Q.Can I plant azaleas and hydrangeas next to blue point junipers? I’ve heard they are poisonous to other plants
4 young blue point bushes along the fence. Planning to plant azaleas and other decorative bushes in front of junipers.

Junipers do not poison the soil in the sense that black walnut does. However, a mature plant has very dense shallow roots that make it difficult to plant all but the most drought tolerant plants nearby. Roots typically extend beyond the "drip line" by 50%. Blue Point juniper may grow to 8 feet wide which means its roots may extend 6 feet from the trunk. Planting azalea or hydrangea within that 6 foot span may yield disappointing results as the juniper roots grow. They should be fine if planted outside the juniper's root zone. Junipers look the best in full sun. They tolerate different soils and pH well except for soils that don't drain well. Hydrangea and azalea both like consistently moist soil and morning sun or indirect light. (Endless Summer and similar hybrid hydrangea take more sun.)