Ninebark Standard 'Diabolo®' (Physocarpus opulifolius)
Features
This lovely tree form is perfect for bringing Diabolo® up to eye level where it’s burgundy foliage and white flowers can be better appreciated. An excellent selection for creating a focal point in a perennial border or planted as a pair on either side of a doorway. The size is right for small-space gardens or used in a large planter for a deck, patio or poolside. Also known as ‘Monlo’.
Uses
An excellent specimen, foundation, or border plant. Nice for larger patio containers.
Plant Feed
Fertilize regularly for best display.
Watering
Keep well-watered.
Soil
Well-drained, slightly alkaline soil.
Basic Care Summary
For best results, plant in slightly alkaline, fertile but well-drained soil. Keep soil moist, watering freely in dry weather. Breaks dormancy late so be patient for spring growth. Remove faded flowers for best display.
Planting Instructions
Choose a location that will allow roots to spread and branches to grow freely. Space plants far enough from building foundations, walls, and decks so that the growing foliage won’t crowd the structure.
If planting in the ground:
To prepare the planting area dig a hole as deep as the root ball and three times as wide. After removing the soil, mix it with some compost or peat moss. This enriches the soil and loosens the existing dirt so that new roots can spread easily.
Remove the plant from its nursery container and set the plant in the hole.
Return the soil to the planting area packing it firmly around the root ball. Fill the hole until the soil line is just at the base of the plant, where the roots begin to flare out from the main stem.
Water the plant well then add a 2” (5cm) layer of mulch, such as shredded bark, around the planting area. Keep the mulch at least 4” (10cm) away from the trunk of the plant as this can keep the bark too moist and cause it to decay.
If planting in a patio planter or other container:
Start with a good quality, commercial potting soil. These are usually lighter in weight than topsoil, sterile and pest-free. Many are available with a mild starter fertilizer in the mix.
Select a container with a drainage hole or be prepared to drill holes for drainage if there are none.
Prepare the container by filling with potting soil up to 2” (5cm) from the rim of the planter leaving some space in the middle for placing the plant. Remove the plant from its nursery pot.
Insert the plant into the hole and press soil firmly around the roots. Add soil if necessary to cover the root ball. Water thoroughly to settle the soil and give plants a good start.
Plan ahead for vining plants that might require a trellis or support cage. It’s best to install supports at planting time, before the foliage gets bushy.
Watering Instructions
Depending on rainfall, new plants need to be watered weekly through the first growing season. During hot spells thoroughly soaking the ground up to 8” (20 cm) every few days is better than watering a little bit daily.
Plants in containers can dry out quickly, depending on the weather, and may need water more frequently than plants in the garden bed. Check the soil moisture with your finger. If the top 2-4” (5-10cm) of soil is dry, or plants are wilted, it is time to water.
Apply water at the soil level if possible to avoid wetting the foliage. Water the entire soil area until water runs out the base of the pot. This indicates that the soil is thoroughly wet.
Deep watering encourages roots to grow further into the ground resulting in a sturdier plant with more drought tolerance.
To check for soil moisture use your finger or a hand trowel to dig a small hole and examine the soil. If the first 2-4” (5-10cm) of soil is dry, it is time to water.
Pruning Instructions
Pruning may be needed to remove dead branches, encourage bushier growth, promote more flowers, or maintain a specific size or shape.
Most container plants can be pruned freely to maintain the desired size and shape. Keeping the foliage trimmed also keeps the plants looking neat and tidy, encourages the plant to develop more side-shoots and flowers, and reduces the demand for the plant to develop a larger root system. This is important since the roots are in a confined space.
Many shrubs can be regularly sheared to keep them shaped as a hedge, edging or formal foundation planting.
When pruning to control a plant’s size or shape, cuts should be made just above a leaf bud and at a slight angle. This bud will be where the new growth sprouts.
Remove old flowers to keep plant looking healthy and prevent seed production that drains the plant’s energy at the expense of forming new flowers.
Always use sharp, clean tools when pruning. There are many tools available depending on the job. Hand shears, pruners, and loppers are ideal for most shrubs. Pole pruners and tree saws are better for large, mature shrubs or trees. If a tree is so large that it can’t be safely pruned with a pole pruner, it is best to call in a professional tree service.
Fertilizing Instuctions
Fertilizers are available in many forms: granulated, slow-release, liquid feeds, organic or synthetic. Determine which application method is best for the situation and select a product with a nutritional balance designed to encourage blooming (such as 5-10-5).
Too much fertilizer can damage plants so it’s important to follow the package directions to determine how much, and how often, to feed plants.
Slow-release fertilizers are an especially good, care-free choice for container plants. A single application can often provide plants with the proper level of nutrition all season long.
Plant Details
| Category | Nursery |
| Height Range | 6-8′ |
| Height Metric Range | 1.8-2.4m |
| Space Range | 3-4′ |
| Space Metric Range | 0.9-1.2m |
| Available Colors | white |
| Companion Plants | Cedar, Hydrangea, Daylily |
| Lowest Temperature | -40° to -30°F |
| Lowest Temperature Metric | -40° to -34°C |
| Bloom Time | Midsummer |
| Plant Light | Full Sun |
| Hardiness Zone | 3, 4, 5, 6, 7 |