How to Grow Azaleas and Rhododendrons Under Pines

Select high-quality nursery-grown plants. First- and second-year shrubs may only be around 1 to 3 feet tall. They may or may not have blooms or extensive foliage if they're still being grown at a nursery. Take into consideration that some cultivators of azaleas -- such as the Indian Hybrid -- can reach up to 6 feet tall. You'll have to make accommodations when planting under a pine, such as trimming the branches or placing the plants in a location where they will not interfere with the growth of the pine tree.

Locate a planting area for your azaleas and rhododendrons. Choosing a bare area under a pine tree is a good choice, due to the soil and because it helps block intense rays of the sun and protects the shrub from wind damage. The pH level under a pine tree is ideal for rhododendron and azaleas. According to the Clemson Cooperative Extension, azaleas thrive in acidic soil with a pH level between 4.5 and 6.0. The pine needles from the tree also protect the roots from excessive moisture.

Plant your shrubs in well-drained soil under the tree. Work top soil or compost in with the fallen pine needles until the bed is about 6 to 8 inches deep. Ensure the root ball is slightly above ground level. Because many azaleas and rhododendrons can have up to a 6-foot spread, space plants apart appropriately. Temporarily, you can fill in the gap with colorful annual shade flowers such as impatiens and begonias.

Mulch your rhododendrons and azaleas after planting. Use surrounding pine needles or organic mulch to fill in around the shrubs to protect the roots and help retain water.

Water your shrubs as needed. They do not prefer frequent watering, but after the first planting, ensure the soil stays moist and does not puddle up in or around the base of the shrub. While drainage is important, do not over-water the rhododendron or azalea shrub. If the water saturates the roots, it could kill the shrub. It can be challenging to water under a pine tree, on a regular basis, so consider installing a soaker hose.