Superb Shrubs: Ninebarks

Ninebarks have long been one of my favorite shrubs and I know they will become yours too. They come in a wide array of colors and sizes, and there is one for nearly every corner of your garden.

In the past decade there has been a lot of breeding and releases of new ninebarks to the garden, and a lot of work done to get smaller smaller sized plants that require less pruning. If left to themselves, many of the older ninebarks will grow 12 feet tall and wide. 

Are ninebarks native to North America?

Ninebark Amber Jubilee new growth

Ninebark (Physocarpos opulifolius) is native to the Central and Eastern United States. It can be found growing along streambanks, rocky outcroppings, and woodland edges in full to part sun. Besides its showy white to pink flowers, it has excellent peeling bark. It is adaptable to a wide range of soils and sites. If left un-pruned, they grow vase shaped, much like their cousin, the Vanhoutte spirea. 

Ninebark Little Devil blooming

When is the best time to prune ninebarks?

Ninebarks can be sheared into shapes, cut into hedges, used in mass plantings, or as a focal point in the landscape. They are best sheared or pruned in June or September, but can be lightly pruned anytime from May to October with no ill effects.

What are some of the best cultivars of ninebarks?

‘Amber Jubilee’ is a dark green leafed form with orange-yellow-gold new growth that grows 6 feet tall and wide. I have this variety in my entry garden and I love the new foliage as it emerges, golden amber to burnished bronze. So far, in part shade it has not reached its full height potential, staying around 5 feet tall and wide.

‘Coppertina’ is known for orange-copper new growth that turns maroon in summer and grows 8 feet tall and wide. I just planted this one into a full sun location in my islands out back. I am looking forward to its color among my Siberian iris trials.

‘Lemon Candy’ is a recent introduction with chartreuse-green leaves and white flowers, growing 6 feet tall and wide. I am planning to add this introduction into my shrub border this year, along with other gold leafed plants such as Aralia ‘Sun King’, Elderberry ‘Lemony Lace’, and Arborvitae ‘Fluffy‘.

‘Little Devil’ is a commonly used variety, with dark, maroon leaves, growing 5 feet tall and wide. This my favorite variety. The leaves are much smaller than other cultivars and it works well in full sun or part shade. I have one beside my water fountain and the arching habit is very showy.

Can I cut ninebarks to the ground?

Older ninebarks should be rejuvenated by cutting to the ground (6 to 12 inches) in early March. I try to cut them back this hard every 3 years to encourage new growth. They can be pruned any time of the year without worry about sunscald or damage.

These ninebark aphids can be removed from the plant by pruning

Can ninebarks be trained into tree shapes?

Some ninebark cultivars are set on standards in the form of “lollipop” trees. This means that the shrub is grafted onto a single branch that has been grown into a single leader. While these “trees” are very pretty, they need protection from strong winds.

What pest problems do ninebarks have?

Ninebark aphids can be a problem occasionally but are easy to manage. They are usually found along the tips of the growing branches, and can be pruned out without much damage to the shape of the shrub. Sprays are not recommended for this pest.

On older varieties such as ‘Diablo’ I have seen infestations of powdery mildew. This fungal disease is caused primarily by wet conditions on the leaf surfaces, such as when a sprinkler sprays water on the plant. Most of the mildew I have seen was where lawn sprinklers were incorrectly set to hit the flower beds.

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