently, most bedding plants are produced annually from flower seeds. 

Fortunately, galaxy flowers are relatively easy to propagate. Follow these four easy steps: 

1. Take a cutting from an existing plant. 
2. Place it in water or moist soil. 
3. Keep the cutting in a warm, sunny spot and wait for new growth to appear. 
4. Once the plant has rooted, transplant it into a pot or garden bed. 

To care for your galaxy flowers, plant them in well-drained soil and water them regularly.

 

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Common Issues with Galaxy Flowers

Although galaxy flowers are uncommonly easy to grow in baskets, flower beds, or gardens, they are susceptible to various conditions and adverse growth environments.

Diseases

Like most other plants, galaxy flowers are susceptible to diseases. Botrytis, Rhizoctonia, and Pythium are three diseases commonly found in galaxy flowers. You can usually avoid Botrytis by allowing your soil to dry between waterings. Improving drainage and aeration can prevent Rhizoctonia. You probably need to invest in a fungicide if your plant gets Pythium. 

Inadequate Sunlight

Galaxy flowers need a lot of sunlight. Without enough of it, the flowers will not be able to grow properly, and the plant quality will be reduced. Low light levels can result in delayed flowering, excessive vegetation growth, or stretched plants. 

Overgrowth

Excessive vegetation growth occurs when your plant has many leaves and few blossoms. Possible reasons for overgrowth include over-fertilization, high ammonia concentration in the soil, low light levels, overwatering, and wet media.

Tightly Packed Soil

To grow galaxy flowers, the soil needs to be well-drained. If the soil is too dense, the water will not reach the roots, and the flowers will not be able to get the nutrients they need. 

You can tell if your soil is tightly packed by noticing how long the dirt takes to absorb water. If you notice water pooling on top, your soil is too tight. You might also observe some of your plant’s leaves starting to yellow from lack of water and nutrient absorption. 

Adding earthworms or organic materials, such as peat moss, can help loosen up your soil.

Pests

Aphids, thrips, fungus gnats, whitefly, and leafminers are all common pests that can attack galaxy flowers. A professional pest control service can help prevent bug infestations and improve plant health.

 

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Our Recommendation

Galaxy flowers add an aesthetic flair that’s almost out of this world. They’re unique, fun plants that require only moderate care if planted in bright, sunny locations. Galaxy flowers can add cosmic color to your flower beds or hanging baskets, or they can make unique gift ideas for Mother’s Day or another holiday. 

You can propagate a cutting from a friend’s plant, start your galaxy flowers from seed, or buy a young plant at the garden shop. If you are seeking a full-grown galaxy flower, consider purchasing one from an Etsy shop for a memorable Valentine’s Day gift or another flower gift.

 

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