Diablo Ninebark is a deciduous shrub that looks beautiful all year round. With its bold flowers, purple leaves, textured bark, and ability to reach up to 10 feet in width and height, it’s a statement shrub that will rejuvenate any garden.
Diablo Ninebark grows fairly easily, as long as you ensure it has enough space and gets watered regularly.
With this in mind, let’s explore everything you need to know about growing an eye-catching Diablo Ninebark on your property. We’ll explore this shrub’s history, growing tips, and how to keep it healthy.
Diablo Ninebark is part of the Rosaceae (rose) family. Diablo Ninebark got its name “Diablo,” which means devil in Spanish, because of its dark leaves. “Ninebark” refers to its peeling bark that displays different shades of brown.
Its genus name, Physocarpus opulifolius, has Greek origins. “Physa” means bladder and “Karpos” means fruit, so this name refers to the plant’s dry fruits. The shrub’s fruits are actually red seeds that appear at the branch tips after the tree has bloomed.
Ninebark is native to the eastern part of the U.S. Native Americans used an extract from the bark for various purposes, such as analgesics, pain relievers, and even laxatives, although in extreme doses, this substance can be toxic.
Diablo Ninebark grows best in U.S. hardiness zones 3–7. These zones are susceptible to low temperatures and a Diablo Ninebark grows easily in cold temperatures.
However, it is quite adaptable to different conditions. It flowers in full to partial sun in the North but can grow in partial shade conditions if required.
How and Where to Grow
Since the Diablo Ninebark can grow up to 10 feet tall, with a spread of approximately eight feet, you’ll need to ensure you have enough space in your garden for it. It works beautifully in a sparse garden as it’s highly eye-catching.
It also attracts birds and butterflies, which adds to its charm as it brings more life to your garden.
Besides the tree’s ample height and width, Diablo Ninebark blooms pink or white flowers that are about an inch or two in diameter. Its leaves are usually about four inches long.
Since this shrub is tall and wide, it’s perfect for use as a hedge. It provides greater privacy in your garden. Best of all, Ninebark shrubs grow really quickly. They reach their full size within just a year, so they’re ideal for when you want to rejuvenate your garden within a short time span.
Diablo Ninebark prefers soil that’s well-drained. You should keep it evenly moist. However, it’s quite a flexible plant as it can tolerate other soil conditions. Whether you have clay soil, shallow rocky soil, or dry soil, your Diablo Ninebark will be able to grow in it.
When it comes to soil pH, Diablo Ninebark likes neutral soil. However, it can also grow in slightly acidic soil conditions.
Light, Water, and Fertilizer
Diablo Ninebark thrives in partial to full sun. However, if your garden experiences a bit of shade, that shouldn’t be a problem for this low-maintenance plant.
That said, make sure that you give your plant at least six hours of sun per day. This ensures that its beautiful white flowers bloom in the spring.
Water your young Diablo Ninebark once or twice a week. If it’s really hot, you will have to water it every day. When these plants are mature, they don’t require much watering. Only water them when there’s less than an inch of rain every week.
Fertilizer should be given to the shrubs every three weeks from April to August. You can do this with a slow-release, granular fertilizer. This fertilizer slowly releases nutrients into the soil for the plant to absorb, and since it doesn’t enter the soil too quickly, it prevents fertilizer burn.
Liquid fertilizer should be avoided because this will give the plant too much nitrogen. Choose a balanced 10-10-10 fertilizer so you feed your plant all the essential nutrients it requires.
You can propagate your Diablo Ninebark from cuttings or plant its seeds. Make sure you do this in the springtime.
Mix together peat, sand, perlite, and pine bark in a container and add water to it so that it’s moist. This blend will ensure good drainage for the pots. Cover the seeds lightly with the mixture and water the top with a misting bottle.
You should keep the pots outside in a sheltered area where the temperatures remain above 50 degrees Fahrenheit. The seeds will take a few weeks to germinate, so you should keep the soil moist until this happens.
