How To Grow And Care For Black Dahlia Flower On Your Own

black dahlia flower

With over 50,000 varieties of dahlia flowers, it might seem impossible to stand out from the crowd, but Black Dahlia flowers do so with alluring ease. These enchanting flowers may appear challenging to grow when the reality is, they are very uncomplicated.

How to Identify Black Dahlia Flower

This type of dahlia flower is defined by dark and moody burgundy hues that allow this flower to express and symbolize strong emotions. Its petals are firm and spoon-shaped. They are placed in a circular formation that creates a dainty rosette.

How to Grow Black Dahlia Flower from Seed

Dahlia flowers can be grown from seeds purchased from a reputable seller or by harvesting dahlia seeds directly from your own flowers. The steps for growing a black dahlia flower from seed are simple and straightforward. The steps are:

  1. Fill a seed starter tray with a soilless seed starting mix
  2. Place the seeds into the seed mix and cover them lightly with the mix (seeds should be spaced around 3 centimeters apart)
  3. Water the seeds so that the seed mix is moist, but not soggy
  4. Set the seed tray in a place that is warm (70 degrees Fahrenheit and above)
  5. Keep the seed mix moist
  6. Look for evidence of germination between one and two weeks after sowing the seeds
  7. Transfer the sprouts into individual pots once their leaves are large enough that they touch one another (3-inch planting containers are recommended)
  8. Allow the sprouts time to harden before moving them outdoors
  9. Move the new plants outdoors after the chance of frost has passed

How to Harvest Black Dahlia Flower Seeds for Propagation

The steps for harvesting black dahlia seeds are as follows:

  1. Pick pods that are light tan to green in color and connected to flowers that have dropped their ray petals
  2. Allow the pod to dry
  3. Remove the seeds from the pod
  4. Allow the seeds to dry
  5. Store the seeds in a glass jar or paper envelop that is kept in a cool, dry place that has little or no sunlight

Note: Propagation of dahlia flowers via seed does not guarantee that the plant grown from the seed will be an accurate replica of its parent flower. To grow an accurate replica of a particular dahlia flower, it is necessary to propagate a new plant via bulbs or tubers.

How to Propagate Black Dahlia Flower

Learning how to propagate a black dahlia flower from a tuber may take some time, but it is absolutely necessary in order to guarantee a healthy plant that has the features of a black dahlia. The steps for this method of propagation are:

  1. Select a tuber that is firm and does not show any signs of mold, rot, or wrinkles (look for eye buds and green growth on them)
  2. Prepare the garden bed by setting up support stakes in the ground
  3. Dig 6 to 8-inch deep holes that are spaced two feet apart
  4. Set one tuber on its side into each hole
  5. Cover the hole with soil
  6. Cover the soil with mulch

When to Plant Black Dahlia Flower

Whether you are growing a black dahlia flower from seed or from a tuber, it should be planted outdoors after the last chance of frost has passed and soil temperatures stay above 60 degrees Fahrenheit. They can be started indoors and transferred outside once the weather is warm.

Best Black Dahlia Flower Fertilizer

Black Dahlia Flowers can benefit from a feeding every three to four weeks once they have sprouted. They should be fed with a 10-10-10 fertilizer.

Black Dahlia Flower Soil Requirements

These flowers should be planted in soil that is well-draining since dahlias do not grow well in soggy soil. Miracle-Gro Garden Soil for Flowers is an excellent choice to use when planting dahlias. It is also necessary to plant these flowers in soil that has a pH level ranging between 6.5 and 7.0.

Black Dahlia Flower Light Requirements

All types of dahlia flowers require 6 to 8 hours of full sunlight each day. It is best to provide this to them in the morning and then keep them slightly shaded during the afternoon.

Black Dahlia Flower Water Requirements

Do not bother watering tubers since this actually harms them and hinders their growth. Once sprouts appear above ground, they will need deep watering (30 minutes) 2 or 3 times each week. They may require more if you live in a hot and dry climate.

Best Black Dahlia Flower Companion Plantings

Garden companion plantings are more than just considering which flowers will look pretty next to each other, it is also a chance to provide beneficial nutrients and a natural line of protection for your beloved plants. When you set your black dahlia flowers in a garden bed, consider planting the following as their neighbors since they will help your dahlias be the healthiest and best-looking flowers possible.

  • Anise is an herb that will provide your dahlias protection from aphids by attracting their natural predator, wasps.
  • Italian Oregano is another herb that is a deterrent to many sap-sucking insects that would enjoy munching on your dahlias.
  • Monarda, which is also called Bee Balm attracts bees that will pollinate the flowers.
  • Roses and peonies are both traditional flowers in perennial gardens and they look lovely next to dahlias. If you are trying to create a vibrantly colored garden, then these flowers are ideal companions.

Black Dahlia Flower Treatments and Maintenance

These flowers are not extremely attractive to pests or diseases, but they do have a few common problems that they do face. It is best to learn in advance what problems these flowers face, how to identify these problems, how to prevent these problems, and how to treat them if these problems arise. Here are the most common issues faced by dahlias and how to deal with them:


This insect infestation looks like tiny globular bugs clustered onto leaves and stems.  Symptoms of this type of infestation are:

  • Leaves that are yellowing
  • Leaves that are growing crooked
  • Leaves that have had their growth stunted
  • Black and sticky residue on the plant
  • Honeydew trails on the plant

The most effective way to deal with an infestation of aphids is to introduce predatory insects into your garden and naturally get rid of the ants.  Ants feed on aphids and for this reason, they will fight to protect aphids from predatory insects such as ladybugs and lacewings.  If you can introduce predatory insects into your garden while removing the ants, you may succeed in ridding your plants of aphids as well.

