Answer: At this time of year, this may simply be a natural occurrence. It could also be a sign of nutrient deficiency. Shrubs low in nitrogen have green new growth and yellowing older growth. Nitrogen is available in most fertilizers. The yellowing (chlorosis) related to iron deficiency looks different; the leaf turns yellow but the veins stay green. Add chelated iron (available at garden stores) to the soil as directed on the package. In heavy clay soil, yellow leaves could be a sign of overwatering. Cut back on water to see if this is so. Otherwise, ceanothus sometimes produces a few yellow leaves in the heat of summer. As long as there is still green new growth, it shouldn?t be a problem.
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