Answer: Newly planted junipers might turn brown for a number of reasons, but the two most common are over and underwatering. Junipers do best in a very sunny, well-drained spot, meaning not soggy, but they also need regular watering from either the gardener or the sky until they become established. The general rule for this is an inch of water a week. To check if the soil is dry or moist, stick your finger into the soil and see.
Another possibility is that they are planted deeper than they grew originally or they have "settled" since you planted them. You might also check to see that the mulch is not piled up touching the stems at the center of the plant.
Junipers are occasionally subject to a number of pests and diseases. Unfortunately, based on your description it is impossible to give you a definite diagnosis for your plants. You might wish to take a sample and a photograph of the plants to your County Extension office for positive identification of the problem and suggested controls, if any. Their telephone number is 421-6430.
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