Skip to content

How to Care for Black Magic Petunia

Black Magic Petunia via Imgur

The Black Magic Petunia is a hybrid flower that blooms the blackest flowers you can find. This hybrid was created in 2013 from another hybrid petunia variety called “Black Magic.”

Many people use this plant to create a dramatic “pop” in their gardens. The deep black flowers and bright green leaves will make any brightly colored flowers stand out! Only in bright direct light can you tell that this is indeed a deep purple and not a true black.


Growing Black Magic Petunia

Black Magic Petunia plants can sometimes be found in local garden centers but are best grown from seeds to ensure enough is produced. The best way to grow these tiny seeds is in a starter tray. Once you plant the seeds in a tray, mist them thoroughly and cover them with clear plastic until they begin to sprout. The clear cover will help create a greenhouse effect, so you won’t have to continually water or worry about the humidity around the seeds.

Once the seeds have sprouted, you can remove the lid but keep them in this tray until they reach several inches high. These plants thrive in warm weather, so they will like a bright warm location away from direct sun to avoid burning. You may have to pull up the smaller plants to avoid overcrowding in the tray. 


Once you are ready to plant, you’ll have to prepare your flower bed or pots first. Because the Black Magic Petunia is still a Petunia, you should remember that it is a trailing and mounding plant that can grow about a foot round and tall. Since they are compact, they are great for hanging baskets, patios, or even houseplants.

black magic petuniaPin
Black Magic Petunia via Imgur


Using good-quality soil is essential to growing thriving plants. Petunias prefer loose well-draining soil. Slightly acidic soil is also necessary for happy plants. 

If you plan on growing Black Magic Petunias in a pot, choose a high-quality mix designed specifically for Petunias. You can also have moss to give your soil great drainage while preventing moisture from staying stagnant in the container, as moss is a water retaining plant. 


Black Magic Petunias are drought-resistant plants, as are other petunia varieties. This makes these plants ideal for most gardens and new gardeners trying to create a beautiful indoor space.

Petunias prefer to be watered about once a week. The best method for watering Petunias is to allow water to flow through the roots slowly. These plants will stunt their growth and grow shallow roots if not watered correctly. 

If you are growing your Petunias in a container instead of in a garden bed, you may need to water them more frequently. It would be best if you gave the soil time to dry slightly between watering, and it should only be watered when the top inch of the solid is dry. Be sure to use containers with drainage holes, as these plants are prone to root rot. 


Petunias prefer bright light. They should be placed somewhere where they will receive about 6 hours of direct sun and 4 hours of indirect sun each day for a total of about 10 hours. To pick the best place for this, you should track where the sun rises and sets on your flower beds. 

If planting indoors, you should try and get your plant in a south-facing window. This ensures your plant will receive the most sun possible since the sun will arch from East to West across the sky. You can also place your plant in a location of insect sun but be sure your plant receives at minimum 8 hours of sun, or you may have to substitute with artificial light.

Without enough sun, these plants will not produce as many beautiful flowers. Petunias will also become spindly and weak if their sunlight needs are unmet. Shade also increases the risk of many fungal diseases common in Petunias. 

For the most part, these plants can not receive too much sun. Petunias will soak up as much sun as possible and will try to grow in the sun’s direction if their needs are unmet.

Black Magic Petunia via Imgur


Even though these plants love the sun and do well in summer, they can receive too much heat. Petunias can be damaged in temperatures over 90℉ (32℃). Even indoor plants can be damaged if left in hot, stuffy rooms.

 You should insulate black Magic Petunias as well as any other variety with a thick layer of mulch to hold in moisture and protect the shallow roots. Watering frequency should be increased during times of extreme heat early in the morning or late in the afternoon to avoid sunburn by wet leaves.


Encouraging Petunias to grow by offering regular fertilization ensures you get the best output from your plants. Choosing the right fertilizer for your Black Magic Petunia is key to avoiding fertilization burns. Generally, the best type of fertilizer is one with balanced macronutrients; examples are fertilizers with 10/10/10 or 8/8/8.

Slow-release fertilizers are the top choice of botanists for Petunias. This should be applied in the spring to encourage growth and again in early June or late May to encourage blooms. Be sure to follow the directions listed on your fertilizer to avoid burns. 

Indoor plants can be fertilized more often since they won’t receive the natural fertilizers found in your garden beds.


The easiest way to propagate a Black Magic Petunia is by clipping off a stem in the spring. Prepare a small pot with a mixture of perlite and rinsed damp moss for each clipping. You should also have some liquid rooting hormone. Propagation without the rooting hormone is possible, but there is a higher success rate when this is used.

Clip off a stem 3 to 5 inches tall with a good crown of leaves, and avoid selecting one with flowers or signs of disease. Apply the rooting hormone to the clipped end of the stem and plant in the prepared pot, place a plastic bag over the stem, and mist daily. Only add water when the soil fully dries out. After about 3 weeks, you should develop roots and discard any plants without roots after 4 weeks. 

Seeds can also be collected from Black Magic Petunias but tend to be harder to accomplish regrowth. Since this is a hybrid variety, it will likely get a mix of Black Magic and other Petunia varieties from the seeds. You can collect seeds by placing an unopened flower in a plastic bag and gently cutting off the tip to release the seeds. 

Black Magic Petunia via Imgur


If you are growing a plant indoors or in a container, it will likely need repotting at some point. It is best to repot Petunias in the spring because they are just coming out of their dormant season. Repot into a pot 2 or 3 sizes bigger than the previous container. 


To increase the time Petunias will bloom, prune off dead flowers and stems that are more than 8 inches long. Cutting away the long stalks just below the flower will increase flowering. But when should you prune your Petunias?

Around the beginning of July, You should give your Petunias a light prune after its growing season in May and June. This is when you’ll want to cut back about one-third of the plant, focusing on long and scraggly branches.

Again in Mid-August, you should remove anything that looks scraggly or has long branches until the plant has a uniform shape. Like in July, you should trim back no more than one-third of the plant.

Your last pruning will be done in mid-September. Just like the last two pruning, cut back about one-third of the plant and create a uniform shape trimming away scraggy or long limbs.

Throughout the year, you should trim off old and dead flowers just below the bud to encourage new flowers to grow.

How Do You Keep Black Petunias Black?

Petunias that become too hot can change colors or even produce stripes on the flowers. Keeping them at an ideal temperature is the best way to keep Black Magic Petunias their original color.

Annual or Perennial?

Black Magic Petunias require a lot of care but is all that work worth it? Petunias are considered perennials, meaning they will come back each year if the proper steps are taken during the winter months.

Petunias do not tolerate frost, so most will die off in the winter, so they are most commonly sold as annuals meaning they will need to be replanted or regrown from scratch each year. 

It is possible to keep these plants around by insulating them and covering them with plastic or a container to keep the frost from penetrating the roots and killing the plants.

Black Magic Petunia via Imgur


The Black Magic Petunia is a beautiful hybrid petunia that loves sunlight and will produce deep purple flowers that appear black as long as they do not get too hot. They require basic care and watering with a structured pruning schedule. If taken proper care of, these plants can return year after year.

Subscribe To Our Newsletter

Receive a 10% off coupon code to our store.

You have Successfully Subscribed!