Answer: None of these need much fertilizer. This is not a good time of year to fertilize, it could encourage late season growth that would not have time to harden off before winter.
Next spring, you could top dress with a good quality compost and possibly also apply a general purpose granular or slow release fertilizer with an analysis such as 10-10-10 per the label directions.
Using an organic mulch in a flat layer two to three inches thick (no more than two inches around the boxwood) over the root area year round will also help feed the soil slowly as it breaks down over time.
With new plants, correct watering is more important. Make sure the soil is evenly moist like a wrung out sponge, not sopping wet and not dried out. To check it, dig into the soil with your finger.
Enjoy your new shrubs!
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