The best way to bring these beneficial bugs into your garden is to attract them to your garden by planting some of their favorite plants.  These include:

  • Dill
  • Fennel
  • Mint
  • Yarrow

Botrytis Blight

Evidence of this is rotten buds and a powdery substance that covers the plant. To deal with this issue, infected parts should be removed and destroyed.


This is a caterpillar that will eat straight through a plant stem if not stopped.  The best ways to deal with them are:

  • Use compost when preparing your garden bed for planting
  • Remove weeds from around the plants
  • Maintain a 3-foot circle of dry soil around each plant, if possible
  • Remove any larvae from the plant or garden
  • Install a cutworm collar around the plant
  • Use a pesticide
  • Use a slug bait

Gray 3Mold

This fungal infection shows up on plants as a grayish-brown coating that causes leaves and stems to wilt. To deal with this type of infestation, apply a fungicide to the plant and consider these preventative measures:

  • Remove stems, leaves, and fruit that have been infected
  • Remove debris from around the plant
  • Only water the soil of the plant rather than its leaves


These pesky insects are frequent garden invaders. They can cause Aster yellows in dahlias which will eventually kill the plant. To deal with leafhoppers, it is recommended that a horticultural soap be sprayed onto the plants.

Mosaic Virus

Evidence of this is stunted growth in the plant and leaves that grow disfigured. There is no cure for this virus and it can spread to other plants, any infected plants should be promptly be destroyed.

Powdery Mildew

This is a mold infestation that looks like a white powder covering stems.  To deal with this type of infestation, apply a fungicide to the plant and keep debris away from the plant.

Snails and Slugs

These pests can be treated by any of the following methods:

  1. A beer trap.
  2. A copper screen barrier.
  3. Crushed eggshells around the plant.
  4. Poison bait.

Spider Mites

Symptoms of this type of insect infestation are:

  • Leaves that have yellow, white, or tan spots on them
  • Leaves that have tiny red or white spots that move around on them
  • Leaves that have a cotton-like webbing covering their undersides

The most effective and natural way to deal with an infestation of spider mites is to introduce predatory insects into your garden.  Predatory insects include ladybugs and parasitic mites.  Other ways to deal with this type of infestation are to apply insecticidal oil or neem oil to the plants.

Stem Rot

Evidence of this is a white ring around the stem of the flower. Since it is caused by over-watering it can be prevented by watering the plant properly.


This type of insect can damage plants by laying eggs in new blooms. To deal with this infestation, apply an insecticide to the plant.

Where to Purchase Black Dahlia Flower Online

Dahlias are delicate flowers and this should be taken into consideration when purchasing them online. If you need a flowering dahlia, it may be best to call a florist rather than purchase them online because they will have to be shipped to you and they don’t ship very well. However, if you are interested in the convenience of a beautiful flower being shipped directly to your doorstep, proceed with caution, but consider purchasing from these online shops:

  • Black Dahlia Inc.
  • Fifty Flowers
  • Flower Moxie

The best way to purchase Black Dahlia Flowers online is either in seed or tuber form. If you are interested in finding seeds or tubers to grow in your garden, consider purchasing from these online shops.


Note: Keep in mind that dahlia seeds are not guaranteed to look exactly like their parent plant when they are fully grown.



Question: Which USDA Hardiness Zones Can Black Dahlia Flowers be Planted In?

Answer: These flowers can be left outside in the winter in zones 8 through 11. When grown in zones 2 through 7, the tubers should either be brought in for the winter or they should be to treated as an annual plant that will need to be replanted each year.

Question: How Should Tubers be Removed and Stored during the Winter?

Answer: Tubers should be removed from the garden bed before any hard frosts but after the plant has turned brown and is beginning to die back. The steps for digging them up are as follows:
Remove any remaining foliage and cut the flower stems down to 2 inches.
Use a digging utensil to carefully remove the tuber from the ground without cutting it.
Remove the tuber from the ground and dust off any excess soil from it.
To store the tuber throughout the winter, follow these steps:
Set the tuber in soft but loose packing material (dry sand is an excellent option).
Place the packaged tuber in a spot that is cool (45 degrees Fahrenheit) and ventilated.
Remove and plant the tuber after the final frost in the spring.

Question: Are Black Dahlia Flowers Toxic?

Answer: This is a very interesting flower because humans can eat all parts of this flower but pets cannot. This is a toxic plant that your beloved pet should not consume. If they do, they may experience some stomach pain and skin issues. It should not be extreme, but you should keep animals from munching on them.

In Conclusion

Black Dahlia Flowers are one of nature’s extremes. They are beautiful while they are also melancholy. They are delicate while they are also forceful. If you ever wanted a flower that expressed so much in such a small package, then look no further than this dahlia. It is guaranteed to bring your garden drama, contemplation, and stunning looks.

Research Citations

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top