Answer: Here are a few transplanting suggestions -- maybe these will help you pinpoint the trouble. If the soil underneath the added humus is compacted, break it up with a fork or spade and mix the humus in. Planted the impatiens to the same level that they're growing in their pots. If you bury the stems or expose the roots, they will suffer. After placing them in the transplant holes, gently firm the soil around the roots, and water well. Add more soil around the roots if watering exposes some pockets of air.
Is the shade you mentioned provided by a black walnut, by chance? Black walnuts produce a substance (juglone) from their roots that kills many plants that try to grow in their shade. An alternative is to grow plants in pots or planters instead. Some plants that show a tolerance to juglone are: coral bells 'Pluie de Feu', Hosta fortunei 'Glauca', herb robert (Geranium robertianum), cranesbill, lamb's ear, and bellflower.
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