Answer: Yellowing of the older leaves can indicate several things, from overwatering to a lack of nitrogen. In my experience impatiens need a rich soil to grow and bloom well just like any other annual. Amending the soil with compost and then applying a complete fertilizer according to the label instructions should keep them blooming strongly. You may find that the long release fertilizers are sensitive to the soil temperature so that you may want to supplement with a faster release form of nitrogen (either a granular or a water soluble form) early in the season when the plants need an extra boost.
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