When to Prune Henry's Garnet?

Growth

• "Henry's Garnet" sweetspire has an erect growth habit and naturally forms a mounded plant about 3 or 4 feet tall, with a spread that can be up to 6 feet. It has oval, dark green leaves about 4 inches long and produces cylindrical, drooping clusters of white flowers called racemes in May and June that attract clouds of butterflies. The plant's young stems are purplish red, becoming red and eventually green as they mature. Like all cultivars of this plant, "Henry's Garnet" is a slow-growing shrub that adds a foot or less to its height each year.

Timing

• "Henry's Garnet" sweetspire produces flower buds in spring on branches that grew during the previous season, called old wood. Because of this, it's important to prune the plant as soon as flowers fade in early summer, because this gives the plant enough time before winter arrives to produce shoots that support flowering the next season. Pruning the plant in mid to late summer won't injure it, but it interferes with flowering the following spring. Avoid pruning "Henry's Garnet" in fall, because this encourages new growth that can be damaged by winter's cold temperatures.

Pruning

• To keep a "Henry's Garnet" shrub growth under control, cut back secondary branches by about one-third each year, a strategy that encourages new shoots to grow and keeps the plant bushy. Keep the plant erect and narrow in form by pruning back wide-spreading branches at their origins and trimming other branches back at buds that face inward. This encourages new growth toward the plant's center, which minimizes its width. If wind or stormy weather damages or breaks branches in the plant, these can be removed at any time.

Other Needs

• A "Henry's Garnet" sweetspire bush grows in either full sun or partial shade, it but prefers a spot that receives full morning sun that is followed by light shade in the afternoon, especially in areas with strong summer sun. It's adaptable to any type of soil, but prefers a moist area with organically rich soil. You can boost the soil's organic content and increase its fertility by adding compost to the planting site. This plant has a tendency to be invasive, spreading by sending out straight shoots, or suckers, from its roots. To control this, remove new sprouts as they appear at the base of the plant.