Troubleshooting
Spiraea 'Anthony Waterer' problems — and how to fix them
Spiraea 'Anthony Waterer' (Spiraea japonica 'Anthony Waterer') is generally forgiving once you match its basics, but a few issues come up again and again. Here is what each one looks like, why it happens, and the fix.
Powdery mildew
A common late-season problem, especially in congested plantings with poor airflow. Apply a fungicide early or improve spacing and air circulation.
Aphids
Pink new spring growth is attractive to aphids. Treat early with insecticidal soap before populations build up.
Spider mites
Stippled, dull foliage with fine webbing in hot dry weather indicates spider mites. Mist the foliage; treat with an appropriate miticide if necessary.
Reverting to all-green growth
If variegated-leaved shoots appear (this cultivar has occasional variegated sports), remove all-green reverted growth promptly to maintain consistency.
Reduced flowering
Usually caused by over-shading or incorrect pruning. This is a summer bloomer flowering on new growth — hard prune in early spring to stimulate vigorous new flowering shoots.
Prevent spiraea 'anthony waterer' problems before they start
Most spiraea 'anthony waterer' issues are care-mismatch, not bad luck. Dial in the basics:
Spiraea 'Anthony Waterer' problems — FAQ
Why is my spiraea 'anthony waterer' powdery mildew?
A common late-season problem, especially in congested plantings with poor airflow. Apply a fungicide early or improve spacing and air circulation.
Why is my spiraea 'anthony waterer' aphids?
Pink new spring growth is attractive to aphids. Treat early with insecticidal soap before populations build up.
Why is my spiraea 'anthony waterer' spider mites?
Stippled, dull foliage with fine webbing in hot dry weather indicates spider mites. Mist the foliage; treat with an appropriate miticide if necessary.
Why is my spiraea 'anthony waterer' reverting to all-green growth?
If variegated-leaved shoots appear (this cultivar has occasional variegated sports), remove all-green reverted growth promptly to maintain consistency.
Why is my spiraea 'anthony waterer' reduced flowering?
Usually caused by over-shading or incorrect pruning. This is a summer bloomer flowering on new growth — hard prune in early spring to stimulate vigorous new flowering shoots.