The Diablo Ninebark tree is also known by its botanical name of Physocarpus opulifolius ‘monlo’ or the Eastern or Common Ninebark. It is a deciduous flowering small ornamental tree that delights gardeners and landscape designers with its clusters of pale pink or white blossoms and brilliant, changeable fall foliage. Learn from experts how to plant and care for the Diablo Ninebark tree in your own home garden or landscape setting.
This tiny shade tree rarely exceeds heights of eight to ten feet, even at maturity, making it useful as a shrub or hedge, as well as a small decorative tree. The Diablo Ninebark tree will quickly reach its mature height, averaging between one and three feet in growth annually. Its unique bark peels, or exfoliates, lending extra visual interest to this already stunning small tree. The Diablo Ninebark tree will grow well in USDA Plant Hardiness Zones 3 through 7, and as a native of the United States, readily adapts to a variety of growing conditions in the Zones for which it is suited.
The Diablo Ninebark tree is an amenable tree and can tolerate a variety of soil conditions, but ideally it prefers moist soil with excellent drainage. It will display the most brilliant foliage and decorative flowers when offered full to partial sunlight. It can tolerate urban as well as rural conditions, including exposure to pollution or environmental toxins, making it a favorite for inner city plantings. With proper planting and care, the Diablo Ninebark tree can live for three decades or longer. It is best to plant the Diablo Ninebark in the spring or fall seasons.
To begin, dig a hole that is as deep as the rootball and two to three times as wide. Remove and work through the soil to remove soil clumps or rocks, then add nourishment in the form of organic matter and compost. Remove any packing material covering the rootball, and gently free the roots and spread them out from the rootball. Place the rootball gently in the hole and backfill the hole with the amended soil. Water the new rootball generously, then allow the soil to drain. If planting the Diablo Ninebark tree in a row or formation, be sure to leave three to five feet of space between each new rootball to allow adequate space as trees begin to grow. Place a protective layer of mulch across the topsoil between plantings, taking care not to allow the mulch to touch the new trunks to avoid crown rot.
The Diablo Ninebark tree will require frequent watering as it grows, and occasional pruning and trimming to remove damaged foliage or provide shaping. Pruning and trimming can be done anytime the tree requires it. The Diablo Ninebark will produce flowers in early to late summer and interesting red seed capsules in fall. The Diablo Ninebark is remarkably disease and pest resistant, even when it comes to aphids, but the tree can be susceptible to visiting deer.