The Spiraea x bumalda ‘Goldflame’ is a popular deciduous shrub celebrated for its dynamic, multi-season color changes. New foliage emerges in striking bronze-red or copper tones in spring, maturing to bright yellow-green or gold during summer. Routine structural attention is required to maintain its dense, mounded form and maximize its colorful display. Proper pruning ensures the plant remains vigorous, promotes good air circulation, and encourages a robust show of foliage and rosy-pink summer flowers.
Optimal Time for Maintenance Pruning
The correct time for pruning this shrub is determined by its specific flowering habit: Goldflame Spirea blooms exclusively on new wood, meaning flowers develop on growth produced during the current season. Therefore, annual shaping should occur in late winter or very early spring, just before the buds begin to swell but after the harshest winter weather has passed. Pruning at this dormant stage stimulates a strong flush of new stems, which carry the summer flowers and display the brightest spring foliage color. This directs the plant’s stored energy into new growth, resulting in a more compact and floriferous shrub.
A secondary, lighter pruning can be performed in mid-summer once the first clusters of rosy-pink flowers have faded. This process, known as deadheading, involves removing the spent blooms and lightly shearing the branch tips. Removing fading flowers before they set seed signals the plant to produce new buds, often resulting in a second, smaller flush of blooms later in the season. This mid-season trim is purely for aesthetics and to encourage continued flowering, but it should not be a major size reduction.
Step-by-Step Shaping and Sizing
Routine annual shaping, performed during late winter dormancy, focuses on reducing size and improving structure. Begin by selectively removing the oldest, thickest stems right down to the ground; this technique, called thinning, promotes healthier, younger canes from the base. After thinning, reduce the remaining stems by heading them back, which shortens the branches to control the shrub’s size. A general rule is to reduce the shrub’s overall height by approximately one-third.
When performing heading cuts, always use sharp, clean pruners and make the cut just above an outward-facing bud or a branch junction. Cutting above a bud ensures that new growth is directed away from the center of the plant, which helps maintain an open structure and prevents the shrub from becoming too dense. This combination of thinning the oldest canes and heading back the remaining stems is effective for keeping the shrub compact, bushy, and full of colorful new growth.
Restoring Overgrown Shrubs
For shrubs that have become neglected, excessively woody, or too large, a more drastic measure called renewal pruning is necessary. This aggressive approach is typically needed only every three to five years to revitalize an aging plant. The timing for this hard prune remains the same as for routine maintenance: late winter or very early spring while the shrub is dormant.
Renewal pruning involves cutting all the shrub’s stems down to a height of about six to twelve inches from the ground. While this action results in the loss of all flowers for that single growing season, the plant responds by sending up many vigorous new shoots from the base. This process completely resets the plant’s structure, eliminates old, non-productive wood, and ensures the Goldflame Spirea returns as a healthier, more compact shrub with improved flowering and foliage color in subsequent years.