Troubleshooting
Prostrate Blue Noble Fir problems — and how to fix them
Prostrate Blue Noble Fir (Abies procera 'Glauca Prostrata') is generally low-drama, but a few issues come up again and again. Here is what each one looks like, why it happens, and the fix.
Root rot (Phytophthora cinnamomi)
The most common killer of this cultivar; caused by waterlogged soil. Symptoms include yellowing needles, dieback from branch tips, and a resinous smell at the base. Improve drainage immediately and apply a phosphonate-based fungicide drench.
Adelgids (Adelges spp.)
Woolly adelgids form white, waxy tufts at the base of needles and on new shoots, causing needle yellowing and premature drop. Treat with a horticultural oil spray in late winter before bud break, or a systemic neonicotinoid applied to the soil.
Prevent prostrate blue noble fir problems before they start
Most prostrate blue noble fir issues are care-mismatch, not bad luck. Dial in the basics:
Prostrate Blue Noble Fir problems — FAQ
Why is my prostrate blue noble fir root rot (phytophthora cinnamomi)?
The most common killer of this cultivar; caused by waterlogged soil. Symptoms include yellowing needles, dieback from branch tips, and a resinous smell at the base. Improve drainage immediately and apply a phosphonate-based fungicide drench.
Why is my prostrate blue noble fir adelgids (adelges spp.)?
Woolly adelgids form white, waxy tufts at the base of needles and on new shoots, causing needle yellowing and premature drop. Treat with a horticultural oil spray in late winter before bud break, or a systemic neonicotinoid applied to the soil.