Since these plants can grow really tall and large, if you want to store them in pots, you should opt for a dwarf version of a Ninebark shrub. These can grow to about three or four feet in height.
Choose a large container that’s approximately 20 feet wide and deep to give its fibrous roots enough room to grow.
Water the Ninebark shrub weekly. It might require a bit of pruning to encourage its growth in a pot. However, don’t give it too much water. You should only water the plant when its soil feels dry. To prevent overwatering, make sure that the pot or container has drainage holes.
Keep the pot in an area of the home that gets enough sun as this will keep it looking healthy and encourage its flowers to bloom.
You should prune your Diablo Ninebark regularly but minimally, so you can maintain its shape. Remove damaged branches early in the spring as this will improve the shrub’s air circulation. It’s not necessary to prune the plants back to the ground every few years to rejuvenate them.
If you need to remove more branches, you should do this late in the winter with the use of a pruning saw.
Some of the best companion plants for Diablo Ninebark include dogwood trees, which require the same hardiness Zone, and daylilies, which tolerate various light conditions while looking great when placed around the edges of a Ninebark. These have beautiful bright colors, such as red and yellow, that provide a beautiful contrast with Ninebark’s blooms.
Make sure you avoid keeping your Diablo Ninebark in very hot or humid conditions, as this increases the chance that your plant will get a fungal disease. The best temperature for this plant is approximately -40 to -30 degrees Fahrenheit.
Although Ninebark can tolerate a variety of climates and temperatures, it will fare best when grown in a cool and cold environment. Here is a rundown of other diseases that can affect your Diablo Ninebark, and how to treat them.
Powdery mildew is a fungal disease. It shows up on plants or shrubs in the form of a powdery white coating on leaves, yellowing or dry leaves, or disfigured leaves or buds.
You can prevent powdery mildew from affecting your Diablo Ninebark by keeping it in a sunny area of the garden as this fungus thrives in shady, damp areas.
To remove powdery mildew, there are some homemade recipes that you can try. One is the use of baking soda. Simply sprinkle a teaspoon of baking soda into one quart of water, and mix it well. Spray plants with it to kill any fungus.
You should also remove any affected stems or leaves and throw them away. This will prevent the fungal spores from spreading to other parts of the plant, or nearby plants.
Leaf spot disease can weaken shrubs and trees because it disrupts photosynthesis. It’s caused by a fungus, bacteria, or other pathogens. It shows up on leaves in the form of brown spots that spread quickly to other leaves.
You can prevent leaf spot by not overcrowding your shrubs, pruning your shrubs to increase air circulation, and not splashing water on the leaves of the plants when watering them.
To treat leaf spot, prune the affected leaves and use a fungicide or neem oil to treat them.
This is a disease caused by bacteria. It kills flowers and can cause branches to die back. In extreme cases, fire blight can cause trees to die. Some symptoms include:
- Shriveled flowers
- Young leaves turning gray-green
- Cracked or dark bark
- Droplets of beige, sticky liquid along infected branches
There aren’t many pests that attack Diablo Ninebark. However, one that does is aphids.
Aphids are small insects that suck liquids out of plants. They can damage plants in this way and since they multiply quickly, you should eliminate them as quickly as possible.
You can tell that aphids are attacking your plant if you notice that it’s becoming disfigured and its leaves are becoming yellow and/or dying off. The appearance of honeydew on the leaves, which presents with a black mold fungus, is also a telltale sign of aphids.
This honeydew is produced when aphids pierce the shrub’s plant tissue ducts to reach the plant’s sap. The sap gets pulled into the aphid’s body before being released as excrement.
To remove aphids, you have to spray the shrub with water as this will dislodge the aphids. However, sometimes you need something stronger, such as neem oil or insecticidal soaps.
If you’re planting a beautiful Diablo Ninebark in your garden, you’ll love that it’s a low-maintenance shrub. However, there are some crucial things to know about looking after it and keeping it thriving.
In this article, we’ve provided you with everything you need to know to ensure your Diablo Ninebark remains healthy and blooms beautifully.